Sentences Generator
And
Your saved sentences

No sentences have been saved yet

"galactose" Definitions
  1. a sugar C6H12O6 less soluble and less sweet than glucose
"galactose" Synonyms
carbohydrate cellulose glucose lactose starch sugar biological compound dextrin dextrose disaccharide fructose glycogen maltose monosaccharide polysaccharide sucrose complex carbohydrate simple carbohydrate caramel candy

584 Sentences With "galactose"

How to use galactose in a sentence? Find typical usage patterns (collocations)/phrases/context for "galactose" and check conjugation/comparative form for "galactose". Mastering all the usages of "galactose" from sentence examples published by news publications.

type: All Declarative Interrogative Exclamative

structure: All Simple Compound Complex Compound-Complex

length: All <=10 words 10-20 words 20-30 words 30-50 words

Blood tests revealed that the patients had antibodies for galactose-α-1,3-galactose, a.k.a.
The name of the sugar was galactose-alpha-1,3-galactose, known for short as alpha-gal.
It contains a few protein-linked saccharides, including one called galactose-alpha-1,3-galactose, or alpha-gal, for short.
The antibody is formed in response to a compound in red meat known as alpha-gal (short for galactose-alpha-1,3-galactose).
The patients who reacted, he discovered, had allergic antibodies to a complex sugar called galactose-alpha-1,3-galactose, or alpha-gal for short.
The trigger was a sugar, identified as galactose-α-1,3-galactose and more casually known as alpha-gal, a carbohydrate found in the flesh of all nonprimate mammals.
It's also broken down in your small intestine, where it's converted into the monosaccharides, glucose and galactose.
The tick's bite is thought to cause the body to react to a complex sugar molecule (galactose-alpha-1, 5003-galactose, or alpha-gal), which is found in meat, Dr. Jay Lieberman, the vice chair of the American College of Allergy, Asthma, and Immunology's Food Allergy Committee, told BuzzFeed News.
When these altered yeast cells were exposed to galactose, the variation in their number of copies of the gene changed, too.
A baby with galactosemia, a metabolic disorder that prevents the baby from metabolizing galactose, will die or suffer brain damage from breastfeeding.
Spraying experimental rice plants with artificial acid rain immediately cut their release into the soil of three relevant bacterial foodstuffs—fumaric acid, galactose and glucose.
To rule out that possibility, the researchers cleverly re-engineered the CUP1 gene so that it would respond to a harmless, nonmutagenic sugar, galactose, instead of copper.
Every single cell in the human body is covered with a collection of glycans which are assembled using various simple sugars like glucose, mannose, galactose, sialic acid, glucosamine and frucose as building blocks.
Galactose oxidase (D-galactose:oxygen 6-oxidoreductase, D-galactose oxidase, beta-galactose oxidase; abbreviated GAO, GAOX, GOase; ) is an enzyme that catalyzes the oxidation of D-galactose in some species of fungi. Galactose oxidase belongs to the family of oxidoreductases. Copper ion is required as a cofactor for galactose oxidase. A remarkable feature of galactose oxidase is that it is a free radical enzyme.
No direct catabolic pathways exist for galactose metabolism. Galactose is therefore preferentially converted into glucose-1-phosphate, which may be shunted into glycolysis or the inositol synthesis pathway. GALE functions as one of four enzymes in the Leloir pathway of galactose conversion of glucose-1-phosphate. First, galactose mutarotase converts β-D-galactose to α-D-galactose.
Intermediates and enzymes in the Leloir pathway of galactose metabolism The Leloir pathway is a metabolic pathway for the catabolism of D-galactose. It is named after Luis Federico Leloir. In the first step, galactose mutarotase facilitates the conversion of β-D-galactose to α-D-galactose since this is the active form in the pathway. Next, α-D-galactose is phosphorylated by galactokinase to galactose 1-phosphate.
The Leloir pathway catalyzes the conversion of galactose to glucose. Galactose is found in dairy products, as well as in fruits and vegetables, and can be produced endogenously in the breakdown of glycoproteins and glycolipids. Three enzymes are required in the Leloir pathway: galactokinase, galactose-1-phosphate uridylyltransferase, and UDP-galactose 4-epimerase. Galactokinase catalyzes the first committed step of galactose catabolism, forming galactose 1-phosphate.
In enzymology, a galactose-1-phosphate thymidylyltransferase () is an enzyme that catalyzes the chemical reaction :dTTP + alpha-D-galactose 1-phosphate \rightleftharpoons diphosphate + dTDP-galactose Thus, the two substrates of this enzyme are dTTP and alpha-D-galactose 1-phosphate, whereas its two products are diphosphate and dTDP-galactose. This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is dTTP:alpha-D-galactose-1-phosphate thymidylyltransferase. Other names in common use include dTDP galactose pyrophosphorylase, galactose 1-phosphate thymidylyl transferase, thymidine diphosphogalactose pyrophosphorylase, thymidine triphosphate:alpha-D-galactose 1-phosphate, and thymidylyltransferase.
In the third step, D-galactose-1-phosphate uridylyltransferase converts galactose 1-phosphate to UDP-galactose using UDP-glucose as the uridine diphosphate source. Finally, UDP-galactose 4-epimerase recycles the UDP-galactose to UDP-glucose for the transferase reaction. Additionally, phosphoglucomutase converts the D-glucose 1-phosphate to D-glucose 6-phosphate.
This process is catalyzed by the enzyme galactose-1-phosphate uridyl transferase and transfers the UDP to the galactose molecule. The end result is UDP-galactose and glucose-1-phosphate. This process is continued to allow the proper glycolysis of galactose.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is UTP:alpha-D-hexose-1-phosphate uridylyltransferase. Other names in common use include galactose-1-phosphate uridylyltransferase, galactose 1-phosphate uridylyltransferase, alpha-D- galactose 1-phosphate uridylyltransferase, galactose 1-phosphate uridyltransferase, UDPgalactose pyrophosphorylase, uridine diphosphate galactose pyrophosphorylase, and uridine diphosphogalactose pyrophosphorylase. This enzyme participates in galactose metabolism and nucleotide sugars metabolism.
Uridine plays a role in the glycolysis pathway of galactose. There is no catabolic process to metabolize galactose. Therefore, galactose is converted to glucose and metabolized in the common glucose pathway. Once the incoming galactose has been converted into galactose 1-phosphate (Gal-1-P), it is involved in a reaction with UDP-glucose, a glucose molecule bonded to uridine diphosphate (UDP).
In enzymology, an UDP-galactose—UDP-N-acetylglucosamine galactose phosphotransferase () is an enzyme that catalyzes the chemical reaction :UDP- galactose + UDP-N-acetyl-D-glucosamine \rightleftharpoons UMP + UDP-N- acetyl-6-(D-galactose-1-phospho)-D-glucosamine Thus, the two substrates of this enzyme are UDP-galactose and UDP-N-acetyl-D-glucosamine, whereas its two products are UMP and UDP-N-acetyl-6-(D-galactose-1-phospho)-D-glucosamine. This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups transferases for other substituted phosphate groups. The systematic name of this enzyme class is UDP- galactose:UDP-N-acetyl-D-glucosamine galactose phosphotransferase. Other names in common use include uridine diphosphogalactose-uridine diphosphoacetylglucosamine galactose-1-phosphotransferase, galactose-1-phosphotransferase, and galactosyl phosphotransferase.
GDP-L-galactose phosphorylase (, VTC2, VTC5) is an enzyme with systematic name GDP:alpha-L-galactose 1-phosphate guanylyltransferase. This enzyme catalyses the following chemical reaction : GDP-L-galactose + phosphate \rightleftharpoons alpha-L-galactose 1-phosphate + GDP The enzyme catalyses a reaction of the Smirnoff-Wheeler pathway.
In yeasts, galactose oxidase catalyzes the following reaction: :D-galactose + O2 \rightleftharpoons D-galacto-hexodialdose + H2O2 This reaction is essentially the oxidation of primary alcohol using dioxygen to form the corresponding aldehyde and hydrogen peroxide. It has been shown that galactose oxidase is also able to catalyze various primary alcohols other than galactose. In fact, galactose oxidase catalyzes dihydroxyacetone three times faster than it does to galactose. The reaction is regioselective, in that it cannot oxidize secondary alcohol.
Galactose is a component of the antigens present on blood cells that determine blood type within the ABO blood group system. In O and A antigens, there are two monomers of galactose on the antigens, whereas in the B antigens there are three monomers of galactose. A disaccharide composed of two units of galactose, galactose-alpha-1,3-galactose (alpha-gal), has been recognized as a potential allergen present in mammal meat. Alpha-gal allergy may be triggered by lone star tick bites.
Galactokinase then phosphorylates α-D-galactose at the 1' hydroxyl group, yielding galactose-1-phosphate. In the third step, galactose-1-phosphate uridyltransferase catalyzes the reversible transfer of a UMP moiety from UDP-glucose to galactose-1-phosphate, generating UDP-galactose and glucose-1-phosphate. In the final Leloir step, UDP-glucose is regenerated from UDP-galactose by GALE; UDP-glucose cycles back to the third step of the pathway. As such, GALE regenerates a substrate necessary for continued Leloir pathway cycling.
Porphyran is a complex sulfated carbohydrate. It is a highly substituted agarose with a linear backbone consisting of 3-linked beta-D-galactosyl units alternating with either 4-linked alpha-L-galactosyl 6-sulfate or 3,6-anhydro-alpha-L-galactosyl units. The composition includes 6-O-sulfated L-galactose, 6-O-methylated D-galactose, L-galactose, 3,6-anhydro-L-galactose, 6-O-methyl D-galactose and ester sulfate. Some of the ester is present as 1-4-linked L-galactose 6-sulfate.
In enzymology, an UTP—hexose-1-phosphate uridylyltransferase () is an enzyme that catalyzes the chemical reaction :UTP + alpha-D-galactose 1-phosphate \rightleftharpoons diphosphate + UDP-galactose Thus, the two substrates of this enzyme are UTP and alpha-D-galactose 1-phosphate, whereas its two products are diphosphate and UDP-galactose.
S. humi can also produce acid from D-galactose and assimilate propionate, L-proline, acetate, D-galactose, and valerianate.
GalK encodes for a kinase that phosphorylates α-D-galactose to galactose 1-phosphate. Lastly, galM catalyzes the conversion of β-D-galactose to α-D-galactose as the first step in galactose metabolism. The gal operon contains two operators, OE (for external) and OI (for internal). The former is just upstream of the promoter, and the latter is just after the galE gene (the first gene in the operon).
Infants with DG who continue to drink milk accumulate the same set of abnormal galactose metabolites seen in babies with classic galactosemia – e.g. galactose, Gal-1P, galactonate, and galactitolFicicioglu, C., et al., Monitoring of biochemical status in children with Duarte galactosemia: utility of galactose, galactitol, galactonate, and galactose 1-phosphate. Clin Chem, 2010.
In 1894, Emil Fischer and Robert Morrell determined the configuration of galactose. The configuration of galactose appears on page 385.
In enzymology, a galactose 1-dehydrogenase () is an enzyme that catalyzes the chemical reaction :D-galactose + NAD+ \rightleftharpoons D-galactono-1,4-lactone + NADH + H+ Thus, the two substrates of this enzyme are D-galactose and NAD+, whereas its 3 products are D-galactono-1,4-lactone, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is D-galactose:NAD+ 1-oxidoreductase. Other names in common use include D-galactose dehydrogenase, beta-galactose dehydrogenase, and NAD+-dependent D-galactose dehydrogenase. This enzyme participates in galactose metabolism.
The other common galactose metabolism defect is a defect in galactose-1-phosphate uridylyltransferase, an autosomal recessive disorder, which also causes a buildup of galactitol as a result of increased concentrations of galactose-1-phosphate and galactose. This disorder leads to hepatosplenomegaly and cognitive dysfunction in addition to the cataracts caused by galactitol buildup.
In human lactation, glucose is changed into galactose via hexoneogenesis to enable the mammary glands to secrete lactose. However, most lactose in breast milk is synthesized from galactose taken up from the blood, and only 35±6% is made from galactose from de novo synthesis. Glycerol also contributes some to the mammary galactose production.
DTDP-4-amino-4,6-dideoxy-D-galactose acyltransferase (, TDP-fucosamine acetyltransferase, WECD, RFFC) is an enzyme with systematic name acetyl- CoA:dTDP-4-amino-4,6-dideoxy-alpha-D-galactose N-acetyltransferase. This enzyme catalyses the following chemical reaction : acetyl-CoA + dTDP-4-amino-4,6-dideoxy-alpha-D-galactose \rightleftharpoons CoA + dTDP-4-acetamido-4,6-dideoxy-alpha-D-galactose TDP-4-acetamido-4,6-dideoxy-D- galactose takes part in the biosynthesis of enterobacterial common antigen.
Galactokinases across different species display a great diversity of substrate specificities. E. coli galactokinase can also phosphorylate 2-deoxy-D-galactose, 2-amino-deoxy-D- galactose, 3-deoxy-D-galactose and D-fucose. The enzyme cannot tolerate any C-4 modifications, but changes at the C-2 position of D-galactose do not interfere with enzyme function. Both human and rat galactokinases are also able to successfully phosphorylate 2-deoxy-D-galactose.
However, galactose concentration must be fairly high before the enzyme, aldose reductase, will convert significant amounts of the sugar to its galactitol form. As it turns out, the lens is a favorable site for galactose accumulation. The lens phosphorylates galactose at a relatively slow pace in comparison to other tissues. This factor, in combination with the low activity of galactose- metabolizing enzymes in galactosemic patients, allows for the accumulation of galactose in the lens.
In enzymology, a galactose-6-sulfurylase () is an enzyme that catalyzes the chemical reaction :Eliminates sulfate from the D-galactose 6-sulfate residues of porphyran, producing 3,6-anhydrogalactose residues. This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is D-galactose-6-sulfate:alkyltransferase (cyclizing). Other names in common use include porphyran sulfatase, galactose-6-sulfatase, and galactose 6-sulfatase.
In enzymology, a galactose-6-phosphate isomerase () is an enzyme that catalyzes the chemical reaction :D-galactose 6-phosphate \rightleftharpoons D-tagatose 6-phosphate Hence, this enzyme has one substrate, D-galactose 6-phosphate, and one product, D-tagatose 6-phosphate. This enzyme belongs to the family of isomerases, specifically those intramolecular oxidoreductases interconverting aldoses and ketoses. The systematic name of this enzyme class is D-galactose-6-phosphate aldose-ketose-isomerase. This enzyme participates in galactose metabolism.
When secreted, α-agarases yield oligosaccharides with 3.6 anhydro-L-galactose at the reducing end whereas β-agarases result in D-galactose residues.
In enzymology, a galactose 1-dehydrogenase (NADP+) () is an enzyme that catalyzes the chemical reaction :D-galactose + NADP+ \rightleftharpoons D-galactonolactone + NADPH + H+ Thus, the two substrates of this enzyme are D-galactose and NADP+, whereas its 3 products are D-galactonolactone, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is D-galactose:NADP+ 1-oxidoreductase. Other names in common use include D-galactose dehydrogenase (NADP+), and galactose 1-dehydrogenase (NADP+). This enzyme participates in galactose metabolism.
Lactose, or milk sugar, consists of one molecule of glucose and one molecule of galactose. After separation from glucose, galactose travels to the liver for conversion to glucose. Galactokinase uses one molecule of ATP to phosphorylate galactose. The phosphorylated galactose is then converted to glucose-1-phosphate, and then eventually glucose-6-phosphate, which can be broken down in glycolysis.
Rhodophyta, the phylum of red algae, has a cell wall composed of sulfated galactans. Agarans, a main component of the cell wall is composed of alternating 3-linked β-D-galactose and 4-linked α-L-galactose. Porphyran is a water-soluble agaran found in Porphyra. The porphyran backbone is composed of roughly 30% 3-linked β-D-galactose and 4-linked 3,6-anhydro-α-L-galactose.
Diagnosis is established by high blood levels of galactose, normal activity of the enzyme galactose-1-phosphate uridyltransferase and reduced or no activity of galactokinase in RBCs.
The structure of the repeating unit of an agarose polymer. Agarose is a linear polymer with a molecular weight of about 120,000, consisting of alternating D-galactose and 3,6-anhydro-L-galactopyranose linked by α-(1→3) and β-(1→4) glycosidic bonds. The 3,6-anhydro-L-galactopyranose is an L-galactose with an anhydro bridge between the 3 and 6 positions, although some L-galactose units in the polymer may not contain the bridge. Some D-galactose and L-galactose units can be methylated, and pyruvate and sulfate are also found in small quantities.
GALK deficient patients exposed to high-galactose diets show extreme levels of galactitol in blood and urine. Studies on galactokinase-deficient patients have shown that nearly two- thirds of ingested galactose can be accounted for by galactose and galactitol levels in the urine. Urinary levels of galactitol in these subjects approach 2500 mmol/mol creatine as compared to 2 to 78 mmol/mol creatine in control patients. A decrease in activity in the third major enzymes of galactose metabolism, UDP galactose-4'-epimerase (GALE), is the cause of Type III galactosemia.
Galactosemia is one of the most mysterious of the heavily- researched metabolic diseases. It is a hereditary disease that results in a defect in, or absence of, galactose-metabolizing enzymes. This inborn error leaves the body unable to metabolize galactose, allowing toxic levels of galactose to build up in human body blood, cells, and tissues. Although treatment for galactosemic infants is a strict galactose-free diet, endogenous (internal) production of galactose can cause symptoms such as long-term morbidity, presenile development of cataract, renal failure, cirrhosis, and cognitive, neurologic, and female reproductive complications.
A galactoside is a glycoside containing galactose. The H of the OH group on carbon-1 of galactose is replaced by an organic moiety. Depending on whether the glycosidic bond lies "above" or "below" the plane of the galactose molecule, galactosides are classified as α-galactosides or β-galactosides. A β-galactoside is a type of galactoside in which the glycosidic bond lies above the plane of the galactose residue.
In nature, lactose is found primarily in milk and milk products. Consequently, various food products made with dairy-derived ingredients can contain lactose. Galactose metabolism, which converts galactose into glucose, is carried out by the three principal enzymes in a mechanism known as the Leloir pathway. The enzymes are listed in the order of the metabolic pathway: galactokinase (GALK), galactose-1-phosphate uridyltransferase (GALT), and UDP-galactose-4’-epimerase (GALE).
L-galactose 1-dehydrogenase (, L-GalDH, L-galactose dehydrogenase) is an enzyme with the systematic name L-galactose:NAD+ 1-oxidoreductase. This enzyme catalyses the following chemical reaction: : L-galactose + NAD+ \rightleftharpoons L-galactono-1,4-lactone + NADH + H+ The enzyme catalyses a step in the ascorbate biosynthesis in higher plants.
Tagatose is a natural sweetener present in only small amounts in fruits, cacao, and dairy products. Starting with lactose, which is hydrolyzed to glucose and galactose, tagatose can then be produced commercially from the resulting galactose. The galactose is isomerized under alkaline conditions to D-tagatose by calcium hydroxide.
An experiment was conducted in which guinea pigs were fed a normal, high vitamin C diet with 10-percent galactose or a scorbutic diet plus 10-percent galactose.
Accumulated galactose can also undergo an alternative reaction: Oxidation to galactonate. The mechanism of galactonate formation is still unclear. However, recent studies suggest that galactose dehydrogenase is responsible for converting galactose to galactonolactone, which then spontaneously or enzymatically converts to galactonate. Once formed, galactonate may enter the pentose phosphate pathway.
Galactokinase deficiency, is an autosomal recessive metabolic disorder marked by an accumulation of galactose and galactitol secondary to the decreased conversion of galactose to galactose-1-phosphate by galactokinase. The disorder is caused by mutations in the GALK1 gene, located on chromosome 17q24. Galactokinase catalyzes the first step of galactose phosphorylation in the Leloir pathway of intermediate metabolism. Galactokinase deficiency is one of the three inborn errors of metabolism that lead to hypergalactosemia.
Mono- and disaccharides, specifically galactose and lactose are potent binding inhibitors of Modeccin. This is related to the necessity of terminal galactose residues in Modeccin binding sites on cell-membranes.
In 1855, E. O. Erdmann noted that hydrolysis of lactose produced a substance besides glucose. see especially p. 673. Galactose was first isolated and studied by Louis Pasteur in 1856 and he called it "lactose". In 1860, Berthelot renamed it "galactose" or "glucose lactique"."Galactose" — from the Ancient Greek γάλακτος (gálaktos, “milk”).
Galactosemia (British galactosaemia, from Greek γαλακτόζη + αίμα, meaning galactose + blood, accumulation of galactose in blood) is a rare genetic metabolic disorder that affects an individual's ability to metabolize the sugar galactose properly. Galactosemia follows an autosomal recessive mode of inheritance that confers a deficiency in an enzyme responsible for adequate galactose degradation. Friedrich Goppert (1870–1927), a German physician, first described the disease in 1917, with its cause as a defect in galactose metabolism being identified by a group led by Herman Kalckar in 1956. Its incidence is about 1 per 60,000 births for people of European ancestry.
The gal operon of E. coli consists of 4 structural genes: galE (epimerase), galT (galactose transferase), galK (galactokinase), and galM (mutarotase) which are transcribed from two overlapping promoters, PG1 (+1) and PG2 (-5), upstream from galE. GalE encodes for an epimerase that converts UDP-glucose into UDP- galactose. This is required for the formation of UDP-galactose for cell wall biosynthesis, in particular the cell wall component lipopolysaccharide, even when cells are not using galactose as a carbon/energy source. GalT encodes for the protein galactosyltransferase which catalyzes the transfer of a galactose sugar to an acceptor, forming a glycosidic bond.
In enzymology, an undecaprenyl-phosphate galactose phosphotransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + undecaprenyl phosphate \rightleftharpoons UMP + alpha-D-galactosyl-diphosphoundecaprenol Thus, the two substrates of this enzyme are UDP-galactose and undecaprenyl phosphate, whereas its two products are UMP and alpha-D-galactosyl- diphosphoundecaprenol. This enzyme belongs to the family of transferases, specifically those transferring non-standard substituted phosphate groups. The systematic name of this enzyme class is UDP-galactose:undecaprenyl-phosphate galactose phosphotransferase. Other names in common use include poly(isoprenol)-phosphate galactose phosphotransferase, poly(isoprenyl)phosphate galactosephosphatetransferase, and undecaprenyl phosphate galactosyl-1-phosphate transferase.
Then, Asp-231 serves as an acid to remove a proton from water, making it more nucleophilic to attack the galactose-Asp complex and release α-galactose from the active site.
Each 100 mg etravirine tablet contains 160 mg of lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose- galactose malabsorption should not take this medicine.
Intermediates and enzymes in the Leloir pathway of galactose metabolism.
This enzyme participates in galactose metabolism and nucleotide sugars metabolism.
Chronic systemic exposure of mice, rats, and Drosophila to D-galactose causes the acceleration of senescence (aging). It has been reported that high dose exposure of D-galactose (120 mg/Kg) can cause reduced sperm concentration and sperm motility in rodent and has been extensively used as an aging model when administered subcutaneous. Two studies have suggested a possible link between galactose in milk and ovarian cancer. Other studies show no correlation, even in the presence of defective galactose metabolism.
In enzymology, an UDP-glucose—hexose-1-phosphate uridylyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-glucose + alpha-D-galactose 1-phosphate \rightleftharpoons alpha-D-glucose 1-phosphate + UDP-galactose Thus, the two substrates of this enzyme are UDP-glucose and alpha-D-galactose 1-phosphate, whereas its two products are alpha-D-glucose 1-phosphate and UDP- galactose. This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is UDP- glucose:alpha-D-galactose-1-phosphate uridylyltransferase. Other names in common use include uridyl transferase, hexose-1-phosphate uridylyltransferase, uridyltransferase, and hexose 1-phosphate uridyltransferase.
In enzymology, an abequosyltransferase () is an enzyme that catalyzes the chemical reaction :CDP-abequose + D-mannosyl-L-rhamnosyl-D- galactose-1-diphospholipid \rightleftharpoons CDP + D-abequosyl-D-mannosyl- rhamnosyl-D-galactose-1-diphospholipid Thus, the two substrates of this enzyme are CDP-abequose and D-mannosyl-L-rhamnosyl-D-galactose-1-diphospholipid, whereas its two products are CDP and D-abequosyl-D-mannosyl-rhamnosyl-D- galactose-1-diphospholipid. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is CDP-abequose:D-mannosyl-L-rhamnosyl-D- galactose-1-diphospholipid D-abequosyltransferase. This enzyme is also called trihexose diphospholipid abequosyltransferase.
In enzymology, a monogalactosyldiacylglycerol synthase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + 1,2-diacyl-sn-glycerol \rightleftharpoons UDP + 3-beta-D-galactosyl-1,2-diacyl-sn-glycerol Thus, the two substrates of this enzyme are UDP-galactose and 1,2-diacyl-sn-glycerol, whereas its two products are UDP and 3-beta-D-galactosyl-1,2-diacyl-sn- glycerol. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:1,2-diacyl-sn-glycerol 3-beta-D-galactosyltransferase. Other names in common use include uridine diphosphogalactose-1,2-diacylglycerol galactosyltransferase, UDP-galactose:diacylglycerol galactosyltransferase, MGDG synthase, UDP galactose-1,2-diacylglycerol galactosyltransferase, UDP- galactose-diacylglyceride galactosyltransferase, UDP- galactose:1,2-diacylglycerol 3-beta-D-galactosyltransferase, 1beta-MGDG, and 1,2-diacylglycerol 3-beta-galactosyltransferase.
The enzyme does not cleave β-linked galactose, as in lactose.
Active site structure of galactose oxidase with coordinating ligands shown. The indole ring of Trp290 forms a "shield" protecting the active site. Note the lengthened copper-solvent bond. Galactose oxidase is a type II copper protein.
In enzymology, a dTDP-4-amino-4,6-dideoxygalactose transaminase () is an enzyme that catalyzes the chemical reaction :dTDP-4-amino-4,6-dideoxy-D- galactose + 2-oxoglutarate \rightleftharpoons dTDP-4-dehydro-6-deoxy-D- galactose + L-glutamate Thus, the two substrates of this enzyme are dTDP-4-amino-4,6-dideoxy-D-galactose and 2-oxoglutarate, whereas its two products are dTDP-4-dehydro-6-deoxy-D-galactose and L-glutamate. This enzyme belongs to the family of transferases, specifically the transaminases, which transfer nitrogenous groups. The systematic name of this enzyme class is dTDP-4,6-dideoxy-D-galactose:2-oxoglutarate aminotransferase. Other names in common use include thymidine diphosphoaminodideoxygalactose aminotransferase, and thymidine diphosphate 4-keto-6-deoxy-D-glucose transaminase.
Lactase is a disaccharidase that breaks down lactose into glucose and galactose.
Melibiose is a reducing disaccharide formed by an α-1,6 linkage between galactose and glucose (D-Gal-α(1→6)-D-Glc). It differs from lactose in the chirality of the carbon where the galactose ring is closed and that the galactose is linked to a different point on the glucose moiety. It can be formed by invertase-mediated hydrolysis of raffinose, which produces melibiose and fructose. Melibiose can be broken down into its component saccharides, glucose and galactose, by the enzyme alpha-galactosidase, such as MEL1 from Saccharomyces pastorianus (lager yeast).
Enzyme converted to type O (ECO) technology to convert blood type B to blood type O. Red blood cell (RBC) surfaces are decorated with the glycoproteins and glycolipids that have the same basic sequence with terminal sugar α1‐2‐linked fucose linked to the penultimate galactose. This galactose molecule is called the H antigen. Blood type A, B, AB, and O differ only in the sugar (red molecule in the illustration) linked with the penultimate galactose. For blood type B, this linked sugar is an α-1‐3‐linked galactose.
56(7): p. 1177-82. – but to a lesser extent. While it remains unclear whether any of these metabolites contribute to the long-term developmental complications experienced by so many older children with classic galactosemia, the theoretical possibility that they might cause problems in children with DG serves to motivate some healthcare providers to recommend dietary galactose restriction for infants with DG. Switching an infant with DG from milk or milk formula (high galactose) to a low-galactose formula rapidly normalizes their galactose metabolites. This approach is considered potentially preventative rather than responsive to symptoms.
Duarte galactosemia is an inherited condition associated with diminished ability to metabolize galactose due to a partial deficiency of the enzyme galactose-1-phosphate uridylyltransferase.Fridovich-Keil, J., et al., Duarte Variant Galactosemia, in GeneReviews, R. Pagon, et al., Editors.
Mucic acid, C6H10O8 or HOOC-(CHOH)4-COOH (also known as galactaric or meso- galactaric acid) is an aldaric acid obtained by nitric acid oxidation of galactose or galactose-containing compounds such as lactose, dulcite, quercite, and most varieties of gum.
Galactokinase is an enzyme (phosphotransferase) that facilitates the phosphorylation of α-D-galactose to galactose 1-phosphate at the expense of one molecule of ATP. Galactokinase catalyzes the second step of the Leloir pathway, a metabolic pathway found in most organisms for the catabolism of β-D-galactose to glucose 1-phosphate. First isolated from mammalian liver, galactokinase has been studied extensively in yeast, archaea, plants, and humans.
In enzymology, a GDP-mannose 3,5-epimerase () is an enzyme that catalyzes the chemical reaction :GDP-mannose \rightleftharpoons GDP-L-galactose + GDP-L- gulose Hence, this enzyme has one substrate, GDP-mannose, and two products, GDP-L-galactose and GDP-L-gulose This enzyme belongs to the family of isomerases, specifically those racemases and epimerases acting on carbohydrates and derivatives. The systematic name of this enzyme class is GDP-mannose 3,5-epimerase. Other names in common use include GDP-D- mannose:GDP-L-galactose epimerase, guanosine 5'-diphosphate D-mannose:guanosine 5'-diphosphate, and L-galactose epimerase. This enzyme participates in ascorbate and aldarate metabolism.
Using α-GAL, this terminal galactose molecule can be removed, converting RBC to type O.
UDP-galactose translocator is a protein that in humans is encoded by the SLC35A2 gene.
This occurs via the following pathway: UDP-β-D-galactose + D-glucose \rightleftharpoons UDP + lactose.
In chemical terms, agar is a polymer made up of subunits of the sugar galactose.
In enzymology, a digalactosyldiacylglycerol synthase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + 3-(beta-D- galactosyl)-1,2-diacyl-sn-glycerol \rightleftharpoons UDP + 3-[alpha-D- galactosyl-(1->6)-beta-D-galactosyl]-1,2-diacyl-sn- glycerol Thus, the two substrates of this enzyme are UDP-galactose and 3-(beta-D- galactosyl)-1,2-diacyl-sn-glycerol, whereas its 3 products are UDP, 3-[alpha- D-galactosyl-(1->6)-beta-D-galactosyl]-1,2-diacyl-sn-, and glycerol. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP- galactose:3-(beta-D-galactosyl)-1,2-diacyl-sn-glycerol 6-alpha- galactosyltransferase. Other names in common use include DGD1, DGD2, DGDG synthase (ambiguous), UDP-galactose-dependent DGDG synthase, UDP-galactose- dependent digalactosyldiacylglycerol synthase, and UDP-galactose:MGDG galactosyltransferase.
A simplified representation of a lactose molecule being broken down into glucose (2) and galactose (1) Milk contains several different carbohydrate including lactose, glucose, galactose, and other oligosaccharides. The lactose gives milk its sweet taste and contributes approximately 40% of whole cow's milk's calories. Lactose is a disaccharide composite of two simple sugars, glucose and galactose. Bovine milk averages 4.8% anhydrous lactose, which amounts to about 50% of the total solids of skimmed milk.
Biomolecules in samples such as galactose can be quantified using oxygen detection method, since one equivalent consumption of oxygen corresponds to one equivalent primary hydroxyl group oxidized. The formation of hydrogen peroxide during substrate oxidation can also be used for colorimetric detection of galactose using dyes that are oxidized by hydrogen peroxide. Because carbohydrates can normally have primary hydroxyl groups, galactose oxidase can be used to modify cell surface glycoproteins to achieve cell labelling.
Galactosemia is caused by mutations in the gene that makes the enzyme galactose-1-phosphate uridylyltransferase. Approximately 70% of galactosemia-causing alleles have a single missense mutation in exon 6. A milder form of galactosemia, called Galactokinase deficiency, is caused a lack of the enzyme uridine diphosphate galactose-4-epimerase which breaks down a byproduct of galactose. This type of is associated with cataracts, but does not cause growth failure, mental retardation, or hepatic disease.
Galactose (, galacto- + -ose, "milk sugar") sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecule linked with a glucose molecule forms a lactose molecule. Galactan is a polymeric form of galactose found in hemicellulose, and forming the core of the galactans, a class of natural polymeric carbohydrates.
A galactosylceramide A galactosylceramide, or galactocerebroside is a type of cerebroside consisting of a ceramide with a galactose residue at the 1-hydroxyl moiety. The galactose is cleaved by galactosylceramidase. Galactosylceramide is a marker for oligodendrocytes in the brain, whether or not they form myelin.
This enzyme participates in galactose metabolism and ascorbate and aldarate metabolism. It employs one cofactor, calcium.
Neither the - and -forms are fermentable by yeast. Gulose is a C-3 epimer of galactose.
In enzymology, a dTDP-galactose 6-dehydrogenase () is an enzyme that catalyzes the chemical reaction :dTDP-D-galactose + 2 NADP+ \+ H2O \rightleftharpoons dTDP-D-galacturonate + 2 NADPH + 2 H+ The 3 substrates of this enzyme are dTDP-D-galactose, NADP+, and H2O, whereas its 3 products are dTDP-D- galacturonate, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is dTDP-D- galactose:NADP+ 6-oxidoreductase. This enzyme is also called thymidine- diphosphate-galactose dehydrogenase. This enzyme participates in nucleotide sugars metabolism.
In galactosemic patients, the accumulation of galactose becomes the substrate for enzymes that catalyze the polyol pathway of carbohydrate metabolism. The first reaction of this pathway is the reduction of aldoses, types of sugars including galactose, to sugar alcohols.Kolatkar, Nikheel Dr. "Aldose Rudctase Inhibitors." Your Total Health.
Intake of carbohydrates which must be converted to G6P to be utilized (e.g., galactose and fructose) should be minimized. Although elemental formulas are available for infants, many foods contain fructose or galactose in the forms of sucrose or lactose. Adherence becomes a contentious treatment issue after infancy.
Galactose is a monosaccharide. When combined with glucose (monosaccharide), through a condensation reaction, the result is the disaccharide lactose. The hydrolysis of lactose to glucose and galactose is catalyzed by the enzymes lactase and β-galactosidase. The latter is produced by the lac operon in Escherichia coli.
Galactose-3-O-sulfotransferase 4 is an enzyme that in humans is encoded by the GAL3ST4 gene. This gene encodes a member of the galactose-3-O-sulfotransferase protein family. The product of this gene catalyzes sulfonation by transferring a sulfate to the C-3' position of galactose residues in O-linked glycoproteins. This enzyme is highly specific for core 1 structures, with asialofetuin, Gal-beta-1,3-GalNAc and Gal-beta-1,3 (GlcNAc-beta-1,6)GalNAc being good substrates.
Synthesis of sulfatide Sulfatide synthesis begins with a reaction between UDP- galactose and 2-hydroxylated or non-hydroxylated ceramide. This reaction is catalyzed by galactosyltransferase (CGT), where galactose is transferred to 2-hydroxylated, or non-hydroxylated ceramide, from UDP-galactose. This reaction occurs in the luminal leaflet of the endoplasmic reticulum, and its final product is GalCer, or galactocerebroside, which is then transported to the Golgi apparatus. Here, GalCer reacts with 3’-phosphoadenosine-5’-phosphosulfate (PAPS) to make sulfatide.
In enzymology, a ganglioside galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + N-acetyl-D- galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-1,4-beta-D-glucosyl-N- acylsphingosine \rightleftharpoons UDP + D-galactosyl-1,3-beta-N-acetyl-D- galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosyl-N-acylsphingosine The 2 substrates of this enzyme are UDP-galactose and N-acetyl-D- galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-1,4-beta-D-glucosyl-N- acylsphingosine, whereas its 2 products are UDP and D-galactosyl-1,3-beta-N- acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosyl-N- acylsphingosine. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galac tosyl- D-glucosyl-N-acylsphingosine beta-1,3-D-galactosyltransferase. Other names in common use include UDP-galactose-ceramide galactosyltransferase, uridine diphosphogalactose-ceramide galactosyltransferase, UDP galactose-LAC Tet- ceramide alpha-galactosyltransferase, UDP-galactose-GM2 galactosyltransferase, uridine diphosphogalactose-GM2 galactosyltransferase, uridine diphosphate D-galactose:glycolipid galactosyltransferase, UDP- galactose:N-acetylgalactosaminyl-(N-acetylneuraminyl), galactosyl-glucosyl- ceramide galactosyltransferase, UDP-galactose-GM2 ganglioside galactosyltransferase, and GM1-synthase.
Plant Physiol., 74, 247-251. and increase hydrophilicity. Generally the serine has a single galactose attached.Lamport,D.
Glycated hemoglobin (HbA1c, hemoglobin A1c, A1c, or less commonly HbA1c, HgbA1c, Hb1c, etc.) is a form of hemoglobin (Hb) that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose and fructose, spontaneously (i.e. non-enzymatically) bond with hemoglobin, when present in the bloodstream of humans. However, glucose is less likely to do so than galactose and fructose (13% that of fructose and 21% that of galactose), which may explain why glucose is used as the primary metabolic fuel in humans.
Agar consists of a mixture of two polysaccharides: agarose and agaropectin, with agarose making up about 70% of the mixture. Agarose is a linear polymer, made up of repeating units of agarobiose, a disaccharide made up of D-galactose and 3,6-anhydro-L-galactopyranose. Agaropectin is a heterogeneous mixture of smaller molecules that occur in lesser amounts, and is made up of alternating units of D-galactose and L-galactose heavily modified with acidic side-groups, such as sulfate and pyruvate.Agar at lsbu.ac.
Galactose is the self-released debut EP by The Dead Science under their original name 'The Sweet Science'.
Galactose-3-O-sulfotransferase 3 is an enzyme that in humans is encoded by the GAL3ST3 gene. This gene encodes a member of the galactose-3-O-sulfotransferase protein family. The product of this gene catalyzes sulfonation by transferring a sulfate group to the 3' position of galactose in N-acetyllactosamine in both type 2 (Gal-beta-1-4GlcNAc-R) oligosaccharides and core-2-branched O-glycans, but not on type 1 or core-1-branched structures. This gene, which has also been referred to as GAL3ST2, is different from the GAL3ST2 gene located on chromosome 2 that encodes a related enzyme with distinct tissue distribution and substrate specificities, compared to galactose-3-O-sulfotransferase 3.
In enzymology, a 2-hydroxyacylsphingosine 1-beta-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + 2-(2-hydroxyacyl)sphingosine \rightleftharpoons UDP + 1-(beta-D- galactosyl)-2-(2-hydroxyacyl)sphingosine Thus, the two substrates of this enzyme are UDP-galactose and 2-(2-hydroxyacyl)sphingosine, whereas its two products are UDP and 1-(beta-D-galactosyl)-2-(2-hydroxyacyl)sphingosine. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP- galactose:2-(2-hydroxyacyl)sphingosine 1-beta-D-galactosyl-transferase. Other names in common use include galactoceramide synthase, uridine diphosphogalactose-2-hydroxyacylsphingosine, galactosyltransferase, UDPgalactose-2-hydroxyacylsphingosine galactosyltransferase, UDP- galactose:ceramide galactosyltransferase, and UDP- galactose:2-2-hydroxyacylsphingosine galactosyltransferase.
Galactitol (dulcitol) is a sugar alcohol, the reduction product of galactose. It has a slightly sweet taste. In people with galactokinase deficiency, a form of galactosemia, excess dulcitol forms in the lens of the eye leading to cataracts. Galactitol is produced from galactose in a reaction catalyzed by aldose reductase.
Galactose oxidase has been utilized as a biocatalyst in the synthesis of aldehydes and carboxylic acids from primary alcohols.
Found in several fungal species such as Fusarium graminearum NRRL 2903 (formerly misidentified as Dactylium dendroides), and other species of Fusarium and Aspergillus genera, galactose oxidase was first isolated in 1959. This enzyme is secreted by fungi to function in extracellular space. Although the oxidation reaction of D-galactose gives galactose oxidase its name, the coupled reduction of dioxygen to hydrogen peroxide is believed to have greater physiological significance in yeasts. Hydrogen peroxide which can be produced by yeasts in this way is possibly a bacteriostatic agent.
Chemical structure of galactose. Leloir and his team discovered that in galactosemia, patients lacked the necessary enzyme (Galactose-1-phosphate uridylyltransferase) to convert unusable galactose into usable glucose. At the beginning of 1948, Leloir and his team identified the sugar nucleotides that were fundamental to the metabolism of carbohydrates, turning the Instituto Campomar into a biochemistry institution well known throughout the world. Immediately thereafter, Leloir received the Argentine Scientific Society Prize, one of the many awards he would receive both in Argentina and internationally.
SLC5A1 is medically relevant because of its role in the absorption of glucose and sodium, however, mutations in the gene can cause medical implications. A missense mutation in the SLC5A1 gene of exon 1 can cause problems creating the SGLT1 protein, leading to a rare glucose-galactose malabsorption disease. This is because the mutation destroys the transport function. Glucose-galactose malabsorption occurs when the lining of the intestinal cells cannot take in glucose and galactose which prevents the use of those molecules in catabolism and anabolism.
Alpha-neoagaro-oligosaccharide hydrolase (, alpha-neoagarooligosaccharide hydrolase, alpha-NAOS hydrolase) is an enzyme with systematic name alpha- neoagaro-oligosaccharide 3-glycohydrolase. This enzyme catalyses the following chemical reaction : Hydrolysis of the (1->3)-alpha-L-galactosidic linkages of neoagaro-oligosaccharides that are smaller than a hexamer, yielding 3,6-anhydro-L-galactose and D-galactose When neoagarohexaose is used as a substrate, the oligosaccharide is cleaved at the non-reducing end to produce 3,6-anhydro-L-galactose and agaropentaose, which is further hydrolysed to agarobiose and agarotriose.
In enzymology, a N-acylsphingosine galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + N-acylsphingosine \rightleftharpoons UDP + D-galactosylceramide Thus, the two substrates of this enzyme are UDP-galactose and N-acylsphingosine, whereas its two products are UDP and D-galactosylceramide. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:N-acylsphingosine D-galactosyltransferase. Other names in common use include UDP galactose-N- acylsphingosine galactosyltransferase, and uridine diphosphogalactose- acylsphingosine galactosyltransferase.
Because both galactose and glucose sugars can be added to the ceramide lipid, we have two groups of glycosphingolipids. Galactosphingolipids are generally very simple in structure and the core galactose is not usually modified. Glucosphingolipids, however, are often modified and can become a lot more complex. Biosynthesis of galacto- and glucosphingolipids occurs differently.
The definition of alpha and beta faces for glucose and galactose. The stereochemical difference for two hexoses is highlighted in red. This CH-\pi interaction strongly depends on the stereochemistry of the carbohydrate molecule. For example, consider the top (\beta) and bottom (\alpha) faces of \beta-D-Glucose and \beta-D-Galactose.
CBM32 modules are associated with catalytic modules such as sialidases, B-N-acetylglucosaminidases, α-N- acetylglucosaminidases, mannanases and galactose oxidases.
The sialyl Tn antigen (STn antigen) is formed by elongation with sialic acid (Neu5Ac(a2-6)GalNAc) rather than galactose.
Additional contraindications for the children's formulation are hereditary fructose intolerance, glucose-galactose malabsorption and saccharase deficiency, as it contains sugar.
This causes high levels of galactose in the blood or urine. Affected children can have serious, irreversible effects or even die within days from birth. It is important that newborns be screened for metabolic disorders without delay. Galactosemia can even be detected through NBS before any ingestion of galactose-containing formula or breast milk.
Most of the fructose and galactose travel to the liver, where they can be converted to glucose. Some simple carbohydrates have their own enzymatic oxidation pathways, as do only a few of the more complex carbohydrates. The disaccharide lactose, for instance, requires the enzyme lactase to be broken into its monosaccharide components, glucose and galactose.
Dietary reduction of galactose is also the treatment but not as severe as in patients with classical galactosemia. This deficiency can be systemic or limited to red blood cells and leukocytes. Screening is performed by measuring GAL-1-P urydil transferase activity. Early identification affords prompt treatment, which consists largely of eliminating dietary galactose.
Galactan 1,3-beta-galactosidase (, galactan (1->3)-beta-D-galactosidase) is an enzyme with systematic name galactan 3-beta-D-galactosidase. This enzyme catalyses the following chemical reaction : Hydrolysis of terminal, non- reducing beta-D-galactose residues in (1->3)-beta-D-galactopyranans This enzyme removes not only free galactose, but also 6-glycosylated residues.
The word galactose was coined by Charles Weissman in the mid 19th century and is derived from Greek galaktos (milk) and the generic chemical suffix for sugars -ose. The etymology is comparable to that of the word lactose in that both contain roots meaning "milk sugar". Lactose is a disaccharide of galactose plus glucose.
The disorder is inherited as an autosomal recessive trait. Unlike classic galactosemia, which is caused by deficiency of galactose-1-phosphate uridyltransferase, galactokinase deficiency does not present with severe manifestations in early infancy. Its major clinical symptom is the development of cataracts during the first weeks or months of life, as a result of the accumulation, in the lens, of galactitol, a product of an alternative route of galactose utilization. The development of early cataracts in homozygous affected infants is fully preventable through early diagnosis and treatment with a galactose-restricted diet.
As cataract formation progresses due to galactitol synthesis and subsequent osmotic swelling, changes occur in the lens epithelial cells. For instance, when rabbit lenses are placed in high-galactose mediums, a nearly 40% reduction in lens amino acid levels is observed, along with significant ATP reduction as well. Researchers theorized that this reduction in amino acid and ATP levels during cataract formation is a result of osmotic swelling. To test this theory, Kinoshita placed rabbit lenses in a high-galactose environment, but inhibited the osmotic swelling by constantly regulating galactose and galactitol concentrations.
Galactan (galactosan) is a polysaccharide consisting of polymerized galactose. In general, galactans in natural sources contain a core of galactose units connected by α(1→3) or α(1→6), with structures containing other monosaccharides as side-chains. Galactan derived from Anogeissus latifolia is primarily α(1→6), but galactan from acacia trees is primarily α(1→3).
Iota-carrageenase () is an enzyme with systematic name iota-carrageenan 4-beta-D-glycanohydrolase (configuration-inverting). This enzyme catalyses the following chemical reaction : Endohydrolysis of (1->4)-beta-D-linkages between D-galactose 4-sulfate and 3,6-anhydro-D-galactose-2-sulfate in iota- carrageenans The main products of hydrolysis are iota-neocarratetraose sulfate and iota-neocarrahexaose sulfate.
Galactosylceramidase (or galactocerebrosidase) is an enzyme that in humans is encoded by the GALC gene. Galactosylceramidase is an enzyme which removes galactose from ceramide derivatives (galactosylceramides). Galactosylceramidase is a lysosomal protein which hydrolyzes the galactose ester bonds of galactosylceramide, galactosylsphingosine, lactosylceramide, and monogalactosyldiglyceride. Mutations in this gene have been associated with Krabbe disease, also known as galactosylceramide lipidosis.
GALT catalyzes the second reaction of the Leloir pathway of galactose metabolism through ping pong bi-bi kinetics with a double displacement mechanism. This means that the net reaction consists of two reactants and two products (see the reaction above) and it proceeds by the following mechanism: the enzyme reacts with one substrate to generate one product and a modified enzyme, which goes on to react with the second substrate to make the second product while regenerating the original enzyme. In the case of GALT, the His166 residue acts as a potent nucleophile to facilitate transfer of a nucleotide between UDP-hexoses and hexose-1-phosphates. #UDP-glucose + E-His Glucose-1-phosphate + E-His-UMP #Galactose-1-phosphate + E-His-UMP UDP-galactose + E-His Two-step action of galactose-1-phosphate uridylyltransferase.
Thus, Oxidation to galactonate serves as an alternate pathway for metabolizing galactose. This oxidative pathway renders accumulated galactonate less harmful than accumulated galactitol.
O-galactose is commonly found on lysine residues in collagen, which often have a hydroxyl group added to form hydroxylysine. Because of this addition of an oxygen, hydroxylysine can then be modified by O-glycosylation. Addition of a galactose to the hydroxyl group is initiated in the endoplasmic reticulum, but occurs predominantly in the Golgi apparatus and only on hydroxylysine residues in a specific sequence. While this O-galactosylation is necessary for correct function in all collagens, it is especially common in collagen types IV and V. In some cases, a glucose sugar can be added to the core galactose.
DTDP-3-amino-3,6-dideoxy-alpha-D-galactopyranose transaminase (, dTDP-6-deoxy- D-xylohex-3-uloseaminase, FdtB, TDP-3-keto-6-deoxy-D- galactose-3-aminotransferase, RavAMT, TDP-3-keto-6-deoxy-D-galactose 3-aminotransferase, TDP-3-dehydro-6-deoxy-D-galactose 3-aminotransferase) is an enzyme with systematic name dTDP-3-amino-3,6-dideoxy-alpha-D- galactopyranose:2-oxoglutarate aminotransferase. This enzyme catalyses the following chemical reaction : dTDP-3-amino-3,6-dideoxy-alpha-D-galactopyranose + 2-oxoglutarate \rightleftharpoons dTDP-3-dehydro-6-deoxy-alpha-D- galactopyranose + L-glutamate This enzyme is a pyridoxal-phosphate protein.
The ABO blood group system is determined by what type of glycosyltransferases are expressed in the body. The ABO gene locus expressing the glycosyltransferases has three main allelic forms: A, B, and O. The A allele encodes 1-3-N-acetylgalactosaminyltransferase that bonds α-N- acetylgalactosamine to D-galactose end of H antigen, producing the A antigen. The B allele encodes 1-3-galactosyltransferase that joins α-D-galactose bonded to D-galactose end of H antigen, creating the B antigen. In case of O allele the exon 6 contains a deletion that results in a loss of enzymatic activity.
The enzyme UDP-glucose 4-epimerase (), also known as UDP-galactose 4-epimerase or GALE, is a homodimeric epimerase found in bacterial, fungal, plant, and mammalian cells. This enzyme performs the final step in the Leloir pathway of galactose metabolism, catalyzing the reversible conversion of UDP-galactose to UDP-glucose. GALE tightly binds nicotinamide adenine dinucleotide (NAD+), a co-factor required for catalytic activity. Additionally, human and some bacterial GALE isoforms reversibly catalyze the formation of UDP-N- acetylgalactosamine (UDP-GalNAc) from UDP-N-acetylglucosamine (UDP-GlcNAc) in the presence of NAD+, an initial step in glycoprotein or glycolipid synthesis.
Xylogalacturonan beta-1,3-xylosyltransferase (, xylogalacturonan xylosyltransferase, XGA xylosyltransferase) is an enzyme with systematic name UDP-D-xylose:xylogalacturonan 3-beta-D-xylosyltransferase. This enzyme catalyses the following chemical reaction : Transfers a xylosyl residue from UDP-D-xylose to a D-galactose residue in xylogalacturonan, forming a beta-1,3-D-xylosyl-D-galactose linkage. This enzyme is involved in plant cell wall synthesis.
Because children with DG develop increased tolerance for dietary galactose as they grow, few healthcare providers recommend dietary restriction of galactose beyond early childhood. A revised perspective on clinical care for infants with Duarte galactosemia was published in 2019.McCandless, S. E., 2019. Answering a Question Older Than Most Pediatricians: What to Do About Duarte Variant Galactosemia. Pediatrics, 143(1). doi: 10.1542/peds.
Kappa-carrageenase (, kappa-carrageenan 4-beta-D-glycanohydrolase) is an enzyme with systematic name kappa-carrageenan 4-beta-D-glycanohydrolase (configuration-retaining). This enzyme catalyses the following chemical reaction : Endohydrolysis of (1->4)-beta-D-linkages between D-galactose 4-sulfate and 3,6-anhydro-D-galactose in kappa-carrageenans The main products of hydrolysis are neocarrabiose-sulfate and neocarratetraose-sulfate.
Galactosamine is a hexosamine derived from galactose with the molecular formula C6H13NO5. This amino sugar is a constituent of some glycoprotein hormones such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Other sugar constituents of FSH and LH include glucosamine, galactose and glucose. Galactosamine is a hepatotoxic, or liver-damaging, agent that is sometimes used in animal models of liver failure.
Origins, distribution and expression of the Duarte-2 (D2) allele of galactose-1-phosphate uridylyltransferase. Hum Mol Genet. 2009 May 1;18(9):1624-32.
N-acetylgalactosamine (GalNAc) can be added to the H-antigen to form the A-antigen. Galactose (Gal) can be added to form the B-antigen.
Parkia bicolor exudes a water-soluble, proteinaceous gum. After hydrolysis, this yields 74% galactose, 9% arabinose, 9.5% glucuronic acid and 7.5% 4-0-methylglucuronic acid.
In vitro and studies show that Candidal growth, adhesion and biofilm formation is enhanced by the presence of carbohydrates such as glucose, galactose and sucrose.
Galactosemia, the inability to metabolize galactose in liver cells, is the most common monogenic disorder of carbohydrate metabolism, affecting 1 in every 55,000 newborns. When galactose in the body is not broken down, it accumulates in tissues. The most common signs are failure to thrive, hepatic insufficiency, cataracts and developmental delay. Long term disabilities include poor growth, mental retardation, and ovarian failure in females.
Both consist of a Gd(III) ion complexed with a tetraazamacrocycle. At the N-10 position, a two-carbon chain links the gadolinium-tertaazamacrocycle complex to a molecule of galactose. The galactose is linked to the complex by a β-glycosidic bond at its C-1 position. The two forms of the contrast agent differ only in the location of a single methyl group.
Galactosemia results from an inability to process galactose, a simple sugar. This deficiency occurs when the gene for galactose-1-phosphate uridylyltransferase (GALT) has any number of mutations, leading to a deficiency in the amount of GALT produced. There are two forms of Galactosemia: classic and Duarte. Duarte galactosemia is generally less severe than classic galactosemia and is caused by a deficiency of galactokinase.
Raffinose is a trisaccharide composed of galactose, glucose, and fructose. It can be found in beans, cabbage, brussels sprouts, broccoli, asparagus, other vegetables, and whole grains. Raffinose can be hydrolyzed to D-galactose and sucrose by the enzyme α-galactosidase (α-GAL), an enzyme not found in the human digestive tract. α-GAL also hydrolyzes other α-galactosides such as stachyose, verbascose, and galactinol, if present.
Several scientists have determined the composition of plant root mucilage using monosaccharide analysis and linkage analysis, showing that Maize (Zea mays) root mucilage contains high levels of galactose, xylose, arabinose, rhamnose, and glucose, and lower levels of uronic acid, mannose, fucose, and glucuronic acid. Wheat (Triticum aestivum) root mucilage also contains high levels of xylose, arabinose, galactose, glucose, and lower levels of rhamnose, glucuronic acid and mannose. Cowpea (Vigna unguiculata) also contains high levels of arabinose, galactose, glucose, fucose, and xylose, and lower levels of rhamnose, mannose, and glucuronic acid. Many other plants have had their root mucilage composition determined using monosaccharide analysis and monosaccharide linkage analysis.
In enzymology, a procollagen galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + procollagen 5-hydroxy-L- lysine \rightleftharpoons UDP + procollagen 5-(D-galactosyloxy)-L-lysine Thus, the two substrates of this enzyme are UDP-galactose and procollagen 5-hydroxy- L-lysine, whereas its two products are UDP and procollagen 5-(D-galactosyloxy)-L-lysine. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:procollagen-5-hydroxy-L-lysine D-galactosyltransferase. Other names in common use include hydroxylysine galactosyltransferase, collagen galactosyltransferase, collagen hydroxylysyl galactosyltransferase, UDP galactose-collagen galactosyltransferase, uridine diphosphogalactose-collagen galactosyltransferase, and UDPgalactose:5-hydroxylysine-collagen galactosyltransferase.
Fructan - A polysaccharide of fructose 3\. Galactan - A polysaccharide of galactose 4\. Araban - A polysaccharide of arabinose 5\. Xylan - A polysaccharide of xylose Champe, Harvey, Ferrier.
In enzymology, a glycoprotein-fucosylgalactoside alpha-N- acetylgalactosaminyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-N-acetyl-D-galactosamine + glycoprotein-alpha-L- fucosyl-(1,2)-D-galactose \rightleftharpoons UDP + glycoprotein-N-acetyl- alpha-D-galactosaminyl-(1,3)-[alpha-L-fucosyl- (1,2)]-D-galactose Thus, the two substrates of this enzyme are UDP-N-acetyl-D-galactosamine and glycoprotein-alpha-L-fucosyl-(1,2)-D-galactose, whereas its 3 products are UDP, glycoprotein-N-acetyl-alpha-D-galactosaminyl-(1,3)-[alpha-L-fucosyl-, and (1,2)]-D-galactose. This enzyme belongs to the family of transferases, specifically those glycosyltransferases hexosyltransferases. The systematic name of this enzyme class is UDP-N-acetyl-D-galactosamine:glycoprotein-alpha- L-fucosyl-(1,2)-D-ga lactose 3-N-acetyl-D-galactosaminyltransferase. Other names in common use include A-transferase, histo-blood group A glycosyltransferase, (Fucalpha1→2Galalpha1→3-N-acetylgalactosaminyltransferase), UDP- GalNAc:Fucalpha1→2Galalpha1→3-N-acetylgalactosaminyltransferase, alpha-3-N-acetylgalactosaminyltransferase, blood-group substance alpha- acetyltransferase, blood-group substance A-dependent acetylgalactosaminyltransferase, fucosylgalactose acetylgalactosaminyltransferase, histo-blood group A acetylgalactosaminyltransferase, histo-blood group A transferase, UDP-N- acetyl-D-galactosamine:alpha-L-fucosyl-1,2-D-galactose, and 3-N-acetyl-D- galactosaminyltransferase.
Galactose mutarotase (aldose 1-epimerase) (gene name GALM) is a human enzyme that converts alpha-aldose to the beta-anomer. It belongs to family of aldose epimerases.
UTP also has the role of a source of energy or an activator of substrates in metabolic reactions, like that of ATP, but more specific. When UTP activates a substrate (like Glucose-1-phosphate), UDP- glucose is formed and inorganic phosphate is released. UDP-glucose enters the synthesis of glycogen. UTP is used in the metabolism of galactose, where the activated form UDP-galactose is converted to UDP-glucose.
Galactocerebrosides are abundant sphingolipids of the myelin membrane of the central nervous system and peripheral nervous system and are also present in small amounts in kidney. The key enzymatic step in the biosynthesis of galactocerebrosides consists of the transfer of galactose to ceramide catalyzed by UDP-galactose ceramide galactosyltransferase (CGT, EC 2.4.1.45). The enzyme encoded by the CGT gene is the first involved in complex lipid biosynthesis in the myelinating oligodendrocyte.
Galactose-alpha-1,3-galactose, commonly known as alpha gal and the Galili antigen, is a carbohydrate found in most mammalian cell membranes. It is not found in primates, including humans, who have lost the GGTA1 gene. Their immune systems recognize it as a foreign body and produce xenoreactive immunoglobulin M antibodies, leading to organ rejection after transplantation. Anti-alpha gal immunoglobulin G antibodies are some of the most common in humans.
To get around this, Hou et al. developed a bumped pro-drug via methylation of the O6 of the galactose moiety of galactosyl-NONOate. They engineered a corresponding hole-modified β-galactosidase mutant, A4-β-GalH363A with specificity for the bumped galactosyl-NONOate. The bumped pro-drug evaded cleavage by wild type β-galactosidase due to the methylated O6 of the galactose moiety and strict regioselectivity of glycosidases.
However, the sugar galactose-alpha-1,3-galactose (αGal) has been implicated as a major factor in hyperacute rejection in xenotransplantation. Unlike virtually all other mammals, humans and other primates do not make αGal, and in fact recognize it as an antigen. During transplantation, xenoreactive natural antibodies recognize αGal on the graft endothelium as an antigen, and the resulting complement-mediated immune response leads to a rejection of the transplant.
UDP-glucose is used in nucleotide sugar metabolism as an activated form of glucose, a substrate for enzymes called glucosyltransferases. UDP-glucose is a precursor of glycogen and can be converted into UDP-galactose and UDP-glucuronic acid, which can then be used as substrates by the enzymes that make polysaccharides containing galactose and glucuronic acid. UDP-glucose can also be used as a precursor of sucrose, lipopolysaccharides and glycosphingolipids.
This lipid region anchors the polymer chain to the cytoplasmic membrane. These lipoteichoic acids resemble the lipopolysaccharides of Gram- negative bacteria in both structure and function, being the only amphipathic polymers at the cell surface. L. monocytogenes has D-galactose residues on its surface that can attach to D-galactose receptors on the host cell walls. These host cells are generally M cells and Peyer's patches of the intestinal mucosa.
Cartoon diagram of a dimer of Escherichia coli galactose-1-phosphate uridylyltransferase (GALT) in complex with UDP-galactose (stick models). Potassium, zinc, and iron ions are visible as purple, gray, and bronze-colored spheres respectively. In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers.
D-Galactose, for comparison Migalastat is used in form of the hydrochloride, which is a white crystalline solid and is soluble in water. The molecule has four asymmetric carbon atoms with the same stereochemistry as the sugar D-galactose, but is missing the first hydroxyl group. It has a nitrogen atom in the ring instead of an oxygen, which makes it an iminosugar. The structure is formally derived from nojirimycin.
Growth was not observed on single sugars or amino acids such as D-glucose, D-galactose, D-fructose, D-xylose, lactose, maltose, sucrose, alanine, glutamate, glycine, and histidine.
In enzymology, a fucosylgalactoside 3-alpha-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + alpha-L- fucosyl-(1->2)-D-galactosyl-R \rightleftharpoons UDP + alpha-D- galactosyl-(1->3)-[alpha-L-fucosyl(1->2)]-D-galactosyl-R Thus, the two substrates of this enzyme are UDP-galactose and alpha-L- fucosyl-(1->2)-D-galactosyl-R, whereas its two products are UDP and alpha-D- galactosyl-(1->3)-[alpha-L-fucosyl(1->2)]-D-galactosyl-R. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:alpha-L- fucosyl-(1->2)-D-galactoside 3-alpha-D-galactosyltransferase. Other names in common use include UDP-galactose:O-alpha-L-fucosyl(1->2)D-galactose, alpha-D- galactosyltransferase, UDPgalactose:glycoprotein-alpha-L- fucosyl-(1,2)-D-galactose, 3-alpha-D-galactosyltransferase, [blood group substance] alpha-galactosyltransferase, blood-group substance B-dependent galactosyltransferase, glycoprotein-fucosylgalactoside alpha- galactosyltransferase, histo-blood group B transferase, and histo-blood substance B-dependent galactosyltransferase.
This motif is the most abundant among all possible motifs made up of three nodes, as is shown in the gene regulatory networks of fly, nematode, and human. The enriched motifs have been proposed to follow convergent evolution, suggesting they are "optimal designs" for certain regulatory purposes. For example, modeling shows that feed-forward loops are able to coordinate the change in node A (in terms of concentration and activity) and the expression dynamics of node C, creating different input- output behaviors. The galactose utilization system of E. coli contains a feed- forward loop which accelerates the activation of galactose utilization operon galETK, potentially facilitating the metabolic transition to galactose when glucose is depleted.
This enzyme participates in 7 metabolic pathways: glycolysis / gluconeogenesis, fructose and mannose metabolism, galactose metabolism, ascorbate and aldarate metabolism, starch and sucrose metabolism, aminosugars metabolism, and phosphotransferase system (pts).
Our understanding of the mechanism of galactose oxidase inspires researchers to develop model compounds that mimics the structure and function of galactose oxidase. It appears that electron- sharing between the copper and the free radical is the crucial element in the success of synthesizing these compounds. The first model compound of GAOX made is [Cu(II)(dnc)], which utilizes duncamine (dnc) as the chelating ligand. Other model compounds have been studied and reported in literature.
Surprisingly, 3C-seq studies did not reveal the physical clustering of rrn operons, contradicting the results of the fluorescence-based study. Therefore, further investigation is required to resolve these contradicting observations. In another example, GalR, forms an interaction network of GalR binding sites that are scattered across the chromosome. GalR is a transcriptional regulator of the galactose regulon composed of genes encoding enzymes for transport and metabolism of the sugar D-galactose.
These enzymes catalyse sialyltransfer reactions during glycosylation, and are type II membrane proteins. There are about twenty different sialyltransferases which can be distinguished on the basis of the acceptor structure on which they act and on the type of sugar linkage they form. For example, a group of sialyltransferases adds sialic acid with an alpha-2,3 linkage to galactose, while other sialyltransferases add sialic acid with an alpha-2,6 linkage to galactose or N-acetylgalactosamine.
Similar to other fungal cell wall polysaccharides, galactosaminogalactan is synthesized by polymerization of nucleotide sugars. Although the actual glycosyltransferase responsible for polymerization has not been reported, the synthesis of precursor nucleotide sugars has been studied. The galactose component originates from UDP-galactose and the GalNAc component originates from UDP-N-acetylgalactosamine. These nucleotide sugars are not physiologically favored and must to be converted from UDP-glucose and Uridine diphosphate N-acetylglucosamine (GlcNAc), respectively.
The UDP-glucose 4-epimerase Uge3 is responsible for these conversions.Lee MJ, Gravelat FN, Cerone RP, Baptista SD, Campoli PV, Choe SI, Kravtsov I, Vinogradov E, Creuzenet C, Liu H, Berghuis AM, Latgé JP, Filler SG, Fontaine T, Sheppard DC. Overlapping and distinct roles of Aspergillus fumigatus UDP-glucose 4-epimerases in galactose metabolism and the synthesis of galactose-containing cell wall polysaccharides. J Biol Chem. 2014 Jan 17;289(3):1243-56.
In enzymology, a glycosaminoglycan galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + glycosaminoglycan \rightleftharpoons UDP + D-galactosylglycosaminoglycan Thus, the two substrates of this enzyme are UDP-galactose and glycosaminoglycan, whereas its two products are UDP and D-galactosylglycosaminoglycan. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:glycosaminoglycan D-galactosyltransferase. This enzyme is also called uridine diphosphogalactose-mucopolysaccharide galactosyltransferase.
Galactoglucomannan is a water-soluble hemicellulose, consisting of galactose, glucose and mannose. Many softwood species, e.g. Norway spruce are rich of galactoglucomannans and can contain it up to 10–20%.
Vacuoles in the tuber of S. affinis are rich in stachyose. Stachyose is a tetrasaccharide, consist out of galactose, glucose and fructose. Stachyose is up to 80-90% in dry tubers.
Antibody ligation of Siglec-F has also been shown to inhibit eosinophil-mediated intestinal inflammation and airway remodeling in OVA challenge models. The ST3Gal-III enzyme is necessary for the generation of the natural Siglec-F ligand, which remains unknown but is induced by IL-4 and IL-13 in the airway. Loss of this enzyme leads to enhanced allergic eosinophilic airway inflammation. Despite evidence that Siglec-F binds specifically to 6′-sulfo-sialyl Lewis X and 6′-sulfated sialyl N-acetyl-D- lactosamine, in which galactose is sulfated at carbon 6, mice deficient in the two known galactose 6-O-sulfotransferases, keratan sulfate galactose 6-O-sulfotransferase (KSGal6ST) and chondroitin 6-O-sulfotransferase 1 (C6ST-1), express equivalent levels of Siglec-F ligand.
In enzymology, a lactosylceramide 4-alpha-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + beta-D- galactosyl-(1->4)-D-glucosylceramide \rightleftharpoons UDP + alpha-D- galactosyl-(1->4)-beta-D-galactosyl-(1->4)-D- glucosylceramide Thus, the two substrates of this enzyme are UDP-galactose and beta-D- galactosyl-(1->4)-D-glucosylceramide, whereas its 3 products are UDP, alpha-D- galactosyl-(1->4)-beta-D-galactosyl-(1->4)-D-, and glucosylceramide. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP- galactose:lactosylceramide 4II-alpha-D-galactosyltransferase. Other names in common use include Galbeta1-4Glcbeta1-Cer alpha1,4-galactosyltransferase, globotriaosylceramide/CD77 synthase, and histo-blood group Pk UDP-galactose.
In enzymology, a sn-glycerol-3-phosphate 2-alpha-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + sn-glycerol 3-phosphate \rightleftharpoons UDP + 2-(alpha-D-galactosyl)-sn-glycerol 3-phosphate Thus, the two substrates of this enzyme are UDP-galactose and sn- glycerol 3-phosphate, whereas its two products are UDP and 2-(alpha-D- galactosyl)-sn-glycerol 3-phosphate. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:sn-glycerol-3-phosphate 2-alpha-D- galactosyltransferase. Other names in common use include floridoside-phosphate synthase, UDP-galactose:sn-glycerol-3-phosphate-2-D-galactosyl transferase, FPS, UDP-galactose, sn-3-glycerol phosphate:1->2' galactosyltransferase, floridoside phosphate synthetase, and floridoside phosphate synthase.
In enzymology, a galactosylxylosylprotein 3-beta-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + 4-beta-D- galactosyl-O-beta-D-xylosylprotein \rightleftharpoons UDP + 3-beta-D- galactosyl-4-beta-D-galactosyl-O-beta-D-xylosylprotein Thus, the two substrates of this enzyme are UDP-galactose and 4-beta-D-galactosyl-O-beta-D- xylosylprotein, whereas its two products are UDP and 3-beta-D- galactosyl-4-beta-D-galactosyl-O-beta-D-xylosylprotein. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:4-beta-D-galactosyl-O- beta-D-xylosylprotein 3-beta-D-galactosyltransferase. Other names in common use include galactosyltransferase II, and uridine diphosphogalactose- galactosylxylose galactosyltransferase.
In enzymology, an indolylacetyl-myo-inositol galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + (indol-3-yl)acetyl-myo-inositol \rightleftharpoons UDP + 5-O-(indol-3-yl)acetyl-myo-inositol D-galactoside Thus, the two substrates of this enzyme are UDP-galactose and indol-3-ylacetyl-myo-inositol, whereas its two products are UDP and 5-O-(indol-3-yl)acetyl-myo-inositol D-galactoside. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP- galactose:(indol-3-yl)acetyl-myo-inositol 5-O-D-galactosyltransferase. Other names in common use include uridine diphosphogalactose-indolylacetylinositol, galactosyltransferase, indol-3-ylacetyl-myo-inositol galactoside synthase, UDP-galactose:indol-3-ylacetyl-myo-inositol, and 5-O-D-galactosyltransferase.
Beta-1,4-galactosyltransferase 4 is an enzyme that in humans is encoded by the B4GALT4 gene. This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures.
Beta-1,4-galactosyltransferase 3 is an enzyme that in humans is encoded by the B4GALT3 gene. This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures.
Beta-1,4-galactosyltransferase 2 is an enzyme that in humans is encoded by the B4GALT2 gene. This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures.
Beta-1,4-galactosyltransferase 5 is an enzyme that in humans is encoded by the B4GALT5 gene. This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures.
This charge stabilization can cause any potential concerted pathway to become asynchronous and approaches intermediates with oxocarbenium character of the SN1 mechanism for glycosylation. Reaction scheme for thiourea catalyzed glycosylation of galactose 13C kinetic isotope effect measurements for thiourea catalyzed glycosylation of galactose Jacobsen and coworkers observed small normal KIE's at C1, C2, and C5 which suggests significant oxocarbenium character in the transition state and an asynchronous reaction mechanism with a large degree of charge separation.
Galactokinase from S. cerevisiae, on the other hand, is highly specific for D-galactose and cannot phosphorylate glucose, mannose, arabinose, fucose, lactose, galactitol, or 2-deoxy-D-galactose. Moreover, the kinetic properties of galactokinase also differ across species. The sugar specificity of galactokinases from different sources has been dramatically expanded through directed evolution and structure-based protein engineering. The corresponding broadly permissive sugar anomeric kinases serve as a cornerstone for in vitro and in vivo glycorandomization.
Beta-1,4-galactosyltransferase 1 is an enzyme that in humans is encoded by the B4GALT1 gene. This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures.
In enzymology, a kaempferol 3-O-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + kaempferol \rightleftharpoons UDP + kaempferol 3-O-beta-D-galactoside Thus, the two substrates of this enzyme are UDP-galactose and kaempferol, whereas its two products are UDP and trifolin. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:kaempferol 3-O-beta-D-galactosyltransferase. This enzyme is also called F3GalTase.
N. sinuspersici sp. nov has been observed to utilize carbon sources including d-Galactose , lactose, melibiose, glycerol, sucrose, maltose, mannitol, d-mannose, l-rhamnose, d-xylose, inulin, citrate, malonate, pyruvate, and propionate.
J Lab Clin Med 1964;64:695-705.Beutler E, Mitchell M. New rapid for the estimation of red cell galactose-1-phosphate uridyl transferase activity. J Lab Clin Med 1968;72:527-532.
Galactogen is a polysaccharide of galactose that functions as energy storage in pulmonate snails and some Caenogastropoda. Goudsmit, E.M. (1972). Carbohydrates and carbohydrate metabolism in Mollusca. In: Florkin, M. and Scheer, B.T. eds.
A feature that distinguishes E. jeanselmei from Cladosporium which forms very similar colonies is that E. jeanselmei is not proteolytic. It is able to assimilate glucose, galactose, maltose, and sucrose, but not lactose.
This cross-linked tyrosinate is also a free radical. In the fully oxidized form of galactose oxidase, the free radical couples to the copper(II) center antiferromagnetically, supported by EPR spectroscopic studies. Moreover, the formation of cross-linking thioether bond is believed to lower the oxidation potential of Tyr272 phenoxide, making this phenoxyl more easily oxidized to form the radical in post-translational modification. The free radical in galactose oxidase is unusually stable compared to many other protein free radicals.
In the second step, degalactosylation, the covalent bond is broken when Glu461 accepts a proton, replacing the galactose with water. Two transition states occur in the deep site of the enzyme during the reaction, once after each step. When water participates in the reaction, galactose is formed, otherwise, when D-glucose acts as the acceptor in the second step, transgalactosylation occurs . It has been kinetically measured that single tetramers of the protein catalyze reactions at a rate of 38,500 ± 900 reactions per minute.
Beta-1,3-galactosyltransferase 4 is an enzyme that in humans is encoded by the B3GALT4 gene. This gene is a member of the beta-1,3-galactosyltransferase (beta3GalT) gene family. This family encodes type II membrane-bound glycoproteins with diverse enzymatic functions using different donor substrates (UDP-galactose and UDP-N-acetylglucosamine) and different acceptor sugars (N-acetylglucosamine, galactose, N-acetylgalactosamine). The beta3GalT genes are distantly related to the Drosophila Brainiac gene and have the protein coding sequence contained in a single exon.
Beta-D-galactosyl-(1->4)-L-rhamnose phosphorylase (, D-galactosyl- beta1->4-L-rhamnose phosphorylase, GalRhaP) is an enzyme with systematic name beta-D-galactosyl-(1->4)-L-rhamnose:phosphate 1-alpha-D-galactosyltransferase. This enzyme catalyses the following chemical reaction : beta-D- galactosyl-(1->4)-L-rhamnose + phosphate \rightleftharpoons L-rhamnose + alpha-D-galactose 1-phosphate The enzyme from Clostridium phytofermentans is also active towards beta-D-galactosyl derivatives of L-mannose, L-lyxose, D-glucose, 2-deoxy-D-glucose, and D-galactose.
In addition, the strong environmental protection response of B. cenocepacia is attributed to the biofilm formed by groups of the organism. This biofilm contains exopolysaccharides (abbreviated EPS) that strengthen the bacterium's resistance to antibiotics. It is made up of a highly branched polysaccharide unit with one glucose, one glucuronic acid, one mannose, one rhamnose, and three galactose molecules. This species in the Bcc has also created another polysaccharide with one 3-deoxy-d-manno-2-octulosonic acid and three galactose molecules.
Beta-1,3-galactosyltransferase 5 is an enzyme that in humans is encoded by the B3GALT5 gene. This gene is a member of the beta-1,3-galactosyltransferase (beta3GalT) gene family. This family encodes type II membrane-bound glycoproteins with diverse enzymatic functions using different donor substrates (UDP-galactose and UDP-N-acetylglucosamine) and different acceptor sugars (N-acetylglucosamine, galactose, N-acetylgalactosamine). The beta3GalT genes are distantly related to the Drosophila Brainiac gene and have the protein coding sequence contained in a single exon.
Galactosemia, a rare metabolic disorder characterized by decreased ability to metabolize galactose, can be caused by a mutation in any of the three enzymes in the Leloir pathway. Galactokinase deficiency, also known as galactosemia type II, is a recessive metabolic disorder caused by a mutation in human galactokinase. About 20 mutations have been identified that cause galactosemia type II, the main symptom of which is early onset cataracts. In lens cells of the human eye, aldose reductase converts galactose to galactitol.
The bite of the lone star tick can cause a person to develop alpha-gal meat allergy, a delayed response to nonprimate mammalian meat and meat products. The allergy manifests as anaphylaxis — a life-threatening allergic reaction characterized by constriction of airways and a drop in blood pressure. This response is triggered by an IgE antibody to the mammalian oligosaccharide galactose-alpha-1,3-galactose (alpha-gal). A study published in 2019 discovered alpha-gal in the saliva of the lone star tick.
Guar gum is more soluble than locust bean gum due to its extra galactose branch points. Unlike locust bean gum, it is not self-gelling.Martin Chaplin "Water Structure and Behavior: Guar Gum". April 2012.
Lactose is a disaccharide. It is a sugar composed of galactose and glucose subunits and has the molecular formula C12H22O11. Lactose makes up around 2–8% of milk (by weight). The name comes from ' (gen.
Galactose is bound in the center of the core, occluded from the outside solutions by hydrophobic residues. The architecture of the core is similar to that of the leucine transporter (LeuT) (TC# 2.A.22.4.
Fungal growth can be supported by D-glucose, D-mannose, D-xylose, L-sorbose, D-fructose, D-galactose, sucrose, D-mannitol, SorbitolD-sorbital, ethanol and glycerol. Sporulation often requires a balance of carbon and nitrogen.
The penultimate sugar is galactose and the terminal sugar is sialic acid, as the sugar backbone is modified in the Golgi apparatus. Sialic acid carries a negative charge, providing an external barrier to charged particles.
The gum contains 5.4% ash, 0.98% N, 1.49% methoxyl, and by calculation, 32.2% uronic acid. The sugar composition after hydrolysis: 9.0% 4-0-methylglucuronic acid, 23.2% glucuronic acid, 56% galactose, 10% arabinose, and 2% rhamnose.
By contrast, a glucagon challenge test after a meal causes hyperglycemia, with increased levels of plasma lactate and alanine. Oral loading of glucose, galactose, or fructose results in a marked rise in blood lactate levels.
These adhesins specifically bind D-galactose-D-galactose moieties on the P blood-group antigen of erythrocytes and uroepithelial cells. Approximately 1% of the human population lacks this receptor, and its presence or absence dictates an individual's susceptibility or non-susceptibility, respectively, to E. coli urinary tract infections. Uropathogenic E. coli produce alpha- and beta-hemolysins, which cause lysis of urinary tract cells. Another virulence factor commonly present in UPEC is the Dr family of adhesins, which are particularly associated with cystitis and pregnancy-associated pyelonephritis.
Infants with DG often show biochemical differences from infants who do not have DG, especially if exposed to milk, but may not show any acute or developmental symptoms. Specifically, when exposed to high levels of dietary galactose, a sugar abundant in breast milk, milk formula, and most dairy products,Van Calcar SC, Bernstein LE, Rohr FJ, Scaman CH, Yannicelli S, Berry GT. A re- evaluation of life-long severe galactose restriction for the nutrition management of classic galactosemia. Mol Genet Metab. 2014 Jul;112(3):191-7.
UDP-GalNAc:beta-1,3-N-acetylgalactosaminyltransferase 1 is an enzyme that in humans is encoded by the B3GALNT1 gene. This gene is a member of the beta-1,3-galactosyltransferase (beta3GalT) gene family. This family encodes type II membrane-bound glycoproteins with diverse enzymatic functions using different donor substrates (UDP-galactose and UDP-N-acetylgalactosamine) and different acceptor sugars (N-acetylglucosamine, galactose, N-acetylgalactosamine). The beta3GalT genes are distantly related to the Drosophila Brainiac gene and have the protein coding sequence contained in a single exon.
Lactose is a disaccharide sugar composed of galactose and glucose that is found in milk. Lactose can not be absorbed by the intestine and needs to be split in the small intestine into galactose and glucose by the enzyme called lactase; unabsorbed lactose can cause abdominal pain, bloating, diarrhea, gas, and nausea. In most mammals, production of lactase diminishes after infants are weaned from maternal milk. However, 5% to 90% of the human population possess an advantageous autosomal mutation in which lactase production persists after infancy.
Hydrolysis of the disaccharide lactose to glucose and galactose Milk allergy is distinct from lactose intolerance, which is a nonallergic food sensitivity, due to the lack of the enzyme lactase in the small intestines to break lactose down into glucose and galactose. The unabsorbed lactose reaches the large intestine, where resident bacteria use it for fuel, releasing hydrogen, carbon dioxide and methane gases. These gases are the cause of abdominal pain and other symptoms. Lactose intolerance does not cause damage to the gastrointestinal tract.
More recently, pooled analysis done by the Harvard School of Public Health showed no specific correlation between lactose-containing foods and ovarian cancer, and showed statistically insignificant increases in risk for consumption of lactose at 30 g/day. More research is necessary to ascertain possible risks. Some ongoing studies suggest galactose may have a role in treatment of focal segmental glomerulosclerosis (a kidney disease resulting in kidney failure and proteinuria). This effect is likely to be a result of binding of galactose to FSGS factor.
Furthermore, animal cells can also produce glycoproteins containing the galactose-alpha-1,3-galactose epitope, which can induce serious allergenic reactions, including anaphylactic shock, in people who have Alpha-gal allergy. These drawbacks have been addressed by several approaches such as eliminating the pathways that produce these glycan structures through genetic knockouts. Furthermore, other expression systems have been genetically engineered to produce therapeutic glycoproteins with human-like N-linked glycans. These include yeasts such as Pichia pastoris, insect cell lines, green plants, and even bacteria.
GALE inverts the configuration of the 4' hydroxyl group of UDP- galactose through a series of 4 steps. Upon binding UDP-galactose, a conserved tyrosine residue in the active site abstracts a proton from the 4' hydroxyl group. Concomitantly, the 4' hydride is added to the si-face of NAD+, generating NADH and a 4-ketopyranose intermediate. The 4-ketopyranose intermediate rotates 180° about the pyrophosphoryl linkage between the glycosyl oxygen and β-phosphorus atom, presenting the opposite face of the ketopyranose intermediate to NADH.
Rhamnogalacturonan-II (RG-II) is a complex polysaccharide termed a pectin that is found in the primary walls of dicotyledenous and monocotyledenous plants and gymnosperms. RG-II is also likely to be present in the walls of some lower plants (ferns, horsetails, and lycopods). Its structure is conserved across vascular plants. RG-II is composed of 12 different glycosyl residues including D-rhamnose, apiose, D-galactose, L-galactose, Kdo, galacturonic acid, L-arabinose, xylose, and L-aceric acid, linked together by at least 21 distinct glycosidic linkages.
The IA and IB alleles produce different modifications. The enzyme coded for by IA adds an N-acetylgalactosamine to a membrane-bound H antigen. The IB enzyme adds a galactose. The i allele produces no modification.
It has been shown that a single change in the stereochemistry at C4 carbon shifts preference for aromatic residues from \beta side (2.7 fold preference for glucose) to the \alpha side (14 fold preference for galactose).
30 wt. %), whereas tender stem tips exhibit a low cellulose content (9.2 wt. %). Salicornia brachiata revealed the dominance of rhamnose, arabinose, mannose, galactose, and glucose, with meager presence of ribose and xylose in their structural polysaccharide.
Because 90% of filtered glucose is reabsorbed through SGLT-2, research has focused specifically on SGLT-2. Inhibition of SGLT-1 may also lead to the genetic disease glucose-galactose malabsorption, which is characterized by severe diarrhea.
Weak growth is seen at but is absent at higher temperatures. T. asteroides can be distinguish with other relative species in the genus Trichosporon by its ability to utilize D-galactose, L-rhamnose, erythritol and L-arabinitol.
Although they may be structurally similar, they all have different functions. Beta-gal is inhibited by L-ribose, non-competitive inhibitor iodine, and competitive inhibitors phenylthyl thio-beta-D-galactoside (PETG), D-galactonolactone, isopropyl thio-beta-D-galactoside (IPTG), and galactose. β-galactosidase is important for organisms as it is a key provider in the production of energy and a source of carbons through the break down of lactose to galactose and glucose. It is also important for the lactose intolerant community as it is responsible for making lactose-free milk and other dairy products.
A poly-N-acetyllactosamine structure can be formed by the alternating addition of GlcNAc and galactose sugars onto the GalNAc sugar. Terminal sugars on O-glycans are important in recognition by lectins and play a key role in the immune system. Addition of fucose sugars by fucosyltransferases forms Lewis epitopes and the scaffold for blood group determinants. Addition of a fucose alone creates the H-antigen, present in people with blood type O. By adding a galactose onto this structure, the B-antigen of blood group B is created.
Galactose-3-O-sulfotransferase 2 is an enzyme that in humans is encoded by the GAL3ST2 gene. This gene encodes a member of the galactose-3-O-sulfotransferase protein family. The product of this gene catalyzes sulfonation by transferring a sulfate group to the hydroxyl at C-3 of nonreducing beta-galactosyl residues, and it can act on both type 1 and type 2 (Galbeta 1-3/1-4GlcNAc-R) oligosaccharides with similar efficiencies, and on core 1 glycans. This enzyme has been implicated in tumor metastasis processes.
The disease has symptoms that consist of watery and/or acidic diarrhea which is the result of water retention in the intestinal lumen and osmotic loss created by non-absorbed glucose, galactose and sodium. Glucose-Galactose malabsorption can cause death due to loss of water from diarrhea if the disease is not treated. To counteract the disease and the effects of acute diarrhea and dehydration, the sodium glucose cotransporter 1 protein is targeted for its mechanistic benefits with ion transfers by oral rehydration therapy through increasing sodium, glucose, and water concentrations for intestinal reabsorption.
In order to modify the mechanical properties of agarose to reproduce the natural environment of other human cells, agarose can be chemically modified through the precise oxidation of the primary alcohol of the D-galactose into carboxylic acid. This chemical modification provides a novel class of materials named carboxylated agarose. Through the control over the number of carboxylated D-galactose on the polysaccharide backbone, the mechanical properties of the resulting hydrogel can be precisely controlled. These carboxylated agarose hydrogels can be then covalently bond to peptides to form hydrogel on which cells can adhere.
Pectin is the soluble polymeric material in the pulp of oranges, which contains 75% of carboxyl of arabinose and galactose. Pectic compounds are complex heteropolysaccharides in that their chemical composition includes a chain structure of axial-axial α-1.4-linked d-galacturonic acid unit along with blocks of L-rhamnose regions that have side chains of arabinose, galactose, and xylose. Pectin methyl-esterase is the enzyme responsible for hydrolyzing carboxymethyl esters and liberating free carboxyl groups and methyl alcohols. The free carboxyl groups interact with cations to form insoluble pectic acid divalent metal ion complexes.
It was not until the late 20th century when DNA looping was correlated with gene expression. For example, in 1990, Mandal and colleagues showed the importance of DNA looping in repressing the galactose and lactose operons in E coli. In the presence of galactose or lactose, repressor proteins form protein-protein and protein-DNA interactions to loop the DNA. This in turn connects the gene promoters with upstream and downstream operators, effectively repressing gene expression by blocking transcription preinitiation complex (PIC) assembly at the promoter and therefore preventing transcription initiation.
In enzymology, a sucrose 6F-alpha-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + sucrose \rightleftharpoons UDP + 6F-alpha-D-galactosylsucrose Thus, the two substrates of this enzyme are UDP-galactose and sucrose, whereas its two products are UDP and 6F-alpha-D- galactosylsucrose. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:sucrose 6F-alpha-D-galactosyltransferase. Other names in common use include uridine diphosphogalactose-sucrose 6F-alpha- galactosyltransferase, UDPgalactose:sucrose 6fru-alpha-galactosyltransferase, and sucrose 6F-alpha-galactotransferase.
In enzymology, a galactogen 6beta-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + galactogen \rightleftharpoons UDP + 1,6-beta-D-galactosylgalactogen Thus, the two substrates of this enzyme are UDP-galactose and galactogen, whereas its two products are UDP and 1,6-beta-D-galactosylgalactogen. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:galactogen beta-1,6-D-galactosyltransferase. Other names in common use include uridine diphosphogalactose-galactogen galactosyltransferase, 1,6-D-galactosyltransferase, and beta-(1-6)-D-galactosyltransferase.
This gene is different from the GAL3ST3 gene located on chromosome 11, which has also been referred to as GAL3ST2 and encodes a related enzyme with distinct tissue distribution and substrate specificities, compared to galactose-3-O-sulfotransferase 2.
The structure of galactose oxidase reveals that the repeated Kelch sequence motif corresponds to a 4-stranded anti-parallel beta-sheet motif that forms the repeat unit in a super-barrel structural fold commonly known as a beta propeller.
Additionally, since the metabolism of galactose in the cell is involved in both anabolic and catabolic pathways, a novel regulatory system using two promoters for differential repression has been identified and characterized within the context of the gal operon.
As galactose is not being catabolized to glucose due to a galactokinase mutation, galactitol accumulates. This galactitol gradient across the lens cell membrane triggers the osmotic uptake of water, and the swelling and eventual apoptosis of lens cells ensues.
The linker is composed of four saccharides, first one being xylose, which is an unusual sugar in a unique place, attached to serine of the protein core and sequentially followed by two galactose and a β-D-glucuronic acid [1, 12].
If terminal sialic acid residues are removed from glycoproteins, the resulting proteins are known as asialoglycoproteins. The exposure of the subterminal galactose residues results in rapid clearance of the glycoproteins from the circulation through hepatocyte asialoglycoprotein receptors on Kuppfer cells.
Finally, sulfation of the polymer occurs at the 6-position of both sugar residues. The enzyme KS-Gal6ST (CHST1) transfers sulfate groups to galactose while N-acetylglucosaminyl-6-sulfotransferase (GlcNAc6ST) (CHST2) transfers sulfate groups to terminal GlcNAc in keratan sulfate.
Lactobionic acid (4-O-β-galactopyranosyl-D-gluconic acid) is a sugar acid. It is a disaccharide formed from gluconic acid and galactose. It can be formed by oxidation of lactose. The carboxylate anion of lactobionic acid is known as lactobionate.
C. violaceum ferments glucose, trehalose, N-acetylglucosamine and gluconate but not L-arabinose, D-galactose, or D-maltose. It is positive for catalase and oxidase reactions. Bacterial isolates in many cases can show high level resistance to a range of antibiotics.
However, in each case, galactose is essential for binding. Crystallisation experiments of galectins in complex with N-acetyllactosamine show that binding arises due to hydrogen bonding interactions from the carbon-4 and carbon-6 hydroxyl groups of galactose and carbon-3 of N-acetylglucosamine (GlcNAc) to the side chains of amino acids in the protein. They cannot bind to other sugars such as mannose because this sugar will not fit inside the carbohydrate recognition domain without steric hindrance. Due to the nature of the binding pocket, galectins can bind terminal sugars or internal sugars within a glycan.
Humans and higher primates also produce "natural antibodies" that are present in serum before viral infection. Natural antibodies have been defined as antibodies that are produced without any previous infection, vaccination, other foreign antigen exposure or passive immunization. These antibodies can activate the classical complement pathway leading to lysis of enveloped virus particles long before the adaptive immune response is activated. Many natural antibodies are directed against the disaccharide galactose α(1,3)-galactose (α-Gal), which is found as a terminal sugar on glycosylated cell surface proteins, and generated in response to production of this sugar by bacteria contained in the human gut.
Due to the polysaccharides in the cell walls, F. lumbricalis is grouped with other commercially important carrageenophytes (red algae that produce carrageenans). From F. lumbricalis a polysaccharide called furcellaran (hybrid β/κ-carrageenan) can be extracted. Furcellaran is non- stoichometrically undersulphated κ-carrageenan, where every 3rd or 4th 3-linked-β-galactose monomer possesses a sulphate ester group at the 4th carbon position. For comparison, an ideal κ-carrageenan molecule would have a sulphate ester group at the 4th carbon in every 3-linked-β-galactose monomer. Furcellaran’s physical properties (gel strengths, gelling and melting temperatures) are similar to κ-carrageenan.
Alpha-gal allergy, also known as mammalian meat allergy (MMA),Catalyst (ABC-TV program) first aired 8 November 2016 is a reaction to galactose- alpha-1,3-galactose (alpha-gal), whereby the body is overloaded with immunoglobulin E (IgE) antibodies on contact with the carbohydrate. Anti-gal is a human natural antibody that interacts specifically with the mammalian carbohydrate structure gal alpha 1-3Gal beta 1-4GlcNAc-R, termed, the alpha- galactosyl epitope. The alpha-gal molecule is found in all mammals except apes, humans, and Old World monkeys. Bites from certain ticks, such as the lone star tick (Am.
In enzymology, a lipopolysaccharide 3-alpha-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + lipopolysaccharide \rightleftharpoons UDP + 3-alpha-D- galactosyl-[lipopolysaccharide glucose] Thus, the two substrates of this enzyme are UDP-galactose and lipopolysaccharide, whereas its two products are UDP and 3-alpha-D-galactosyl-[lipopolysaccharide glucose]. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:lipopolysaccharide 3-alpha-D-galactosyltransferase. Other names in common use include UDP- galactose:lipopolysaccharide alpha,3-galactosyltransferase, UDP- galactose:polysaccharide galactosyltransferase, uridine diphosphate galactose:lipopolysaccharide, alpha-3-galactosyltransferase, uridine diphosphogalactose-lipopolysaccharide, and alpha,3-galactosyltransferase.
In enzymology, a sphingosine beta-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + sphingosine \rightleftharpoons UDP + psychosine Thus, the two substrates of this enzyme are UDP-galactose and sphingosine, whereas its two products are UDP and psychosine. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:sphingosine 1-beta-galactosyltransferase. Other names in common use include psychosine-UDP galactosyltransferase, galactosyl- sphingosine transferase, psychosine-uridine diphosphate galactosyltransferase, UDP-galactose:sphingosine O-galactosyl transferase, uridine diphosphogalactose-sphingosine beta-galactosyltransferase, and UDP- galactose:sphingosine 1-beta-galactotransferase.
Its peptidoglycan consists of the amino acids lysine, alanine, and glutamic acid in the respective ratios: 1.0:4.9:1.0. Cell wall sugars consist of galactose and glucose. The main fatty acids determined in this organism include 12-methyltetradecanoic acid and 14-methylhexadecanoic acid.
Accumulation of galactitol has been attributed to many of the negative effects of galactosemia, and high concentrations of galactitol have been found in people with classic galactosemia (GALT deficiency or Galactose-1-phosphate uridylyltransferase deficiency), galactokinase deficiency, and epimerase deficiency with glucose.
Cis cisterna are associated with the removal of mannose residues. Removal of mannose residues and addition of N-acetylglucosamine occur in medial cisternae. Addition of galactose and sialic acid occurs in the trans cisternae. Sulfation of tyrosines and carbohydrates occurs within the TGN.
Staphylococcus sciuri is a Gram-positive, oxidase-positive, coagulase-negative member of the bacterial genus Staphylococcus consisting of clustered cocci. The type subspecies S. sciuri subsp. sciuri was originally used to categorize 35 strains shown to use cellobiose, galactose, sucrose, and glycerol.
Buehler, Calvin A., B. Ch. E., M. Sc. The Oxidation of Lactose, Glucose, and Galactose by Means of Neutral and Alkaline Potassium Permanganate. Diss. The Ohio State University, 1922. Columbus: Ohio State University, 1922. Print. In 1937, Calvin Buehler married Grace Stone Buehler.
E. coli galactose-1-phosphate uridyltransferase. A deficiency of the human isoform of this transferase causes of galactosemia. Transferase deficiencies are at the root of many common illnesses. The most common result of a transferase deficiency is a buildup of a cellular product.
Structure of galactoglucomannan Galactoglucomannan consists of a backbone of randomly distributed (1→4)-linked mannose and glucose units with (1→6)-linked galactose units attached to mannose units. The hydroxyl groups in locations C2 and C3 in mannose are partially substituted by acetyl groups.
This process is unusual and requires specific xylosyltransferases. Keratan sulphate attaches to a serine or threonine residue through GalNAc, and is extended with two galactose sugars, followed by repeating units of glucuronic acid (GlcA) and GlcNAc. Type II keratan sulphate is especially common in cartilage.
General chemical structure of a monogalactosyl diacylglycerol (MGDG), a prevalent type of galactolipid. R1 and R2 are fatty chains. Galactolipids are a type of glycolipid whose sugar group is galactose. They differ from glycosphingolipids in that they do not have nitrogen in their composition.
Galactose is found in dairy products, avocados, sugar beets, other gums and mucilages. It is also synthesized by the body, where it forms part of glycolipids and glycoproteins in several tissues; and is a by-product from the third-generation ethanol production process (from macroalgae).
From many of the rhamnose residues, sidechains of various neutral sugars branch off. The neutral sugars are mainly D-galactose, L-arabinose and D-xylose, with the types and proportions of neutral sugars varying with the origin of pectin.RG-I. Ccrc.uga.edu. Retrieved 2012-07-16.
Cross-linking by thrombin and stabilization by activated factor XIII Fibrin from different animal sources is generally glycosylated with complex type biantennary asparagine- linked glycans. Variety is found in the degree of core fucosylation and in the type of sialic acid and galactose linkage.
Maj MC, Singh B, Gupta RS: Pentavalent ions dependency is a conserved property of adenosine kinase from diverse sources: identification of a novel motif implicated in phosphate and magnesium ion binding and substrate inhibition. Biochemistry 2002, 41: 4059-4069. This enzyme participates in galactose metabolism.
C. aquaticus reproduces through bipolar mypodial budding. This species is somewhat unusual in the Cryptococcus family in that it can weakly ferment D-glucose, D-galactose, maltose and melezitose. This species is DBB+. C. aquaticus has been studied because of its ability to produce pecticase.
In enzymology, a N-acetylgalactosamine-6-sulfatase () is an enzyme that catalyzes the chemical reaction of cleaving off the 6-sulfate groups of the N-acetyl-D-galactosamine 6-sulfate units of the macromolecule chondroitin sulfate and, similarly, of the D-galactose 6-sulfate units of the macromolecule keratan sulfate. This enzyme belongs to the family of hydrolases, specifically those acting on sulfuric ester bonds. The systematic name of this enzyme class is N-acetyl-D-galactosamine-6-sulfate 6-sulfohydrolase. Other names in common use include chondroitin sulfatase, chondroitinase, galactose-6-sulfate sulfatase, acetylgalactosamine 6-sulfatase, N-acetylgalactosamine-6-sulfate sulfatase, and N-acetylgalactosamine 6-sulfatase.
Sulfatide was the first sulfoglycolipid to be isolated in the human brain. It was named sulfatide in 1884 by Johann Ludwig Wilhelm Thudichum when he published "A Treatist of the Chemical Constitution of the Brain". Originally, in 1933, it was first reported by Blix that sulfatide contained amide bound fatty acid and 4-sphingenine and that the sulfate of sulfatide was thought to be attached to the C6 position of galactose. This was again supported in 1955 by Thannhauser and Schmidt; however, through gas-liquid chromatography, Tamio Yamakawa found that sulfate was actually attached to the C3 position of galactose, not the C6 position.
A 6-phospho-beta-galactosidase () is an enzyme that catalyzes this chemical reaction: :a 6-phospho-beta-D-galactoside + H2O \rightleftharpoons 6-phospho- D-galactose + an alcohol Thus, the two substrates of this enzyme are 6-phospho-beta-D-galactoside and H2O, whereas its two products are 6-phospho- D-galactose and alcohol. This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name of this enzyme class is 6-phospho-beta-D-galactoside 6-phosphogalactohydrolase. Other names in common use include phospho-beta- galactosidase, beta-D-phosphogalactoside galactohydrolase, phospho-beta-D- galactosidase, and 6-phospho-beta-D-galactosidase.
In enzymology, a galactosylgalactosylglucosylceramidase () is an enzyme that catalyzes the chemical reaction :D-galactosyl-D-galactosyl-D-glucosyl-N- acylsphingosine + H2O \rightleftharpoons D-galactose + lactosyl-N- acylsphingosine Thus, the two substrates of this enzyme are D-galactosyl-D- galactosyl-D-glucosyl-N-acylsphingosine and H2O, whereas its two products are D-galactose and lactosyl-N-acylsphingosine. This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name of this enzyme class is D-galactosyl-D-galactosyl-D-glucosyl-N-acylsphingosine galactohydrolase. Other names in common use include trihexosyl ceramide galactosidase, ceramide trihexosidase, ceramidetrihexoside alpha-galactosidase, trihexosylceramide alpha-galactosidase, and ceramidetrihexosidase.
The observation that A. salmonicida contains the spf gene (which encodes Spot 42), but lacks the galK operon (the natural Spot 42 target in E. coli), have inspired scientists to study the role of Spot 42 in this fish pathogen. A. salmonicida is unable to utilize galactose (lacks gal operon) in minimal medium and addition of galactose has little effect on the growth rate. When cells are grown in glucose the level of Spot42 is increased 16–40 folds, but is in contrast decreased 3 folds when cAMP is added, indicating that Spot42 probably have similar roles as in E. coli (i.e., in carbohydrate metabolism).
In enzymology, a xylosylprotein 4-beta-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + O-beta-D-xylosylprotein \rightleftharpoons UDP + 4-beta-D-galactosyl-O-beta-D-xylosylprotein Thus, the two substrates of this enzyme are UDP-galactose and O-beta-D-xylosylprotein, whereas its two products are UDP and 4-beta-D-galactosyl-O-beta-D- xylosylprotein. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:O-beta-D-xylosylprotein 4-beta-D-galactosyltransferase. Other names in common use include UDP-D-galactose:D-xylose galactosyltransferase, UDP-D-galactose:xylose galactosyltransferase, galactosyltransferase I, and uridine diphosphogalactose-xylose galactosyltransferase.
In enzymology, a glycoprotein-N-acetylgalactosamine 3-beta- galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + glycoprotein N-acetyl-D-galactosamine \rightleftharpoons UDP + glycoprotein D-galactosyl-1,3-N-acetyl-D-galactosamine Thus, the two substrates of this enzyme are UDP-galactose and glycoprotein N-acetyl-D- galactosamine, whereas its two products are UDP and glycoprotein D-galactosyl-1,3-N-acetyl-D-galactosamine. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:glycoprotein-N-acetyl-D- galactosamine 3-beta-D-galactosyltransferase. This enzyme is also called uridine diphosphogalactose-mucin beta-(1->3)-galactosyltransferase.
Glucose is added onto ceramide from its precursor in the endoplasmic reticulum, before further modifications occur in the Golgi apparatus. Galactose, on the other hand, is added to ceramide already in the Golgi apparatus, where the galactosphingolipid formed is often sulfated by addition of sulfate groups.
Xyloglucan has a backbone of β1→4-linked glucose residues, most of which are substituted with 1-6 linked xylose sidechains. The xylose residues are often capped with a galactose residue sometimes followed by a fucose residue. The specific structure of xyloglucan differs between plant families.
Beta-galactofuranosidase (, exo-beta-galactofuranosidase, exo-beta-D- galactofuranosidase, beta-D-galactofuranosidase) is an enzyme with systematic name beta-D-galactofuranoside hydrolase. This enzyme catalyses the following chemical reaction : Hydrolysis of terminal non-reducing beta-D- galactofuranosides, releasing [galactose] The enzyme from Helminthosporium sacchari detoxifies helminthosporoside.
Cerebroside-sulfatase (, arylsulfatase A, cerebroside sulfate sulfatase) is an enzyme with systematic name cerebroside-3-sulfate 3-sulfohydrolase. This enzyme catalyses the following chemical reaction : a cerebroside 3-sulfate + H2O \rightleftharpoons a cerebroside + sulfate This enzyme hydrolyses galactose-3-sulfate residues in a number of lipids.
Other oxidized forms of -galactose are -galactonic acid (carboxylic group at C1) and meso-galactaric acid (mucic acid) (carboxylic groups at C1 and C6). It is also a uronic acid or hexuronic acid. Naturally occurring uronic acids are -glucuronic acid, -galacturonic acid, -iduronic acid and -mannuronic acid.
Cryptococcus terreus is a fungus species. It is unique within its genus because it can use glucose, lactose, galactose and potassium nitrate. The cells are oval in shape with mucous capsules. The culture when grown start of cream color but turned tan with a “tough” surface skin.
The seeds of the guar bean contain a large endosperm. This endosperm consists of a large polysaccharide of galactose and mannose. This polymer is water-soluble and exhibits a viscosifying effect in water. Guar gum has a multitude of different applications in food products, industrial products, and extractive industry.
The motif is also found in mouse protein MIPP and in a number of poxviruses. In addition, kelch repeats have been recognised in alpha- and beta-scruin, in galactose oxidase from the fungus Dactylium dendroides and in the Escherichia coli NanM protein, that is a sialic acid mutarotase.
2006, 281, 1426-1431 Substrates of glycosynthase include Glucose, Galactose, Mannose, Xylose, and Glucuronic acid.Wilkinson, S.; Liew, C.; Mackay, J.; Salleh, H.; Withers, S.; McLeod, M. Org Lett. 2008, 10, 1585-1588. Modern methods to prepare glycosynthase use directed evolution to introduce modifications, which improve the enzymes function.
Globotriaosylceramide (R is a carbon chain) Globotriaosylceramide is a globoside. It is also known as CD77, Gb3, GL3, and ceramide trihexoside. It is one of the few clusters of differentiation that is not a protein. It is formed by the alpha linkage of galactose to lactosylceramide catalyzed by A4GALT.
Trifolin is a chemical compound. It is the kaempferol 3-galactoside. It can be found in Camptotheca acuminata, in Euphorbia condylocarpa or in Consolida oliveriana. Kaempferol 3-O-galactosyltransferase is an enzyme that catalyzes the chemical reaction: UDP-galactose + kaempferol → UDP + kaempferol 3-O-beta-D-galactoside (trifolin).
Some monosaccharides have a sweet taste. But all the compounds which fit into this general formula may not be classified as carbohydrates. For example, Acetic Acid which fits in the formula is not a carbohydrate.NCERT TEXT BOOK CLaSS-12 Examples of monosaccharides include glucose (dextrose), fructose (levulose), and galactose.
Galactosyltransferase I is one of seven β-1,4-galactosyltransferase (β4GalT) enzymes. These enzymes are type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a β-1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. As type II membrane proteins, they have an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. By sequence similarity, the beta4GalTs form four groups: β4GalT1 and β4GalT2, β4GalT3 and β4GalT4, β4GalT5 and β4GalT6, and β4GalT7.
Glucose transporters are integral membrane proteins that mediate the transport of glucose and structurally related substances across cellular membranes. Two families of glucose transporter have been identified: the facilitated diffusion glucose transporter family (GLUT family), also known as uniporters, and the sodium-dependent glucose transporter family (SGLT family), also known as cotransporters or symporters. The SLC5A1 gene encodes the sodium glucose cotransporter protein that is involved in the facilitated transport of glucose and galactose into eukaryotic and prokaryotic cells. The role of the sodium-glucose cotransporter 1 is to absorb D-glucose and D-galactose from the brush-border membrane of the small intestines, while also exchanging sodium ions and glucose from the tubule of the nephron.
An experiment published in the International Journal of Dairy Technology suggested that the level of galactose, a monosaccharide sugar that is less sweet than glucose and fructose, can be reduced using different culture techniques. An article in the International Journal of Food Engineering found that trisodium citrate, a food additive used to preserve and add flavor to foods, slightly improved the preferred qualities of pizza cheese. Research published in Dairy Industries International suggested that denatured whey proteins increased moisture retention, but that the improvements were very slight and not economically worthwhile relative to the minor improvements. Some consumers prefer pizza cheese with less browning, which can be achieved using low-moisture part-skim Mozzarella with a low galactose content.
In preclinical research, HT-29 cells have been studied for their ability to differentiate and thus simulate real colon tissue in vitro, a characteristic that has made HT-29 useful for epithelial cell research. The cells can also be tested in vivo via xenografts with rodents. HT-29 cells terminally differentiate into enterocytes with the replacement of glucose by galactose in cell culture, and with the addition of butyrate or acids, the differentiation pathways can be closely studied along with their dependence on surrounding conditions. Accordingly, studies of HT-29 cells have shown induced differentation as a result of forskolin, Colchicine, nocodazole, and taxol, with galactose-mediated differentiation also causing the strengthening of adherens junctions.
In enzymology, a lactosylceramide beta-1,3-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + D-galactosyl-1,4-beta-D-glucosyl-R \rightleftharpoons UDP + D-galactosyl-1,3-beta-D-galactosyl-1,4-beta-D-glucosyl-R Thus, the two substrates of this enzyme are UDP-galactose and D-galactosyl-1,4-beta-D- glucosyl-R, whereas its two products are UDP and D-galactosyl-1,3-beta-D- galactosyl-1,4-beta-D-glucosyl-R. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:D-galactosyl-1,4-beta-D-glucosyl-R beta-1,3-galactosyltransferase. Other names in common use include uridine diphosphogalactose-lactosylceramide, and beta1->3-galactosyltransferase.
In enzymology, an inositol 3-alpha-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + myo-inositol \rightleftharpoons UDP + O-alpha-D-galactosyl-(1->3)-1D-myo-inositol Thus, the two substrates of this enzyme are UDP-galactose and myo-inositol, whereas its two products are UDP and O-alpha-D-galactosyl-(1->3)-1D-myo-inositol. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP- galactose:myo-inositol 3-alpha-D-galactosyltransferase. Other names in common use include UDP-D-galactose:inositol galactosyltransferase, UDP-galactose:myo- inositol 1-alpha-D-galactosyltransferase, UDPgalactose:myo-inositol 1-alpha-D- galactosyltransferase, galactinol synthase, inositol 1-alpha- galactosyltransferase, and uridine diphosphogalactose-inositol galactosyltransferase.
Galactose oxidase contains 639 amino acids. It is a single peptide monomer that has three β-structural domains. Domain 1 (residues 1-155) is a β-sandwich consisting of eight antiparallel β-strands. It contains a possible binding site for Na+ or Ca2+, which may serve structural roles in the protein.
Glycoside hydrolase family 35 CAZY GH_35 comprises enzymes with only one known activity; beta-galactosidase (). Mammalian beta- galactosidase is a lysosomal enzyme (gene GLB1) which cleaves the terminal galactose from gangliosides, glycoproteins, and glycosaminoglycans and whose deficiency is the cause of the genetic disease Gm(1) gangliosidosis (Morquio disease type B).
While study of the regulation of integration and excision of phage lambda in E coli has been a primary focus of his research, Dr. Campbell and research associates also studied regulation and expression of E coli genes linked to the lambda insertion location, including the biotin (bio) and galactose (gal) genes.
Galectins essentially bind to glycans featuring galactose and its derivatives. However, physiologically, they are likely to require lactose or N-aceyllactosamine for significantly strong binding. Generally, the longer the sugar the stronger the interactions. For example, galectin-9 binds to polylactosamine chains with stronger affinity than to an N-acetyllactosamine monomer.
The brain uses mostly glucose for energy; if glucose is insufficient however, it switches to using fats. Monosaccharides contain one sugar unit, disaccharides two, and polysaccharides three or more. Monosaccharides include glucose, fructose and galactose. Disaccharides include sucrose, lactose, and maltose; purified sucrose, for instance, is used as table sugar.
Lactulose was first made in 1929, and has been used medically since the 1950s. It is on the World Health Organization's List of Essential Medicines. It is available as a generic and brand-name product. Lactulose is made from the milk sugar lactose, which is composed of two simple sugars, galactose and glucose.
S. xylosus is normally sensitive to fleroxacin, methicillin, penicillin, teicoplanin, erythromycin and tetracycline, and resistant to novobiocin. It is highly active biochemically, producing acid from a wide variety of carbohydrates. Acid and gas are produced from D-(+)-galactose, D-(+)-mannose, D-(+)-mannitol, maltose, and lactose. Caseinolytic and gelatinase activities are normally present.
The co-transport of glucose into epithelial cells via the SGLT1 protein requires sodium. Two sodium ions and one molecule of glucose (or galactose) are transported together across the cell membrane via the SGLT1 protein. Without glucose, intestinal sodium is not absorbed. This is why oral rehydration salts include both sodium and glucose.
Historically, there has been no broadly accepted standard of care for infants with DG.Fernhoff, P.M., Duarte galactosemia: how sweet is it? Clin Chem, 2010. 56(7): p. 1045-6. At present, some healthcare providers recommend partial to complete restriction of milk and other high galactose foods for infants with DG; others do not.
The first glycosynthase was a retaining exoglycosidase that catalyzed the formation of β 1-4 linked glycosides of glucose and galactose. Glycosynthase enzymes have since been expanded to include mutants of endoglycosidase,Malet, C.; Planas, A. FEBS Letters. 1998, 440, 208-212 as well as mutants of inverting glycosidase.Honda, Y.; Kitaoka, M. JBC.
Lactose synthase is an enzyme that generates lactose from glucose and UDP- galactose. It is classified under . It consists of N-acetyllactosamine synthase and alpha-lactalbumin. Alpha-lactalbumin, which is expressed in response to prolactin, increases the affinity of N-acetyllactosamine synthase for its substrate, causing increased production of lactose during lactation.
This is also observed in Rhinella icterica. The mucous cells in this toad species also produces neutral glycoproteins that are rich in galactose, galactosamine, and glucosamine residues. This is similar to other toad species whose mucous layer that serves to protect the surface of the stomach and is formed by neutral glycoconjugates.
FSH has a beta subunit of 111 amino acids (FSH β), which confers its specific biologic action, and is responsible for interaction with the follicle-stimulating hormone receptor. The sugar portion of the hormone is covalently bonded to asparagine, and is composed of N-acetylgalactosamine, mannose, N-acetylglucosamine, galactose, and sialic acid.
This species of yeast is within the Saccharomyces clade and can be isolated from a variety of substrates and is unique in that it cannot live on galactose and is cryotolerant. Shown in Figure 2 is a summary of activity when grown on a variety of substrates. S. kudriavzevii, compared to S. cerevisiae.
Dr. Luis Leloir deduced the role of GALE in galactose metabolism during his tenure at the Instituto de Investigaciones Bioquímicas del Fundación Campomar, initially terming the enzyme waldenase. Dr. Leloir was awarded the 1970 Nobel Prize in Chemistry for his discovery of sugar nucleotides and their role in the biosynthesis of carbohydrates.
Streptomyces brasiliensis is a bacterium species from the genus of Streptomyces which has been isolated from soil.UniProt Streptomyces brasiliensis produces neomycin. Streptomyces brasiliensis has vast sporulation when it is cultured by galactose and glutamic acid as carbon and nitrogen sources. The colony is red pink or red orange, pigment is not permeable.
Vitamin C biosynthesis in plants There are many different biosynthesis pathways for ascorbic acid in plants. Most of these pathways are derived from products found in glycolysis and other pathways. For example, one pathway goes through the plant cell wall polymers. The plant ascorbic acid biosynthesis pathway most principal seems to be -galactose.
Aldose reductase is able to dip into this galactose reservoir and synthesize significant amounts of galactitol. As is mentioned above, galactitol is not a suitable substrate for the enzyme, polyol dehydrogenase, which catalyzes the next step in the carbohydrate metabolic cycle. Thus, the sugar alcohol idly begins to accumulate in the lens.
The precise composition of porphyran shows seasonal and environmental variations. In Porphyra haitanensis, the L-residues are mainly composed of alpha-L-galactosyl 6-sulfate units, and the 3,6-anhydro-galactosyl units are minor. In Porphyra capensis, the ratio of alpha-L-galactose-6-sulfate and the 3,6-anhydrogalactose is 1.2:1.
In enzymology, a N-acetyllactosaminide 3-alpha-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + beta-D- galactosyl-(1->4)-beta-N-acetyl-D-glucosaminyl-R \rightleftharpoons UDP + alpha-D-galactosyl-(1->3)-beta-D-galactosyl-(1->4)-beta-N- acetylglucosaminyl-R Thus, the two substrates of this enzyme are UDP-galactose and beta-D-galactosyl-(1->4)-beta-N-acetyl-D-glucosaminyl-R, whereas its 3 products are UDP, alpha-D-galactosyl-(1->3)-beta-D-galactosyl-(1->4)-beta-N-, and acetylglucosaminyl-R. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:N-acetyllactosaminide 3-alpha-D- galactosyltransferase. Other names in common use include alpha- galactosyltransferase, UDP-Gal:beta-D-Gal(1,4)-D-GlcNAc alpha(1,3)-galactosyltransferase, UDP-Gal:N-acetyllactosaminide alpha(1,3)-galactosyltransferase, UDP-Gal:N-acetyllactosaminide alpha-1,3-D-galactosyltransferase, UDP-Gal:Galbeta1->4GlcNAc-R alpha1->3-galactosyltransferase, UDP-galactose-acetyllactosamine alpha-D- galactosyltransferase, UDPgalactose:beta-D-galactosyl-beta-1,4-N-acetyl-D- glucosaminyl-, glycopeptide alpha-1,3-D-galactosyltransferase, glucosaminylglycopeptide alpha-1,3-galactosyltransferase, uridine diphosphogalactose-acetyllactosamine, alpha1->3-galactosyltransferase, uridine diphosphogalactose-acetyllactosamine galactosyltransferase, uridine, diphosphogalactose-, galactosylacetylglucosaminylgalactosylglucosylceramide, galactosyltransferase, beta-D-galactosyl-N-acetylglucosaminylglycopeptide, and alpha-1,3-galactosyltransferase.
Supporting evidence comes from that mutation of this tryptophan residue leads to a lower stability of the active form of galactose oxidase. Additionally, the outer sphere of the active site consists of many aromatic residues that give the active site a hydrophobic character. There are also extensive hydrogen bonding networks surround the active site.
These modifications produce 8 core structures known to date. Different cells have different enzymes that can add further sugars, known as glycosyltransferases, and structures therefore change from cell to cell. Common sugars added include galactose, N-acetylglucosamine, fucose and sialic acid. These sugars can also be modified by the addition of sulfates or acetyl groups.
In extremely rare cases a GALT gene mutation may arise de novo, so that only one parent is a carrier; however, only one case of this has been reported in the literature for galactosemia.Tran, T.T., et al., A De Novo Variant in Galactose-1-P Uridylyltransferase (GALT) Leading to Classic Galactosemia. JIMD Rep, 2015.
Talose is an aldohexose sugar. It is an unnatural monosaccharide that is soluble in water and slightly soluble in methanol. Some etymologists suggest that talose's name derives from the automaton of Greek mythology named Talos, but the relevance is unclear. Talose is a C-2 epimer of galactose and a C-4 epimer of mannose.
To invade, Listeria induces macrophage phagocytic uptake by displaying D-galactose in their teichoic acids that are then bound by the macrophage's polysaccharides. Other important adhesins are the internalins. Listeria uses internalin A and B to bind to cellular receptors. Internalin A binds to E-cadherin, while internalin B binds to the cell's Met receptors.
Periodic acid-Schiff(PAS) stain. Prototheca has been thought to be a mutant of Chlorella, a type of single-celled green alga. However, while Chlorella contains galactose and galactosamine in the cell wall, Prototheca lacks these. Also, Chlorella obtains its energy through photosynthesis, while Prototheca is saprotrophic, feeding on dead and decaying organic matter.
Like the chondroitin sulfate proteoglycans, keratan sulfate proteoglycan (KSPG) production is up regulated in reactive astrocytes as part of glial scar formation. KSPGs have also been shown to inhibit neurite outgrowth extension, limiting nerve regeneration. Keratan sulfate, also called keratosulfate, is formed from repeating disaccharide galactose units and N-acetylglucosamines. It is also 6-sulfated.
Galactosaminogalactan (commonly abbreviated as GAG or GG), is an exopolysaccharide composed of galactose and N-acetylgalactosamine (GalNAc). It is commonly found in the biofilm and cell wall of various fungal species.Bardalaye, P.C., and Nordin, J.H. (1976). Galactosaminogalactan from cell walls of Aspergillus niger. J Bacteriol 125, 655-669Takada, H., Arakj, Y., Ito, E. (1980).
The hydrolysis of X-gal by B-galactosidase produces galactose, a blue colored compound. Therefore, when the bacteria is transformed with the recombinant plasmid B-galactosidase is inactive and the colonies appear white, but when bacteria are transformed with the original plasmid, lacking the target gene, B-galactosidase is active and the colonies appear blue.
Their severity typically depends on the amount a person eats or drinks. Lactose intolerance does not cause damage to the gastrointestinal tract. Lactose intolerance is due to the lack of the enzyme lactase in the small intestines to break lactose down into glucose and galactose. There are four types: primary, secondary, developmental, and congenital.
Commercially produced powder of pectin, extracted from citrus fruits. Pectin (from ', "congealed, curdled".) is a structural acidic heteropolysaccharide contained in the primary and middle lamella and cell walls of terrestrial plants. Its main component is galacturonic acid, a sugar acid derived from galactose. It was first isolated and described in 1825 by Henri Braconnot.
X-gal (also abbreviated BCIG for 5-bromo-4-chloro-3-indolyl-β-D- galactopyranoside) is an organic compound consisting of galactose linked to a substituted indole. The compound was synthesized by Jerome Horwitz and collaborators in Detroit, MI, in 1964.Horwitz JP and 7 others, 1964. Substrates for cytochemical demonstration of enzyme activity.
J Immunol. 2012 Sep 15;189(6):3007-17. except trace amount in thymus and immune cells, suggesting a selection pressure during evolution. Obviously, the immune selection pressure against iGb3 is mechanistically different from the well known anti-alpha-Gal antibodies, which caused the loss of alpha1,3-galactose epitope on glycoproteins in humans, apes, and old world monkeys.
Once this initial sugar has been added, other glycosyltransferases can catalyse the addition of additional sugars. Two of the most common structures formed are Core 1 and Core 2. Core 1 is formed by the addition of a galactose sugar onto the initial GalNAc. Core 2 consists of a Core 1 structure with an additional N-acetylglucosamine (GlcNAc) sugar.
Alpha-galactosidase (α-GAL, also known as α-GAL A; E.C. 3.2.1.22) is a glycoside hydrolase enzyme that hydrolyses the terminal alpha-galactosyl moieties from glycolipids and glycoproteins. Glycosidase is an important class of enzyme catalyzing many catabolic processes, including cleaving glycoproteins and glycolipids, and polysaccharides. Specifically, α-GAL catalyzes the removal of the terminal α-galactose from oligosaccharides.
A double displacement reaction mechanism of α-GAL's catalytic action.The ligand (black) when bound in the active site of the enzyme (blue). The two key amino acid residues in the active site are Asp-170 and Asp-231. First, Asp-170 performs a nucleophilic attack on the glycosidic bond to release the terminal α-galactose molecule from the ligand.
Hemicelluloses are polysaccharides related to cellulose that comprise about 20% of the biomass of land plants. In contrast to cellulose, hemicelluloses are derived from several sugars in addition to glucose, especially xylose but also including mannose, galactose, rhamnose, and arabinose. Hemicelluloses consist of shorter chains – between 500 and 3000 sugar units. Furthermore, hemicelluloses are branched, whereas cellulose is unbranched.
4500 mg/100g. In arabica green coffee beans, the content of free glucose was 30 to 38 mg/100g, free fructose 23 to 30 mg/100g; free galactose 35 mg/100g and mannitol 50 mg/100g dried coffee beans, respectively. Mannitol is a powerful scavenger for hydroxyl radicals, which are generated during the peroxidation of lipids in biological membranes.
Despite the lack of cell wall of the ectoplasmic net, each individual cell is surrounded by a cell wall located close to the cell membrane and composed of a single layer of Golgi- derived circular scales, which overlap over a few nanometers, but do not fuse. The main components of the cell wall are fructose or galactose-derived substances.
Comparisons with the leucine transporter LeuT(Aa) and the galactose transporter vSGLT reveal that the outward- and inward-facing cavities are symmetrically arranged on opposite sides of the membrane. The reciprocal opening and closing of these cavities is synchronized by the inverted repeat helices 3 and 8, providing the structural basis of the alternating access model for membrane transport.
This induces the activity of the operon, which will increase the rate of galactose metabolism. The gal operon is also controlled by CRP-cAMP, similarly to the lac operon. CRP-cAMP binds to the -35 region, promoting transcription from PG1 but inhibiting transcription from PG2. This is accomplished due to the location of the activation sequence.
Inborn errors of carbohydrate metabolism are inborn error of metabolism that affect the catabolism and anabolism of carbohydrates. An example is lactose intolerance. Carbohydrates account for a major portion of the human diet. These carbohydrates are composed of three principal monosaccharides: glucose, fructose and galactose; in addition glycogen is the storage form of carbohydrates in humans.
Glycation pathway via Amadori Rearrangement (in HbA1c, R is typically N-terminal valine). Imidazolones (R = CH2CH(OH)CH(OH)CH2OH) are typical glycation products. They arise by the condensation of 3-deoxyglucosone with the guanidine group of an arginine residue. Glycations occur mainly in the bloodstream to a small proportion of the absorbed simple sugars: glucose, fructose, and galactose.
Glucomannan is mainly a straight-chain polymer, with a small amount of branching. The component sugars are β-(1→4)-linked D-mannose and D-glucose in a ratio of 1.6:1. The degree of branching is about 8% through β-(1→6)-glucosyl linkages. Glucomannan with α-(1→6)-linked galactose units in side branches is called galactoglucomannan.
Capsular-polysaccharide endo-1,3-alpha-galactosidase (, polysaccharide depolymerase, capsular polysaccharide galactohydrolase) is an enzyme with systematic name Aerobacter-capsular-polysaccharide galactohydrolase. This enzyme catalyses the following chemical reaction : Random hydrolysis of (1->3)-alpha-D-galactosidic linkages in Aerobacter aerogenes capsular polysaccharide Hydrolyses the galactosyl-alpha-1,3-D-galactose linkages only in the complex substrate, bringing about depolymerization.
Unlike humans, felines are able to utilize simple sugars glucose and galactose in a specialized pathway which occurs in the liver, referred to as the glucuronate pathway. This pathway ultimately produces the active form of vitamin C and maintains it at an adequate level; therefore it does not need to be separately included in their diet.
The major compounds are sterols, sugars, flavonoids and saponins. Novel crystalline compounds such as clerodolone, clerodone, clerodol, and a sterol designated clerosterol have been isolated from the root. Seven sugars namely raffinose, lactose, maltose, sucrose, galactose, glucose and fructose were identified. Fumaric acid, caffeic acid esters, β-sitosterol and β-sitosterol glucoside were isolated from the flowers.
Gums contain galactose in form of galacturonic acid. This sugar is part of lactose, which is milk sugar, so consumption of gums in early mammals or their precursors might be a cause for development of mammary glands in mammals along with maternal instincts to feed their offspring and increased body lipids in females of early mammals.
Molecules of carbohydrates and fats consist of carbon, hydrogen, and oxygen atoms. Carbohydrates range from simple monosaccharides (glucose, fructose, galactose) to complex polysaccharides (starch). Fats are triglycerides, made of assorted fatty acid monomers bound to a glycerol backbone. Some fatty acids, but not all, are essential in the diet: they cannot be synthesized in the body.
The second-generation of Glycoazodyes was first reported in 2008. These Glycoazodyes use an etherel linker. An ether group bonds the sugar and the dye to an n-alkane spacer, and the spacer bonds to the dye through another ether group. Like first-generation Glycoazodyes, second-generation Glycoazodyes use glucose, galactose or lactose as the sugar group.
ApoCIII is a relatively small protein containing 79 amino acids that can be glycosylated at threonine-74. The most abundant glycoforms are characterized by an O-linked disaccharide galactose linked to N-acetylgalactosamine (Gal- GalNAc), further modified with up to 2 sialic acid residues. Less abundant glycoforms are characterized by more complex and fucosylated glycan moieties.
Sugars are normally fermented by all Blastobotrys species. Interestingly, B. elegans is the only Blastobotrys species discovered, without the ability to ferment sugar in anaerobic conditions. Subsequently, with the absence of respiration, there is no observed B. elegans growth on D-galactose, D-glucose, D-xylose, lactose, maltose, raffinose, starch and trehalose. It is also unable to ferment insulin.
The progression of galactosemic cataract is generally divided into three stages; initial vacuolar, late vacuolar, and nuclear cataract. The formation of a mature, nuclear, cloudy galactosemic cataract typically surfaces 14 to 15 days after the onset of the galactose diet. Fig. 6 depicts the three stages of galactosemic cataract with their respective changes in lens hydration.
Further, these providers may be opposed to interrupting or reducing breastfeeding when there is no clear evidence it is contraindicated. These providers may argue that the recognized health benefits of breastfeeding outweigh the potential risks of as yet unknown negative effects of continued milk exposure for these infants. For infants with DG who continue to drink milk, some doctors recommend that blood galactose-1-phosphate (Gal-1P) or urinary galactitol be rechecked by age 12 months to ensure that these metabolite levels are normalizing. The rationale FOR restricting milk exposure of infants with DG: Healthcare providers who recommend partial or complete dietary restriction of milk for infants with DG generally cite concern about the unknown long-term consequences of abnormally elevated galactose metabolites in a young child's blood and tissues.
In enzymology, a sn-glycerol-3-phosphate 1-galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + sn-glycerol 3-phosphate \rightleftharpoons UDP + alpha-D-galactosyl-(1,1')-sn-glycerol 3-phosphate Thus, the two substrates of this enzyme are UDP-galactose and sn- glycerol 3-phosphate, whereas its two products are UDP and alpha-D- galactosyl-(1,1')-sn-glycerol 3-phosphate. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:sn-glycerol-3-phosphate 1-alpha-D- galactosyltransferase. Other names in common use include isofloridoside- phosphate synthase, UDP-Gal:sn-glycero-3-phosphoric acid 1-alpha-galactosyl- transferase, UDPgalactose:sn-glycerol-3-phosphate alpha-D- galactosyltransferase, uridine diphosphogalactose-glycerol phosphate galactosyltransferase, and glycerol 3-phosphate 1alpha-galactosyltransferase.
This mutation is highly likely to disrupt the normal function of the encoded protein. GAL3ST4 is typically responsible for catalyzing “the C-3 sulfation of galactoses in O-linked glycoproteins” Seko A, Hara-Kuge S, Yamashita K. Molecular cloning and characterization of a novel human galactose 3-O-sulfotransferase that transfers sulfate to Galβ1→3GalNAc residue in O-glycans. J Biol Chem.
Recent data suggests that aldose reductase is the enzyme responsible for the primary stage of this pathway. Therefore, aldose reductase reduces galactose to its sugar alcohol form, galactitol. Galactitol, however, is not a suitable substrate for the next enzyme in the polyol pathway, polyol dehydrogenase. Thus, galactitol accumulates in body tissues and is excreted in the urine of galactosemic patients.
Most monosaccharides, such as fructose and galactose, can be converted to one of these intermediates. The intermediates may also be directly useful rather than just utilized as steps in the overall reaction. For example, the intermediate dihydroxyacetone phosphate (DHAP) is a source of the glycerol that combines with fatty acids to form fat. Glycolysis is an oxygen-independent metabolic pathway.
Springer-Verlag, 2014, , p. 27\. (german) such as fructose (via the polyol pathway),Peter C. Heinrich: Löffler/Petrides Biochemie und Pathobiochemie. Springer-Verlag, 2014, , p. 199, 200. (german) mannose (the epimer of glucose at position 2), galactose (the epimer at position 4), fucose, various uronic acids and the amino sugars are produced from glucose.Peter C. Heinrich: Löffler/Petrides Biochemie und Pathobiochemie.
Often these compounds are temperature sensitive. Very little research has been done on classifying and identifying carbohydrates within insect adhesive secretions. So far, glucose, trehalose and mucopolysaccharides that contain glucose, galactose, mannose, beta-glucopyranose, and/or (N-acetyl-beta-) glucosamine have been identified as components of insect adhesives. Carbohydrates have been found in defense secretions as well as for sticking eggs together.
It is impossible to distinguish macapuno seeds from normal seeds from the external appearance of the fruits. The only way to ascertain if a seed has the macapuno phenotype is to open it. Normal coconut flesh mostly consists of galactomannan as a source of energy. In the development process, this substrate is degraded into two sub-components, galactose and mannose.
The gal operon is a prokaryotic operon, which encodes enzymes necessary for galactose metabolism. Repression of gene expression for this operon works via binding of repressor molecules to two operators. These repressors dimerize, creating a loop in the DNA. The loop as well as hindrance from the external operator prevent RNA polymerase from binding to the promoter, and thus prevent transcription.
Allolactose is a disaccharide similar to lactose. It consists of the monosaccharides D-galactose and D-glucose linked through a β1-6 glycosidic linkage instead of the β1-4 linkage of lactose. It may arise from the occasional transglycosylation of lactose by β-galactosidase. It is an inducer of the lac operon in Escherichia coli and many other enteric bacteria.
Image:Free text.png In human N-linked glycans, fucose is most commonly linked α-1,6 to the reducing terminal β-N-acetylglucosamine. However, fucose at the non-reducing termini linked α-1,2 to galactose forms the H antigen, the substructure of the A and B blood group antigens. Fucose is released from fucose-containing polymers by an enzyme called α-fucosidase found in lysosomes.
The carbohydrate content can be defined as the sum of the amounts of the five principal, neutral wood monosaccharides; arabinose, galactose, glucose, mannose and xylose in anhydrous form, in a sample, in milligrams per gram. In the determination, the samples are hydrolyzed with sulphuric acid using a two- step technique. The amounts of the different monosaccharides are determined using ion chromatography (IC).
All strains of S. cerevisiae can grow aerobically on glucose, maltose, and trehalose and fail to grow on lactose and cellobiose. However, growth on other sugars is variable. Galactose and fructose are shown to be two of the best fermenting sugars. The ability of yeasts to use different sugars can differ depending on whether they are grown aerobically or anaerobically.
N-Acetylgalactosamine Sphingosine A globoside is a type of glycosphingolipid with more than one sugar as the side chain (or R group) of ceramide. The sugars are usually a combination of N-acetylgalactosamine, D-glucose or D-galactose. A glycosphingolipid that has only one sugar as the side chain is called a cerebroside. The side chain can be cleaved by galactosidases and glucosidases.
Galactosidase, beta 1, also known as GLB1, is a protein which in humans is encoded by the GLB1 gene. The GLB1 protein is a beta-galactosidase that cleaves the terminal beta-galactose from ganglioside substrates and other glycoconjugates. The GLB1 gene also encodes an elastin binding protein. In corn (Zea mays), Glb1 is a gene coding for the storage protein globulin.
N-Linked glycans are attached in the endoplasmic reticulum to the nitrogen (N) in the side chain of asparagine in the sequon. The sequon is an Asn-X-Ser or Asn-X-Thr sequence, where X is any amino acid except proline and the glycan may be composed of N-acetylgalactosamine, galactose, neuraminic acid, N-acetylglucosamine, fucose, mannose, and other monosaccharides.
Spot42 can interact directly with mRNA targets through base pairing. The first Spot 42 target was discovered by Møller et al. who showed that Spot 42 specifically binds to a short complementary region at the translation initiation region of galK (encodes a galactoinase). galK is the third gene in the galactose operon, which contains four genes (galETKM) and produces a polycistronic mRNA.
In enzymology, a galactinol-raffinose galactosyltransferase () is an enzyme that catalyzes the chemical reaction :alpha-D-galactosyl-(1→3)-1D-myo-inositol + raffinose \rightleftharpoons myo-inositol + stachyose Thus, the two substrates of this enzyme are α-D-galactosyl-(1→3)-1D-myo-inositol and raffinose, whereas its two products are myo-inositol and stachyose. This enzyme participates in galactose metabolism.
Phytohaemagglutinin (PHA, or phytohemagglutinin) is a lectin found in plants, especially certain legumes. PHA actually consists of two closely related proteins, called leucoagglutinin (PHA-L) and PHA-E. The letters E and L indicate these proteins agglutinate erythrocytes (red blood cells) and leukocytes (white blood cells) respectively. Phytohaemagglutinin has carbohydrate-binding specificity for a complex oligosaccharide containing galactose, N-acetylglucosamine, and mannose.
Ursolic acid ameliorates cognition deficits and attenuates oxidative damage in the brain of senescent mice induced by D-galactose. Ursolic acid enhances mouse liver regeneration after partial hepatectomy. Ursolic acid enhances the cellular immune system and pancreatic beta-cell function in streptozotocin-induced diabetic mice fed a high-fat diet. UA increased skeletal muscle mass, as well as grip strength and exercise capacity.
This species produces Amylose, but it is the only basidioblastomycete which does so but is unable to also assimilate cellobiose, D-galactose, mannitol, myo-inositol and nitrate. C. consortionis is DBB positive. This species required thiamine for proper growth, and its growth is slowed by small amounts of cycloheximide. C. consortionis does not produce urease, and does not produce melanin on DOPA.
The principal soluble carbohydrates of mature soybeans are the disaccharide sucrose (range 2.5–8.2%), the trisaccharide raffinose (0.1–1.0%) composed of one sucrose molecule connected to one molecule of galactose, and the tetrasaccharide stachyose (1.4 to 4.1%) composed of one sucrose connected to two molecules of galactose. While the oligosaccharides raffinose and stachyose protect the viability of the soybean seed from desiccation (see above section on physical characteristics) they are not digestible sugars, so contribute to flatulence and abdominal discomfort in humans and other monogastric animals, comparable to the disaccharide trehalose. Undigested oligosaccharides are broken down in the intestine by native microbes, producing gases such as carbon dioxide, hydrogen, and methane. Since soluble soy carbohydrates are found in the whey and are broken down during fermentation, soy concentrate, soy protein isolates, tofu, soy sauce, and sprouted soybeans are without flatus activity.
This two-electron oxidation is achieved by the double-redox site: the copper(II) metal center and the free radical, each capable of accepting one electron from the substrate. This double-redox center has three accessible oxidation levels. In the catalytic cycle of galactose oxidase, the enzyme shuttles between the fully oxidized form and the fully reduced form. The semi-oxidized form is the inactive form.
Arabinogalactan is a biopolymer consisting of arabinose and galactose monosaccharides. Two classes of arabinogalactans are found in nature: plant arabinogalactan and microbial arabinogalactan. In plants, it is a major component of many gums, including gum arabic and gum ghatti. It is often found attached to proteins, and the resulting arabinogalactan protein (AGP) functions as both an intercellular signaling molecule and a glue to seal plant wounds.
Rathayibacter toxicus is a chemoorganotroph that utilizes oxygen as its terminal electron acceptor. Using tubes of Medium C containing a variety of carbon sources, each 0.5% weight per volume concentration, noting growth and acid production for 4 weeks, it was determined that R. toxicus utilizes galactose, mannose, and xylose as carbon sources forming acidic byproducts. The production of acids from carbohydrates occurs oxidatively and weakly.
The enzyme encoded by this gene attaches the first galactose in the common carbohydrate-protein (GlcA-β-1,3-Gal-β-1,3-Gal-β-1,4-Xyl-beta1-O-Ser) linkage found in proteoglycans. Manganese is required as a cofactor. This enzyme differs from the other six beta4GalTs because it lacks the conserved β4GalT1-β4GalT6 Cys residues and it is located in cis-Golgi instead of trans-Golgi.
Absolute specificity can be thought of as being exclusive, in which an enzyme acts upon one specific substrate. Absolute specific enzymes will only catalyze one reaction with its specific substrate. For example, lactase is an enzyme specific for the degradation of lactose into two sugar monosaccharides, glucose and galactose. Another example is Glucokinase, which is an enzyme involved in the phosphorylation of glucose to glucose-6-phosphate.
Pseudocnus echinatus has been researched as a possible source of bioactive molecules and has been found to contain a galactose-specific lectin with haemolytic activity. This binds to the exterior of red blood cells, damaging the cell membrane and causing lysis. This lectin has the ability to block the development of Plasmodium, the causal agent of malaria, when it is expressed in genetically modified Anopheles mosquitoes.
Microsporum audouinii is effective in utilizing its carbon sources, but growth is strongest in the hexoses (glucose, mannose and fructose) and weakest in maltose, sucrose, lactose and galactose. It is unable to synthesize the vitamins thiamine, niacin and riboflavin and requires an exogenous supply of these materials to support its growth. The fungus is only able to utilize organic nitrogen sources, particularly nitrogen from arginine and urea.
General structures of sphingolipids Cerebrosides is the common name for a group of glycosphingolipids called monoglycosylceramides which are important components in animal muscle and nerve cell membranes. They consist of a ceramide with a single sugar residue at the 1-hydroxyl moiety. The sugar residue can be either glucose or galactose; the two major types are therefore called glucocerebrosides (a.k.a. glucosylceramides) and galactocerebrosides (a.k.a. galactosylceramides).
All three dietary monosaccharides are transported into the liver by the GLUT2 transporter. Fructose and galactose are phosphorylated in the liver by fructokinase (Km= 0.5 mM) and galactokinase (Km = 0.8 mM), respectively. By contrast, glucose tends to pass through the liver (Km of hepatic glucokinase = 10 mM) and can be metabolised anywhere in the body. Uptake of fructose by the liver is not regulated by insulin.
This might lead to interaction with biomembranes, which is thought to be the basis of its toxicity. The difference between prymnesin-1 and prymnesin-2 is the glycosidic residues: L-arabinose, D-galactose and D-ribose, yet prymnesin-2 and prymnesin-1 show comparable activities. Prymnesins also have unique features: The possession of only one methyl, but three chlorine atoms, acetylene bonds, sugars and an amino group.
Galactose exists in both open-chain and cyclic form. The open-chain form has a carbonyl at the end of the chain. Four isomers are cyclic, two of them with a pyranose (six-membered) ring, two with a furanose (five-membered) ring. Galactofuranose occurs in bacteria, fungi and protozoa, and is recognized by a putative chordate immune lectin intelectin through its exocyclic 1,2-diol.
European mistletoe is potentially fatal, in a concentrated form, and people can become seriously ill from eating the berries.Poison Control The toxic lectin viscumin has been isolated from Viscum album. Viscumin is a cytotoxic protein (ribosome inactivating protein, or RIP) that binds to galactose residues of cell surface glycoproteins and may be internalised by endocytosis. Viscumin strongly inhibits protein synthesis by inactivating the 60 S ribosomal subunit.
The structure of mucin is shown and includes a core protein with O-linked glycans. Being large glycoproteins, mucins have high carbohydrate content, contributing to their fibrous structure. These carbohydrates branch off of polypeptide chains in the form of oligosaccharides including N-acetylgalactosamine, N-acetylglucosamine, fucose, galactose, and sialic acid. The serine and threonine hydroxyl groups link to the polypeptide chains via O-glycosidic linkages.
The determination is made based on the chirality of the asymmetric carbon furthest from the aldehyde end, namely the second-last carbon in the chain. Aldoses with alcohol groups on the right of the Fischer projection are -aldoses, and those with alcohols on the left are -aldoses. -aldoses are more common than -aldoses in nature. Examples of aldoses include glyceraldehyde, erythrose, ribose, glucose and galactose.
An N-terminal domain contains a 7-stranded parallel β-pleated sheet flanked by α-helices. Paired Rossmann folds within this domain allow GALE to tightly bind one NAD+ cofactor per subunit. A 6-stranded β-sheet and 5 α-helices comprise GALE's C-terminal domain. C-terminal residues bind UDP, such that the subunit is responsible for correctly positioning UDP-glucose or UDP-galactose for catalysis.
It can also produce H2S (gas), which is a unique characteristic for a Gram-positive bacillus. Acid is produced from glucose, fructose, galactose, and lactose, but not from maltose, xylose, and mannitol. Sucrose is fermented by most strains of E. tonsillarum, but not by E. rhusiopathiae. Hydrogen sulfide H2S is produced by 95% of strains of Erysipelothrix species as demonstrated on triple sugar iron (TSI) agar.
There are two forms of glucose-6-phosphate dehydrogenase. G form is X-linked and H form, encoded by this gene, is autosomally linked. This H form shows activity with other hexose-6-phosphates, especially galactose-6-phosphate, whereas the G form is specific for glucose-6-phosphate. Both forms are present in most tissues, but H form is not found in red cells.
As galactitol concentration increases in the lens, a hypertonic environment is created. Osmosis favors the movement of water into the lens fibers to reduce the high osmolarity. Figures 2 and 3 show how water concentration increases as galactitol concentration increases inside the lens of galactosemic animals sustained on a galactose diet. This osmotic movement ultimately results in the swelling of lens fibers until they rupture.
Carbohydrates in the cell include glucose, fucose, galactose, and mannose. R. glutinis is heat resistant, an uncommon feature in yeasts without spores, tolerating for 10 minutes. R. glutinis is closely related to Rhodotorula mucilaginosa, differing only in their ability to use nitrate as a nitrogen source, which R. glutinis cannot assimilate. Both species are incapable of fermentation and assimilation of Myo-Inositol and D-glucoronate.
This is another large superfamily of CLRs that includes #The classic asialoglycoprotein receptor macrophage galactose-type lectin (MGL) #DC-SIGN (CLEC4L) #Langerin (CLEC4K) #Myeloid DAP12‑associating lectin (MDL)‑1 (CLEC5A) #DC‑associated C‑type lectin 1 (Dectin1) subfamily which includes ##dectin 1/CLEC7A ##DNGR1/CLEC9A ##Myeloid C‑type lectin‑like receptor (MICL) (CLEC12A) ##CLEC2 (also called CLEC1B)- the platelet activation receptor for podoplanin on lymphatic endothelial cells and invading front of some carcinomas. ##CLEC12B #DC immunoreceptor (DCIR) subfamily which includes: ##DCIR/CLEC4A ##Dectin 2/CLEC6A ##Blood DC antigen 2 (BDCA2) ( CLEC4C) ##Mincle i.e. macrophage‑inducible C‑type lectin (CLEC4E) The nomenclature (mannose versus asialoglycoprotein) is a bit misleading as these the asialoglycoprotein receptors are not necessarily galactose (one of the commonest outer residues of asialo-glycoprotein) specific receptors and even many of this family members can also bind to mannose after which the other group is named.
In the 1980s, a purported new species of Streptococcus, named S. shiloi, was identified as one of the causes of an epidemic of meningoencephalitis (an inflammation of the brain and its surrounding membranes) affecting farmed rainbow trout and tilapia in Israel since 1986. Since S. shiloi was alpha- hemolytic, had a G+C% content of 37% and did not ferment sugar galactose, it was not classified as S. iniae, which is beta-hemolytic, has a G+C% content of 32%, and ferments galactose. In 1995, S. shiloi was found in fact to be beta- hemolytic, and after DNA-DNA hybridization techniques with the ATCC type S. iniae and recalculation of the G+C% content, was reclassified by the same group as a junior synonym of S. iniae. Phylogenetic analyses based on 16S ribosomal DNA suggest that S. iniae is closely related to other streptococcal pathogens of humans and animals.
It does not, however, contain more glucose, and is nutritionally identical to regular milk. Finland, where approximately 17% of the Finnish- speaking population has hypolactasia, has had "HYLA" (acronym for hydrolyzed lactose) products available for many years. Lactose of low-lactose level cow's milk products, ranging from ice cream to cheese, is enzymatically hydrolyzed into glucose and galactose. The ultra-pasteurization process, combined with aseptic packaging, ensures a long shelf life.
Treponema socranskii differs from others in the genus due, in part, to its metabolism. T. socranskii is able to ferment compounds that others are not able to do so. The compounds that it can metabolize are arabinose, dextrin, fructose, galactose, glucose, glycogen, maltose, mannose, pectin, raffinose, rhamnose, ribose, starch, sucrose, trehalose, and xylose. The fermentation products are acetic, lactic, and succinic acid, with formic acid as a minor product.
This enzyme participates in pentose and glucuronate interconversions and fructose and mannose metabolism. The most bio-available sugars according to the International Society of Rare Sugars are: glucose, galactose, mannose, fructose, xylose, ribose, and L-arabinose. Twenty hexoses and nine pentoses, including xylulose, were considered to be "rare sugars". Hence D-xylose isomerase is used to produce these rare sugars which have very important applications in biology despite their low abundance.
Infant mammals nurse on their mothers to drink milk, which is rich in lactose. The intestinal villi secrete the enzyme lactase (β-D-galactosidase) to digest it. This enzyme cleaves the lactose molecule into its two subunits, the simple sugars glucose and galactose, which can be absorbed. Since lactose occurs mostly in milk, in most mammals, the production of lactase gradually decreases with maturity due to a lack of continuing consumption.
Structure of ceramide, galactosylceramide and glucosylceramide. Galactose or glucose sugars can be attached to a hydroxyl group of ceramide lipids in a different form of O-glycosylation, as it does not occur on proteins. This forms glycosphingolipids, which are important for the localisation of receptors in membranes. Incorrect breakdown of these lipids leads to a group of diseases known as sphingolipidoses, which are often characterised by neurodegeneration and developmental disabilities.
Glucose, glycerol, mannose, starch, maltose, sucrose, glutamate, alanine, ornithine, fumarate, malate, pyruvate, succinate, and lactate substrates support growth. Growth is not sustained on arabinose, lactose, mannitol, rhamnose, sorbitol, galactose, ribose, xylose, arginine, lysine, aspartate, glycine, acetate, propionate, and citrate. Sensitivity to novobiocin, bacitracin, anisomycin, aphidicolin, and rifampicin have been observed. However, no sensitivity has been shown to ampicillin, penicillin, chloramphenicol, erythromycin, neomycin, nalidixic acid, nystatin, tetracycline, streptomycin, or kanamycin.
Ribulose and xylulose occur in the pentose phosphate pathway. Galactose, a component of milk sugar lactose, is found in galactolipids in plant cell membranes and in glycoproteins in many tissues. Mannose occurs in human metabolism, especially in the glycosylation of certain proteins. Fructose, or fruit sugar, is found in many plants and humans, it is metabolized in the liver, absorbed directly into the intestines during digestion, and found in semen.
Tn antigen refers to the monosaccharide structure N-acetylgalactosamine (GalNAc) linked to serine or threonine by a glycosidic bond.I. Brockhausen, H. Schachter, P. Stanley, Essentials of Glycobiology, 2nd edition. A. Varki, R. Cummings, J. Esko, Eds, Cold Spring Harbor (NY): Cold Spring Harbor Laboratory Press; 2009. Chapter 9, O-GalNAc Glycans Addition of an additional galactose monosaccharide creates a disaccharide antigen: the Thomsen-Friedenreich antigen (Gal(b1-3)GalNAc).
Soyasapogenol B glucuronide galactosyltransferase (, UDP-galactose:SBMG- galactosyltransferase, UGT73P2, GmSGT2 (gene), UDP-galactose:soyasapogenol B 3-O-glucuronide beta-D-galactosyltransferase) is an enzyme with systematic name UDP-alpha-D-galactose:soyasapogenol B 3-O-glucuronide beta-D- galactosyltransferase. This enzyme catalyses the following chemical reaction : UDP-alpha-D-galactose + soyasapogenol B 3-O-beta-D-glucuronide \rightleftharpoons UDP + soyasaponin III This enzyme takes part of the biosynthetic pathway for soyasaponins.
The immune responses of A. pernyi to bacterial infection have been analysed based on injection by Escherichia coli D31. Cecropin B and D, hemolin, attacin and lysozyme were detected in the hemolymph. Also, injection of E. coli led to the discovery of a 380-kDa lectin with affinity to galactose and resulted in an increase of hemagglutinating activity. A. pernyi has been used in research on virus defence in insects.
The protein encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. The encoded protein is normally found in the Golgi apparatus but can be proteolytically processed to a soluble form. This protein is a member of glycosyltransferase family 29. Multiple transcript variants encoding several different isoforms have been found for this gene.
T. naphthophila requires yeast extract, peptone, glucose, galactose, fructose, mannitol, ribose, arabinose, sucrose, lactose, maltose or starch as the sole carbon and energy source for nutrient requirements. Thermotoga naphthophila was unable to survive on proteins, amino acids, organic acids, alcohols, chitin, or hydrocarbons as a sole carbon and energy source. According to the Takahata et.al., lactate, acetate, carbon dioxide, and hydrogen gas are its end products from glucose fermentation.
Jacobsen and coworkers identified the thiourea-catalyzed glycosylation of galactose as a reaction that met both of the aforementioned criteria (expensive materials and unstable substrates) and was a reaction with a poorly understood mechanism. Glycosylation is a special case of nucleophilic substitution that lacks clear definition between SN1 and SN2 mechanistic character. The presence of the oxygen adjacent to the site of displacement (i.e., C1) can stabilize positive charge.
The immunochemistry of Hafnia lipopolysaccharides (LPS) are extremely complicated. All H. alvei LPS appear to contain glucose, glucosamine, heptose, and 3-deoxyoctulosonic acid. Some LPS also contain other amino sugars or carbohydrates such as mannose, galactose, galactosamine, and mannosamine. The core oligosaccharide structure of some strains consists of an identical hexasaccharide structure composed of two D-glucose residues, three LD-heptose residues, and one 3-deoxyoctulosonic acid residue.
All mammals, except humans and higher apes, have a carbohydrate, commonly known as alpha- gal (alpha-1, 3-galactose) in their tissue fluids. When a tick feeds on the blood of a mammal (bandicoot, possum, cat, dog etc.) it takes alpha-gal into the tick's digestive system. When the same tick attaches to the next host (e.g. a human) it transfers the alpha-gal to the tissues of that next host.
Core 2 glycans terminate in galactose or sialic acid, whereas core 1 is branched and has potential for large carbohydrate extensions. High levels of MUC-1 are associated with poor prognosis and increased potential of metastasis. This cancer-associated MUC-1 is a natural ligand for galectin-3. In normal cells, MUC-1 has distinct polarisation and acts as a protective barrier around the cell, reducing cell-cell interactions.
Stachyose is a tetrasaccharide consisting of two α--galactose units, one α-- glucose unit, and one β--fructose unit sequentially linked as gal(α1→6)gal(α1→6)glc(α1↔2β)fru. Together with related oligosaccharides such as raffinose, Stachyose occurs naturally in numerous vegetables (e.g. green beans, soybeans and other beans) and other plants. Stachyose is less sweet than sucrose, at about 28% on a weight basis.
EC 2.4 includes enzymes that transfer glycosyl groups, as well as those that transfer hexose and pentose. Glycosyltransferase is a subcategory of EC 2.4 transferases that is involved in biosynthesis of disaccharides and polysaccharides through transfer of monosaccharides to other molecules. An example of a prominent glycosyltransferase is lactose synthase which is a dimer possessing two protein subunits. Its primary action is to produce lactose from glucose and UDP-galactose.
Galactosemia renders infants unable to process the sugars in breast milk, which leads to vomiting and anorexia within days of birth. Most symptoms of the disease are caused by a buildup of galactose-1-phosphate in the body. Common symptoms include liver failure, sepsis, failure to grow, and mental impairment, among others. Buildup of a second toxic substance, galactitol, occurs in the lenses of the eyes, causing cataracts.
Glucose and galactose can be absorbed by the small intestine. Approximately 65 percent of the adult population produce only small amounts of lactase and are unable to eat unfermented milk-based foods. This is commonly known as lactose intolerance. Lactose intolerance varies widely by genetic heritage; more than 90 percent of peoples of east Asian descent are lactose intolerant, in contrast to about 5 percent of people of northern European descent.
In enzymology, a glucoside 3-dehydrogenase () is an enzyme that catalyzes the chemical reaction :sucrose + acceptor \rightleftharpoons 3-dehydro-alpha-D- glucosyl-beta-D-fructofuranoside + reduced acceptor Thus, the two substrates of this enzyme are sucrose and acceptor, whereas its two products are 3-dehydro-alpha-D-glucosyl-beta-D-fructofuranoside and reduced acceptor. This enzyme participates in galactose metabolism and starch and sucrose metabolism. It employs one cofactor, FAD.
Monosaccharides are the building blocks of disaccharides (such as sucrose and lactose) and polysaccharides (such as cellulose and starch). Each carbon atom that supports a hydroxyl group is chiral, except those at the end of the chain. This gives rise to a number of isomeric forms, all with the same chemical formula. For instance, galactose and glucose are both aldohexoses, but have different physical structures and chemical properties.
L. brevis has been shown to actively transport glucose and galactose. When fructose was used as a carbon source there was only some growth and L. brevis was able to partially metabolize the fructose to mannitol. Normal growth follows the lactic acid pathway that is commonly used by most lactic acid bacterium. There are some strains that poorly metabolize glucose, whereas other strain are able to easily metabolize the sugar.
Aspergillus wentii is a filamentous fungus. In culture, optimal growth of Aspergillus wentii occurs on glucose media at pH 6.0 at a temperature of 30 °C. Aspergillus wentii grows well on carbon-based media supplemented with mannitol, fructose, galactose, sucrose, lactose, or maltose. Generally, Aspergillus wentii exhibits the highest growth rates in carbon-based media, although it can be grown on nitrogen-based media with lower growth yields.
The mechanism of this drug is currently unknown. Resistance is conferred by mutations in PfCARL, a protein with 7 transmembrane domains, as well as by mutations in the P. falciparum acetyl-CoA transporter and the UDP-galactose transporter. None of these are thought to be the target of ganaplacide. Initial functional studies were performed with the closely related chemotype, GNF179 that differs from the clinical candidate by a single halogen.
S. hominis is the predominant species on the head, axillae, arms, and legs. S. hominis, as well as most other staphylococcal species common on the human skin, is able to produce acid aerobically from glucose, fructose, sucrose, trehalose, and glycerol. Some strains were also able to produce acid from turanose, lactose, galactose, melezitose, mannitol, and mannose. Most strains colonize on the skin for relatively short periods of time compared to other Staphylococcus species.
It contains a single copper center that adopts square planar or square-based pyramidal coordination geometry. The copper center has five coordinating ligands: two tyrosines (Tyr272 and Tyr495), two histidines (His496 and His581), and a solvent molecule that is usually water. The copper in the active site of galactose oxidase is described as having a "distorted square pyramidal" coordination geometry. Tyr495 is the axial ligand, the other four ligands lie roughly in a plane.
The optimum temperature for human lactase is about 37 °C and the optimum pH is 6. In metabolism, the β-glycosidic bond in D-lactose is hydrolyzed to form D-galactose and D-glucose, which can be absorbed through the intestinal walls and into the bloodstream. The overall reaction that lactase catalyzes is C12H22O11 \+ H2O → C6H12O6 \+ C6H12O6 \+ heat. The catalytic mechanism of D-lactose hydrolysis retains the substrate anomeric configuration in the products.
It grows between and , with an optimum temperature of , and between pH 5 and 9 (with an optimum at pH 7). It grows well on yeast extract, maltose, cellobiose, β-glucans, starch, and protein sources (tryptone, peptone, casein, and meat extracts). This is a relatively wide range when compared to other archaea. Growth is very slow, or nonexistent, on amino acids, organic acids, alcohols, and most carbohydrates (including glucose, fructose, lactose, and galactose).
Lactosylceramide 4-alpha-galactosyltransferase is an enzyme that in humans is encoded by the A4GALT gene. The protein encoded by this gene catalyzes the transfer of galactose to lactosylceramide to form globotriaosylceramide, which has been identified as the P(k) antigen of the P blood group system. The encoded protein, which is a type II membrane protein found in the Golgi, is also required for the synthesis of the bacterial verotoxins receptor.
This enzymatic step requires vitamin C as a cofactor. In scurvy, the lack of hydroxylation of prolines and lysines causes a looser triple helix (which is formed by three alpha peptides). ## Glycosylation occurs by adding either glucose or galactose monomers onto the hydroxyl groups that were placed onto lysines, but not on prolines. ## Once these modifications have taken place, three of the hydroxylated and glycosylated propeptides twist into a triple helix forming procollagen.
Gum karaya or gum sterculia, also known as Indian gum tragacanth, is a vegetable gum produced as an exudate by trees of the genus Sterculia. Chemically, gum karaya is an acid polysaccharide composed of the sugars galactose, rhamnose and galacturonic acid. It is used as a thickener and emulsifier in foods, as a laxative, and as a denture adhesive. It is also used to adulterate Gum tragacanth due to their similar physical characteristics.
The mechanism proceeds in the same manner as all other β-galactosidase-catalyzed cleavages. The carboxyl group on a glutamic acid side chain within the enzyme acts as an acid catalyst, hastening the cleavage of the glycosidic bond at the C-1 position in the sugar. This cleavage gives water access to the paramagnetic center. The result of the enzyme-catalyzed reaction is a free galactose molecule and an activated contrast agent.
During this time, his team dedicated itself to the study of glycoproteins; Leloir and his colleagues elucidated the primary mechanisms of galactose metabolism (now coined the Leloir pathwayHolton JB, Walter JH, and Tyfield LA. "Galactosemia" in The Metabolic and Molecular Bases of Inherited Disease, 8th edition, 2001. Scriver, Beaudet, et al., McGraw-Hill, vol I, chapter 72, p.1553-1587.) and determined the cause of galactosemia, a serious genetic disorder that resulted in lactose intolerance.
N-acetyllactosamine synthase is a galactosyltransferase enzyme. It is a component of lactose synthase[citation needed] This enzyme modifies the connection between two molecule UDP-galactose and N-actyl-D-glucosamine and generates two different molecules UDP and N-acetyllactosamine as products. The main function of the enzyme is associated with the biosynthesis of glycoproteins and glycolipids in both human and animals. In human, the activity of this enzyme can be found in Golgi apparatus.
The biosynthesis of monoglycosylceramides requires a direct transfer of the carbohydrate moiety from a sugar-nucleotide, such as uridine 5-diphosphate(UDP)-galactose, or UDP-glucose to the ceramide unit. The glycosyl-transferase catalyzed reaction results in an inversion of the glycosidic bond stereochemistry, changing from α →β. Synthesis of galactosylceramide, and glucosylceramide occurs on the lumenal surface of the endoplasmic reticulum, and on the cytosolic side of the early Golgi membranes respectively.
Galectin-1 has been shown to enhance HIV infection due to its galactose binding specificity. HIV preferentially infects CD4+ T cells and other cells of the immune system, immobilising the adaptive immune system. HIV is a virus that infects CD4+ cells via binding of its viral envelope glycoprotein complex, which consists of gp120 and gp41. The gp120 glycoprotein contains two types of N-glycan, high mannose oligomers and N-acetyllactosamine chains on a trimannose core.
Galactan endo-1,6-beta-galactosidase (, endo-1,6-beta-galactanase) is an enzyme with systematic name endo-beta-(1->6)-galactanase. This enzyme catalyses the following chemical reaction : Endohydrolysis of (1->6)-beta-D- galactosidic linkages in arabinogalactan proteins and (1->3):(1->6)-beta- galactans to yield galactose and (1->6)-beta-galactobiose as the final products The enzyme specifically hydrolyses 1,6-beta-D-galactooligosaccharides with a degree of polymerization (DP) higher than 3.
Galactose is a type of sugar found in dairy products and other foods that is less sweet than glucose. Sugar in foods can lead to caramelization when they are cooked, which increases their browning. Some varieties derived from skim mozzarella variants were designed not to require aging or the use of fermentation starter. Others can be produced through the direct acidification of milk, which may be used in place of bacterial fermentation.
The root is known to be a powerful emetic. A proteolytic enzyme known as pedilanthain can be extracted from the plant's latex, and has been shown in experiments to be effective against intestinal worms and to reduce inflammation when ingested. In 1995, a galactose-specific lectin was purified from the plant's latex, and indications are that it might be useful in combatting diabetes mellitus.Van Damme, Handbook of Plant Lectins: Properties and Biomedical Applications, 1998, p.
Image:Free review.png Two structural features distinguish fucose from other six-carbon sugars present in mammals: the lack of a hydroxyl group on the carbon at the 6-position (C-6) (thereby making it a deoxy sugar) and the L-configuration. It is equivalent to 6-deoxy--galactose. In the fucose- containing glycan structures, fucosylated glycans, fucose can exist as a terminal modification or serve as an attachment point for adding other sugars.
In humans, dietary starches are composed of glucose units arranged in long chains called amylose, a polysaccharide. During digestion, bonds between glucose molecules are broken by salivary and pancreatic amylase, resulting in progressively smaller chains of glucose. This results in simple sugars glucose and maltose (2 glucose molecules) that can be absorbed by the small intestine. Lactase is an enzyme that breaks down the disaccharide lactose to its component parts, glucose and galactose.
Examples of monosaccharides are the hexoses, glucose, fructose, Trioses, Tetroses, Heptoses, galactose, pentoses, ribose, and deoxyribose. Consumed fructose and glucose have different rates of gastric emptying, are differentially absorbed and have different metabolic fates, providing multiple opportunities for 2 different saccharides to differentially affect food intake. Most saccharides eventually provide fuel for cellular respiration. Disaccharides are formed when two monosaccharides, or two single simple sugars, form a bond with removal of water.
The reverse reaction in which the glycosidic bond of a disaccharide is broken into two monosaccharides is termed hydrolysis. The best-known disaccharide is sucrose or ordinary sugar, which consists of a glucose molecule and a fructose molecule joined together. Another important disaccharide is lactose found in milk, consisting of a glucose molecule and a galactose molecule. Lactose may be hydrolysed by lactase, and deficiency in this enzyme results in lactose intolerance.
Glucose can exist in both a straight-chain and ring form. Carbohydrates are aldehydes or ketones, with many hydroxyl groups attached, that can exist as straight chains or rings. Carbohydrates are the most abundant biological molecules, and fill numerous roles, such as the storage and transport of energy (starch, glycogen) and structural components (cellulose in plants, chitin in animals). The basic carbohydrate units are called monosaccharides and include galactose, fructose, and most importantly glucose.
An agarose gel in tray used for gel electrophoresis Agarose is a polysaccharide, generally extracted from certain red seaweed. It is a linear polymer made up of the repeating unit of agarobiose, which is a disaccharide made up of D-galactose and 3,6-anhydro-L-galactopyranose.Agar at lsbu.ac.uk Water Structure and Science Agarose is one of the two principal components of agar, and is purified from agar by removing agar's other component, agaropectin.
Glucose is hydrolyzed on fully folded protein and the mannose moieties are hydrolyzed by ER and Golgi-resident mannosidases. Typically, mature human glycoproteins only contain three mannose residues buried under sequential modification by GlcNAc, galactose, and sialic acid. This is important, as the innate immune system in mammals is geared to recognise exposed mannose residues. This activity is due to the prevalence of mannose residues, in the form of mannans, on the surfaces of yeasts.
The asialoglycoprotein receptors are lectins which bind asialoglycoprotein and glycoproteins from which a sialic acid has been removed to expose galactose residues. The receptors, which are located on liver cells, remove the target glycoproteins from circulation. The asialoglycoprotein receptor has been demonstrated to have high expression on the surface of hepatocytes , several human carcinoma cell lines and liver cancers. It is also weakly expressed by glandular cells of the gallbladder and the stomach.
Third-generation Glycoazodyes are synthesized using amino sugars such as 6-amino-6-deoxy-D-galactose or 6' amino-6'-deoxylactose. The point of the amide bond is controlled by protecting the alcohol groups on the sugar and allowing the free amine to react. The point of the ester group is controlled by choosing a azo dye with a different alcohol group position. Either the dye or the sugar is reacted with succinic anhydride.
Mannan chain backbones are synthesized by cellulose synthase-like protein family A (CSLA) and possibly enzymes in cellulose synthase-like protein family D (CSLD). Mannan synthase, a particular enzyme in CSLA, is responsible for the addition of mannose units to the backbone. The galactose side-chains of some mannans are added by galactomannan galactosyltransferase. Acetylation of mannans is mediated by a mannan O-acetyltransferase, however, this enzyme has not been definitively identified.
Lactose, the disaccharide sugar component of all milk, must be cleaved in the small intestine by the enzyme lactase, in order for its constituents, galactose and glucose, to be absorbed. Lactose intolerance is a condition in which people have symptoms due to not enough of the enzyme lactase in the small intestines. Those affected vary in the amount of lactose they can tolerate before symptoms develop. These may include abdominal pain, bloating, diarrhea, gas, and nausea.
Prepro-GAOX (galactose oxidase with signal sequence) is processed twice by proteolytic cleavage in the leader sequence to form the mature GAOX peptide (pro-GAOX). The first cleavage removes a sequence of 24 amino acids by signal peptidase. The second cleavage removes another sequence of 17 amino acids. The covalent linkage between Tyr272 and Cys228 forms after pro-GAOX has been made. The occurrence of this modification does not seem to require any other “helper” proteins.
O-fucosylation on EGF domains occurs between the second and third conserved cysteine residues in the protein sequence. Once the core O-fucose has been added, it is often elongated by addition of GlcNAc, galactose and sialic acid. Notch is an important protein in development, with several EGF domains that are O-fucosylated. Changes in the elaboration of the core fucose determine what interactions the protein can form, and therefore which genes will be transcribed during development.
These include lactose, the predominant sugar in milk, which is a glucose-galactose disaccharide, and sucrose, another disaccharide which is composed of glucose and fructose. Glucose is also added onto certain proteins and lipids in a process called glycosylation. This is often critical for their functioning. The enzymes that join glucose to other molecules usually use phosphorylated glucose to power the formation of the new bond by coupling it with the breaking of the glucose-phosphate bond.
Later on an important center focused on nutrition and gut pathophysiology was established by Bertil Linquist in Lund, Sweden. This was the first place in which glucose-galactose malabsorption was reported. Pediatric gastroenterology centers in London contributed greatly to this field and hepatology by helping and recognizing multiple doctors with their investigations. An example is Tom Macdonald, who concentrated his immunological research on gastroenterological diseases in children and the use of a fetal intestinal organ culture model.
The microbial arabinogalactan is a major structural component of the mycobacterial cell wall. Both the arabinose and galactose exist solely in the furanose configuration. The galactan portion of microbial arabinogalactan is linear, consisting of approximately 30 units with alternating β-(1-5) and β-(1-6) glycosidic linkages. The arabinan chain, which consists of about 30 residues, is attached at three branch points within the galactan chain, believed to be at residues 8, 10 and 12.
A symporter uses the downhill movement of one solute species from high to low concentration to move another molecule uphill from low concentration to high concentration (against its concentration gradient). Both molecules are transported in the same direction. An example is the glucose symporter SGLT1, which co-transports one glucose (or galactose) molecule into the cell for every two sodium ions it imports into the cell. This symporter is located in the small intestines, heart, and brain.
Recently, the roles of active site residues in human galactokinase have become understood. Asp-186 abstracts a proton from C1-OH of α-D-galactose, and the resulting alkoxide nucleophile attacks the γ-phosphorus of ATP. A phosphate group is transferred to the sugar, and Asp-186 may be deprotonated by water. Nearby Arg-37 stabilizes Asp-186 in its anionic form and has also been proven to be essential to galactokinase function in point mutation experiments.
Remarkably, the difference between the A and B glycosyltransferase enzymes is only four amino acids. The O allele lacks both enzymatic activities because of the frame shift caused by a deletion of guanine-258 in the gene which corresponds to a region near the N-terminus of the protein. This results in a frameshift and translation of an almost entirely different protein. This mutation results in a protein unable to modify oligosaccharides which end in fucose linked to galactose.
Chemoattracttants to Trg include ribose and galactose with phenol as a chemorepellent. Tap and Tsr recognize dipeptides and serine as chemoattractants, respectively. Chemoattractants or chemorepellents bind MCPs at its extracellular domain; an intracellular signaling domain relays the changes in concentration of these chemotactic ligands to downstream proteins like that of CheA which then relays this signal to flagellar motors via phosphorylated CheY (CheY-P). CheY-P can then control flagellar rotation influencing the direction of cell motility.
For instance, in an aquatic system consisting of a primary producer, a mineral resource, and an herbivore, researchers found that patterns of equilibrium, cycling, and extinction of populations could be qualitatively described with a simple nonlinear model with a Hopf Bifurcation.Gregor F. Fussmann, Stephen P. Ellner, Kyle W. Shertzer, and Nelson G. Hairston Jr. Crossing the Hopf Bifurcation in a Live Predator–Prey System. Science. 17 November 2000: 290 (5495), 1358–1360. Galactose utilization in budding yeast (S.
Ricin B chain binds complex carbohydrates on the surface of eukaryotic cells containing either terminal N-acetylgalactosamine or beta-1,4-linked galactose residues. In addition, the mannose-type glycans of ricin are able to bind to cells that express mannose receptors. RTB has been shown to bind to the cell surface on the order of 106-108 ricin molecules per cell surface. The profuse binding of ricin to surface membranes allows internalization with all types of membrane invaginations.
Host mucin cells have galactose and N-acetylgalactosamine which serve as the binding sites for these Gal/GalNac lectins. These lectins are a huge area of interest for scientists, as the association between these glycoproteins could potentially be a target for drug therapy. Once the trophozoites begin to aggregate, cyst differentiation is initiated by intracellular rearrangement which leads to cell rounding and cellular compaction. This rearrangement of the actin cytoskeleton seems to be crucial in differentiation to cysts.
The second activity is restricted to lactating mammary tissues where the enzyme forms a heterodimer with alpha-lactalbumin to catalyze UDP-galactose + D-glucose <=> UDP + lactose. The two enzymatic forms result from alternate transcription initiation sites and post-translational processing. Two transcripts, which differ only at the 5' end, with approximate lengths of 4.1 kb and 3.9 kb encode the same protein. The longer transcript encodes the type II membrane- bound, trans-Golgi resident protein involved in glycoconjugate biosynthesis.
First-generation Glycoazodyes are synthesized using glucose, galactose or lactose as the sugar group. The point of esterification is controlled by selectively protecting alcohol groups on the sugar, or by choosing an azo dye with a different alcohol group position. Either the dye or the sugar group can be succinylated by reacting a free alcohol group with succinic anhydride. The resulting hemisuccinate then reacts with a free alcohol group on either the dye or the sugar.
The pods of Parkia pendula contain anywhere from 15 to 34 seeds. They have an elliptical shape and are 0.9 to 1 cm in length and 0.4 to 0.5 cm in width. Seeds weigh between 0.06 and 0.11 grams and there are said to be 9848 to 10100 seeds per kilogram of fruit pods. The seed pod gum of Parkia pendula is extremely sticky due to a high concentration of sugars such as galactose and arabinose.
Halostagnicola larsenii is a halophilic, neutrophilic, chemo-organotroph and uses oxygen as its terminal electron acceptor. H. larsenii can utilize a variety of carbohydrates such as fructose, glycerol, lactose, glucose, arabinose, acetate, ribose, starch, maltose, galactose, ribose, xylose, glutamate, and propionate as substrates for growth. Growth substrates were determined through the use of the isolation medium, which contained the substrate being tested along with yeast extract. Additionally, H. larsenii undergoes assimilatory nitrate reduction to nitrite to ammonia.
Two screening tests are used to screen infants affected with galactosemia—the Beutler's test and the Hill test. The Beutler's test screens for galactosemia by detecting the level of enzyme of the infant. Therefore, the ingestion of formula or breast milk does not affect the outcome of this part of the NBS, and the NBS is accurate for detecting galactosemia prior to any ingestion of galactose. Duarte galactosemia is a milder form of classical galactosemia and usually has no long term side effects.
ST6GALNAC4 is a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. The encoded protein prefers glycoproteins rather than glycolipids as substrates and shows restricted substrate specificity, utilizing only the trisaccharide sequence Neu5Ac-alpha-2,3-Gal-beta-1,3-GalNAc. In addition, it is involved in the synthesis of ganglioside GD1A from GM1B. The enzyme is normally found in the Golgi apparatus but can be proteolytically processed to a soluble form.
Lactose is a disaccharide found in animal milk. It consists of a molecule of D-galactose and a molecule of D-glucose bonded by beta-1-4 glycosidic linkage. A carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where m may be different from n). However, not all carbohydrates conform to this precise stoichiometric definition (e.g.
Electrical and electrochemical detection are easily adapted for portability and miniaturization, especially in comparison to optical detection. In amperometric biosensors, an enzyme- catalyzed redox reaction causes a redox electron current that is measured by a working electrode. Amperometric biosensors have been used in bio-MEMS for detection of glucose, galactose, lactose, urea, and cholesterol, as well as for applications in gas detection and DNA hybridization. In potentiometric biosensors, measurements of electric potential at one electrode are made in reference to another electrode.
Binding of the ligand causes a conformational change that is transmitted across the membrane to the cytoplasmic activation domain. Environmental diversity gives rise to diversity in bacterial signalling receptors, and consequently there are many genes encoding MCPs. For example, there are four well-characterised MCPs found in Escherichia coli: Tar (taxis towards aspartate and maltose, away from nickel and cobalt), Tsr (taxis towards serine, away from leucine, indole and weak acids), Trg (taxis towards galactose and ribose) and Tap (taxis towards dipeptides).
C. albidus var. albidus is a variety of C. albidus that has been considered unique. It differs from C. neoformans because of its ability to assimilate lactose, but not galactose. This species is also considered unique because its strains have a maximum temperature range from between 25 and 37°C. This is important because it violates van Uden’s rule, which states that the yeast strains of a particular species cannot have their maximum growth temperature vary by more than 5°C.
S. boulardii was characterized as a species separate from S. cerevisiae because it does not digest galactose and does not undergo sporulation. Its genomic sequence, however, defines it as a clade under S. cerevisiae, closest to those found in wine. Like S. cerevisiae, it has 16 chromosomes, a 2-micron circle plasmid, and is diploid with genes for both mating types, MATa and MATα. Notably, the MATa locus consistently contains some likely disabling mutations relative to spore-forming S. cerevisiae.
In completing his Ph.D. in the Graduate School of Ohio State University, Calvin Buehler published his dissertation in 1922 titled The Oxidation of Lactose, Glucose, and Galactose by Means of Neutral and Alkaline Potassium Permanganate. His research was conducted under Dr. W. L. Evans and worked alongside C.W. Kreger. Over the span of his career, Buehler would publish over forty-two scholarly articles. Buehler was the co-author of the book Survey of Organic Syntheses, published by Wiley-Interscience publications in 1970.
The chvE-gguAB gene in Agrobacterium tumefaciens encodes glucose and galactose importers that are also associated with virulence. Transporters are extremely vital in cell survival such that they function as protein systems that counteract any undesirable change occurring in the cell. For instance, a potential lethal increase in osmotic strength is counterbalanced by activation of osmosensing ABC transporters that mediate uptake of solutes. Other than functioning in transport, some bacterial ABC proteins are also involved in the regulation of several physiological processes.
211; Nagda and Deshmukh, "Hemagglutination Pattern of Galactose Specific Lectin From Pedilanthus tithymaloides in Diabetes Mellitus," Indian Journal of Experimental Biology, 1998, 426-428. In folk medicine, tea has been brewed from the leaves which has been used to treat asthma, persistent coughing, laryngitis, mouth ulcers, and venereal disease. Tea brewed from the root has been used as an abortifacient. The latex has been used topically to treat calluses, ear ache, insect stings, ringworm, skin cancer, toothache, umbilical hernias, and warts.
Since an inversion occurs at the anomeric center, the reaction leads to β-O-glycosides (when using α-trichloroacetimidates). The trichloroacetimidate method often produces sterically uniform glycosides under mild reaction conditions in very good yields. Octaacetyl-Trehalose Thioacetic acid reacts with acetyl-protected α-galactosyl trichloroacetimidate even without additional acid catalysis to thioglycoside, from which (after cleavage of the protective groups) 1-thio-β- D-galactose is easily accessible, which is useful for the separation of racemates of amino acids.A. Jegorov et al.
The specificity of the H antigen is determined by the sequence of oligosaccharides. More specifically, the minimum requirement for H antigenicity is the terminal disaccharide fucose-galactose, where the fucose has an alpha(1-2)linkage. This antigen is produced by a specific fucosyl transferase (Galactoside 2-alpha-L-fucosyltransferase 2) that catalyzes the final step in the synthesis of the molecule. Depending upon a person's ABO blood type, the H antigen is converted into either the A antigen, B antigen, or both.
Chondroitin sulfate nb R1, R2, R3 Hyaluronan (-4GlcUAβ1-3GlcNAcβ1-)n Glycosaminoglycans (GAGs) or mucopolysaccharides are long linear polysaccharides consisting of repeating disaccharide (double sugar) units. Except for keratan, the repeating unit consists of an amino sugar, along with a uronic sugar or galactose. Because GAGs are highly polar and attract water, they are used in the body as a lubricant or shock absorber. Mucopolysaccharidoses are a group of metabolic disorders in which abnormal accumulations of glycosaminoglycans occur because of enzyme deficiencies.
The epitope XNAs target is an α-linked galactose moiety, Gal-α-1,3Gal (also called the α-Gal epitope), produced by the enzyme α-galactosyl transferase. Most non- primates contain this enzyme thus, this epitope is present on the organ epithelium and is perceived as a foreign antigen by primates, which lack the galactosyl transferase enzyme. In pig to primate xenotransplantation, XNAs recognize porcine glycoproteins of the integrin family. The binding of XNAs initiate complement activation through the classical complement pathway.
Ascorbic acid efflux by embryo of dicots plants is a well-established mechanism of iron reduction, and a step obligatory for iron uptake. All plants synthesize ascorbic acid. Ascorbic acid functions as a cofactor for enzymes involved in photosynthesis, synthesis of plant hormones, as an antioxidant and also regenerator of other antioxidants. Plants use multiple pathways to synthesize vitamin C. The major pathway starts with glucose, fructose or mannose (all simple sugars) and proceeds to L-galactose, L-galactonolactone and ascorbic acid.
Fanconi–Bickel syndrome is a form of glycogen storage disease. It is also known for Guido Fanconi and Horst Bickel, who first described it in 1949. It is associated with GLUT2, a glucose transport protein which, when functioning normally, allows glucose to exit several tissues, including the liver, nephrons, and enterocytes of the intestines, and enter the blood. The syndrome results in hepatomegaly secondary to glycogen accumulation, glucose and galactose intolerance, fasting hypoglycaemia, a characteristic proximal tubular nephropathy and severe short stature.
Uracil's use in the body is to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates. Uracil serves as allosteric regulator and coenzyme for reactions in animals and in plants. UMP controls the activity of carbamoyl phosphate synthetase and aspartate transcarbamoylase in plants, while UDP and UTP requlate CPSase II activity in animals. UDP- glucose regulates the conversion of glucose to galactose in the liver and other tissues in the process of carbohydrate metabolism.
Lactulose is used in the treatment of chronic constipation in patients of all ages as a long- term treatment. The dosage of lactulose for chronic idiopathic constipation is adjusted depending on the constipation severity and desired effect, from a mild stool softener to causing diarrhea. Dosage is reduced in case of galactosemia, as most preparations contain the monosaccharide galactose due to its synthesis process. Lactulose may be used to counter the constipating effects of opioids, and in the symptomatic treatment of hemorrhoids as a stool softener.
Microcystis floating colonies in an Erlenmeyer flask. As the etymological derivation implies, Microcystis is characterized by small cells (a few micrometers in diameter), possessing gas filled vesicles (also lacking individual sheaths). The cells are usually organized into colonies (macroscopic aggregations of which are visible with the naked eye) that begin in a spherical shape, losing coherence to become perforated or irregularly shaped over time. These colonies are bound by a thick mucilage composed of complex polysaccharide compounds, including xylose, mannose, glucose, fucose, galactose, rhamnose, among other compounds.
The sweetness of lactose is 0.2 to 0.4, relative to 1.0 for sucrose. For comparison, the sweetness of glucose is 0.6 to 0.7, of fructose is 1.3, of galactose is 0.5 to 0.7, of maltose is 0.4 to 0.5, of sorbose is 0.4, and of xylose is 0.6 to 0.7. When lactose is completely digested in the small intestine, its caloric value is 4 kcal/g, or the same as that of other carbohydrates. However, lactose is not always fully digested in the small intestine.
Lactase can be purchased as a food supplement, and is added to milk to produce "lactose- free" milk products. Lactase (also known as lactase-phlorizin hydrolase, or LPH), a part of the β-galactosidase family of enzymes, is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers. Lactase is present predominantly along the brush border membrane of the differentiated enterocytes lining the villi of the small intestine. In humans, lactase is encoded by the LCT gene.
While the details of the mechanism are uncertain, the stereochemical retention is achieved off a double displacement reaction. Studies of E. coli lactase have proposed that hydrolysis is initiated when a glutamate nucleophile on the enzyme attacks from the axial side of the galactosyl carbon in the β-glycosidic bond. The removal of the D-glucose leaving group may be facilitated by Mg-dependent acid catalysis. The enzyme is liberated from the α-galactosyl moiety upon equatorial nucleophilic attack by water, which produces D-galactose.
The β-galactosidase assay is used frequently in genetics, molecular biology, and other life sciences. An active enzyme may be detected using artificial chromogenic substrate 5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside, X-gal. β-galactosidase will cleave the glycosidic bond in X-gal and form galactose and 5-bromo-4-chloro-3-hydroxyindole which dimerizes and oxidizes to 5,5'-dibromo-4,4'-dichloro-indigo, an intense blue product that is easy to identify and quantify. It is used for example in blue white screen.
DTDP-3-amino-3,6-dideoxy-alpha-D-galactopyranose 3-N-acetyltransferase (, FdtC, dTDP-D-Fucp3N acetylase) is an enzyme with systematic name acetyl- CoA:dTDP-3-amino-3,6-dideoxy-alpha-D-galactopyranose 3-N-acetyltransferase. This enzyme catalyses the following chemical reaction : acetyl-CoA + dTDP-3-amino-3,6-dideoxy-alpha-D-galactopyranose \rightleftharpoons CoA + dTDP-3-acetamido-3,6-dideoxy-alpha-D-galactopyranose dTDP-3-acetamido-3,6-dideoxy-alpha-D-galactose is a component of the glycan chain of the crystalline bacterial cell surface layer protein of Aneurinibacillus thermoaerophilus.
In addition to cellulose, β-glucosidases can cleave xylose, mannose and galactose. In white-rot fungi such as Phanerochaete chrysosporium, expression of manganese-peroxidase is induced by the presence of manganese, hydrogen peroxide and lignin, while laccase is induced by availability of phenolic compounds. Production of lignin-peroxidase and manganese-peroxidase is the hallmark of basidiomycetes and is often used to assess basidiomycete activity, especially in biotechnology applications. Most white-rot species also produce laccase, a copper-containing enzyme that degrades polymeric lignin and humic substances.
Infants with DG are generally diagnosed in follow-up to a positive newborn screening (NBS) result for galactosemia. Specifically, dried blood spots collected for NBS from infants with DG may show low (but generally non-zero) GALT enzyme activity, elevated galactose metabolite levels, or both. DG can also be identified by genetic testing. Of note, not all NBS tests for galactosemia are designed to detect DG so infants with DG born in one jurisdiction may be detected while those born in another may not.
These enzymes are responsible for something called a "fringe effect" on notch signaling. If Fringe adds a GlcNAc to the O-fucose sugar then the subsequent addition of a galactose and sialic acid will occur. In the presence of this tetrasaccharide, notch signals strongly when it interacts with the Delta ligand, but has markedly inhibited signaling when interacting with the Jagged ligand. The means by which this addition of sugar inhibits signaling through one ligand, and potentiates signaling through another is not clearly understood.
This gene encodes a subunit of the asialoglycoprotein receptor. This receptor is a transmembrane protein that plays a critical role in serum glycoprotein homeostasis by mediating the endocytosis and lysosomal degradation of glycoproteins with exposed terminal galactose or N-acetylgalactosamine residues. The asialoglycoprotein receptor may facilitate hepatic infection by multiple viruses including hepatitis B, and is also a target for liver-specific drug delivery. The asialoglycoprotein receptor is a hetero-oligomeric protein composed of major and minor subunits, which are encoded by different genes.
Figure 1: Biosynthesis of α-tomatine (26) and other steroidal glycoalkaloids in Solanaceae species. Figure 2: Mechanism of membrane disruption by glycoalkaloids Alpha-tomatine (α-tomatine) belongs to the compound group steroidal glycoalkaloids. These compounds consist of an aglycon, which is a cholesterol derivative, and a carbohydrate chain, which in the case of α-tomatine consists of two d-glucose units, a d-galactose unit, and a d-xylose unit. In α-tomatine, the tetrasaccharide called lycotetraose is attached to the O-3 of the steroidal aglycone.
Glycosyltransferases that use non-nucleotide donors such as dolichol or polyprenol pyrophosphate are non-Leloir glycosyltransferases. Mammals use only 9 sugar nucleotide donors for glycosyltransferases: UDP-glucose, UDP-galactose, UDP-GlcNAc, UDP-GalNAc, UDP- xylose, UDP-glucuronic acid, GDP-mannose, GDP-fucose, and CMP-sialic acid. The phosphate(s) of these donor molecules are usually coordinated by divalent cations such as manganese, however metal independent enzymes exist. Many glycosyltransferases are single-pass transmembrane proteins, and they are usually anchored to membranes of Golgi apparatusTransferases in Membranome database.
Keratan sulfate I (KSI) is N -linked via a high mannose type precursor oligosaccharide. Keratan sulfate II (KSII) and keratan sulfate III (KSIII) are O-linked, with KSII linkages identical to that of mucin core structure, and KSIII linked to a 2-O mannose. Elongation of the keratan sulfate polymer occurs through the glycosyltransferase addition of Gal and GlcNAc. Galactose addition occurs primarily through the β-1,4-galactosyltransferase enzyme (β4Gal-T1) while the enzymes responsible for β-3-Nacetylglucosamine have not been clearly identified.
The vast majority of animals and plants are able to synthesize vitamin C, through a sequence of enzyme-driven steps, which convert monosaccharides to vitamin C. Yeasts do not make -ascorbic acid but rather its stereoisomer, erythorbic acid. In plants, this is accomplished through the conversion of mannose or galactose to ascorbic acid. In animals, the starting material is glucose. In some species that synthesize ascorbate in the liver (including mammals and perching birds), the glucose is extracted from glycogen; ascorbate synthesis is a glycogenolysis-dependent process.
As a multimer, alpha-lactalbumin strongly binds calcium and zinc ions and may possess bactericidal or antitumor activity. A folding variant of human alpha-lactalbumin that may form in acidic environments such as the stomach, called HAMLET, probably induces apoptosis in tumor and immature cells. The corresponding folding dynamics of alpha- lactalbumin is thus highly unusual. When formed into a complex with Gal-T1, a galactosyltransferase, α-lactalbumin, enhances the enzyme's affinity for glucose by about 1000 times, and inhibits the ability to polymerise multiple galactose units.
In enzymology, a glucosaminylgalactosylglucosylceramide beta- galactosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-galactose + N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D- galactosyl-(1->4)-beta-D- glucosyl-(11)-ceramide \rightleftharpoons UDP + beta-D-galactosyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D- galactosyl-(1->4)-beta-D-glucosyl-(11)-ceramide The 3 substrates of this enzyme are UDP-galactose, N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D- galactosyl-(1->4)-beta-D-, and glucosyl-(11)-ceramide, whereas its 3 products are UDP, beta-D-galactosyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D-, and galactosyl-(1->4)-beta-D-glucosyl-(11)-ceramide. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:N-acetyl-beta-D- glucosaminyl-(1->3)-beta-D-galactosyl- (1->4)-beta-D-glucosylceramide 3-beta- D-galactosyltransferase. Other names in common use include uridine, diphosphogalactose-acetyl-glucosaminylgalactosylglucosylceramide, galactosyltransferase, GalT-4, paragloboside synthase, glucosaminylgalactosylglucosylceramide 4-beta-galactosyltransferase, lactotriaosylceramide 4-beta-galactosyltransferase, UDP-galactose:N-acetyl-D- glucosaminyl-1,3-D-galactosyl-1,4-D-, glucosylceramide beta-D- galactosyltransferase, and UDP-Gal:LcOse3Cer(beta 1-4)galactosyltransferase.
For fuel ethanol production, complete metabolism of complex combinations of sugars in E. coli by synthetic biocatalysts is necessary. Deletion of the methylglyoxal synthase gene in E. coli increases fermentation rate of ethanogenic E. coli by promoting the co-metabolism of sugar mixtures containing the five principal sugars found in biomass (glucose, xylose, arabinose, galactose, and mannose). This suggests that MGS production of methylglyoxal plays a role in controlling expression of sugar-specific transporters and catabolic genes in native E.coli. MGS also has industrial importance in the production of lactate, hydroxyacetone (acetol), and 1,2-propandiol.
UDP-galactose. In nucleotide sugar metabolism a group of biochemicals known as nucleotide sugars act as donors for sugar residues in the glycosylation reactions that produce polysaccharides. They are substrates for glycosyltransferases. The nucleotide sugars are also intermediates in nucleotide sugar interconversions that produce some of the activated sugars needed for glycosylation reactions. Since most glycosylation takes place in the endoplasmic reticulum and golgi apparatus, there are a large family of nucleotide sugar transporters that allow nucleotide sugars to move from the cytoplasm, where they are produced, into the organelles where they are consumed.
This classification is available on the CAZy web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes. Glycoside hydrolase family 27 together with family 31 and the family 36 alpha- galactosidases form the glycosyl hydrolase clan GH-D, a superfamily of alpha- galactosidases, alpha-N-acetylgalactosaminidases, and isomaltodextranases which are likely to share a common catalytic mechanism and structural topology. Alpha-galactosidase () (melibiase) catalyzes the hydrolysis of melibiose into galactose and glucose. In man, the deficiency of this enzyme is the cause of Fabry's disease (X-linked sphingolipidosis).
P22TSP recognizes the O-antigen polysaccharide of LPS serotypes A, B, or D1. The serotypes correspond to species S. Typhimurium, S. Enteritidis, and S. Paratyphi A. These carbohydrates share the same main chain trisaccharide repeating unit alpha-D- mannose-(1—4)-alpha-L-rhamnose-(1—3)-alpha-D-galactose-(1—2), but each have a different 2,6-dideoxyhexose substituent at C-3 of the mannose. In vivo, P22TSP binds as a homotrimer and one phage particle can carry up to 6 tailspikes. P22TSP can bind multivalently, leading to an essentially irreversible attachment.
Many adult humans lack the lactase enzyme, which has the same function of beta-gal, so they are not able to properly digest dairy products. Beta-galactose is used in such dairy products as yogurt, sour cream, and some cheeses which are treated with the enzyme to break down any lactose before human consumption. In recent years, beta-galactosidase has been researched as a potential treatment for lactose intolerance through gene replacement therapy where it could be placed into the human DNA so individuals can break down lactose on their own.
The positions of those four hydroxyls are exactly reversed in the Fischer diagram of -glucose. - and -glucose are two of the 16 possible aldohexoses; the other 14 are allose, altrose, galactose, gulose, idose, mannose, and talose, each with two enantiomers, “-” and “-”. It is important to note that the linear form of glucose makes up less than 0.02% of the glucose molecules in a water solution. The rest is one of two cyclic forms of glucose that are formed when the hydroxyl group on carbon 5 (C5) bonds to the aldehyde carbon 1 (C1).
Aldose reductase catalyzes the NADPH-dependent conversion of glucose to sorbitol, the first step in polyol pathway of glucose metabolism. The second and last step in the pathway is catalyzed by sorbitol dehydrogenase, which catalyzes the NAD-linked oxidation of sorbitol to fructose. Thus, the polyol pathway results in conversion of glucose to fructose with stoichiometric utilization of NADPH and production of NADH. ;glucose + NADPH + H+ \rightleftharpoons sorbitol + NADP+ Galactose is also a substrate for the polyol pathway, but the corresponding keto sugar is not produced because sorbitol dehydrogenase is incapable of oxidizing galactitol.
Capsulan has been found to be mostly carbohydrate (70%) with some protein and sulfur. The main sugars making up the carbohydrate are galactose and glucose while other sugars such as xylose, arabinose and mannose are also present in smaller quantities. Myklestad, 1999, Phytoplankton extracellular production and leakage with considerations on the polysaccharide accumulation Sugar acids are common in plant and algal polysacchride but there is disagreement in the literature concerning capsulan's sugar acid content. Kurano claims that capsulan contains none, while Myklestad maintains that both galacturonic and glucuronic acids are present.
Albeit intrauterine insemination (IUI) might circumvent ASA present in the cervical mucus, in a study comprising 119 IUI, no live pregnancy was reported, suggesting involvement of other mechanisms of ASA. Since ASA are usually bound to sperm surface antigens with high affinity, ordinary wash-up used before ICSI is not effective. Thus, some authors recommend treatment of sperm with chymotrypsin/galactose to cleave ASA molecules. However, this method has not been adopted by clinicians as some concerns exist regarding a possible negative impact of this digestive enznyme on sperm surface receptors involved in fertilization.
Glucosylceramide beta-1,4-galactosyltransferase (, lactosylceramide synthase, uridine diphosphate-galactose:glucosyl ceramide beta 1-4 galactosyltransferase, UDP-Gal:glucosylceramide beta1->4galactosyltransferase, GalT-2, UDP-galactose:beta-D-glucosyl-(1<->1)-ceramide beta-1,4-galactosyltransferase) is an enzyme with systematic name UDP-alpha-D- galactose:beta-D-glucosyl-(1<->1)-ceramide 4-beta-D-galactosyltransferase. This enzyme catalyses the following chemical reaction : UDP-alpha-D-galactose + beta-D-glucosyl-(1<->1)-ceramide \rightleftharpoons UDP + beta-D- galactosyl-(1->4)-beta-D-glucosyl-(1<->1)-ceramide Involved in the synthesis of several different major classes of glycosphingolipids.
Fructo-oligosaccharides (FOS), which are found in many vegetables, are short chains of fructose molecules. They differ from fructans such as inulin, which as polysaccharides have a much higher degree of polymerization than FOS and other Oligiosaccharides, but like inulin and other fructans, they are considered soluble dietary fibre. Galactooligosaccharides (GOS), which also occur naturally, consist of short chains of galactose molecules. These compounds cannot be digested in the human small intestine, and instead pass through to the large intestine, where they promote the growth of Bifidobacteria, which are beneficial to gut health.
When GalR binds as a dimer to the -60 site only, the promoter PG2 is activated, not repressed, allowing basal levels of GalE to be produced. In this state, the PG1 promoter is inactivated through interactions with the alpha subunit of RNA polymerase. Activity of this repressor protein is controlled based on the levels of D-galactose in the cell. Increased levels of this sugar inhibit the activity of the repressor by binding allosterically, resulting in a conformational change of the protein, which suppresses its interactions with RNA polymerase and DNA.
Galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase 2 is an enzyme that in humans is encoded by the B3GAT2 gene. The product of this gene is a transmembrane protein belonging to the glucuronyltransferase family, and catalyzes the transfer of a beta-1,3 linked glucuronic acid to a terminal galactose in different glycoproteins or glycolipids containing a Gal- beta-1-4GlcNAc or Gal-beta-1-3GlcNAc residue. The encoded protein is involved in the synthesis of the human natural killer-1 (HNK-1) carbohydrate epitope, a sulfated trisaccharide implicated in cellular migration and adhesion in the nervous system.
Also, the idea of Xylitol being a sweetener option which does not serve as fuel for oral bacteria is considered to be the healthier alternative than sucrose (table sugar), fructose, lactose, galactose products. While these considerations may not reverse any conditions in health, they are more so preventative, and do not further the consequential events such as dental caries, malodorous breath, excessive plaque and gingivitis conditions. Erythritol may have greater protective action than xylitol and sorbitol. However, this research is industry funded and not as comprehensive as the research on xylitol.
Sporulation occurs rapidly at pH 4.0-6.5 and a combination of low temperature () and high glucose concentration can increase the size of conidia. Treatment of T. roseum with colchicine increases the number of nuclei in conidia, growth rate, and biosynthetic activities. There are a variety of sugars that T. roseum can utilize including D-fructose, sucrose, maltose, lactose, raffinose, D-galactose, D-glucose, arabinose, and D-mannitol. Good growth also occurs in the presence of various amino acids including L-methionine, L-isoleucine, L-tryptophan, L-alanine, L-norvaline, and L-norleucine.
Volkensin is a eukaryotic ribosome-inactivating protein found in the Adenia volkensii plant. It is a glycoprotein with two subunits A and B. A subunit is linked to B subunit with disulfide bridges and non-covalent bonds. B subunit is responsible for binding to the galactosyl-terminated receptors on the cell membrane that allows the entry the A subunit of the toxin into the cell, which performs the inhibitory function. Volkensin is a galactose specific lectin that can inhibit protein synthesis in whole cells and in cell-free lysates.
This protein can be included into the category of risin like toxins and it resembles modeccin, the toxin of Adenia digitata. Although very similar in composition, volkensin contains more cysteine residues and more than twice as much sugar than modeccin, due to high content of galactose and mannose. In addition, volkensin is able to inhibit protein synthesis at concentrations 10 times lower than required for modeccin. From gene sequencing analysis, volkensin was found to be coded by 1569-bp ORF, that is 523 amino acid residues without introns.
In terms of chemicals that influence fungal growth, the minimum growth inhibitory concentration of sorbic acid is 0.02–0.025% at a pH of 4.7 and 0.06–0.08% at a pH of 5.5. Thiamine, on the other hand, has been observed to accelerate fungal growth with the effect being co-metabolically enhanced in the presence of tyrosine, casein or zinc metal. In terms of carbon nutrition, maltose, acetic acid, oxalic acid and tartaric acid support little, if any, growth. However, glucose, fructose, sucrose, galactose, citric acid and malic acid all maintain fungal growth.
An important aspect of the Leishmania protozoan is its glycoconjugate layer of lipophosphoglycan (LPG). This is held together with a phosphoinositide membrane anchor, and has a tripartite structure consisting of a lipid domain, a neutral hexasaccharide, and a phosphorylated galactose-mannose, with a termination in a neutral cap. Not only do these parasites develop postphlebotomus digestion, but it is also thought to be essential to oxidative bursts, thus allowing passage for infection. Characteristics of intracellular digestion include an endosome fusing with a lysosome, releasing acid hydrolases which degrade DNA, RNA, proteins and carbohydrates.
After birth, galactose-1-phosphate uridyltransferase (GALT) activity in the infant's blood is measured. GALT is regulated by a protein encoded on chromosome 9p, so irregular levels of GALT activity may indicate an underlying chromosomal abnormality. Abnormal results are followed by analysis of blood, skin, and inner cheek cells, typically via fluorescence in situ hybridization, which allows genetic counsellors to physically view the chromosomal composition of the cells. Analysis of more than one tissue type is necessary in order to determine if the tetrasomy is present in its mosaic form.
The N-terminal cysteine-rich domain is homologous to the ricin B chain and binds to sulphated sugar moieties, with particularly high affinity for N-Acetylgalactosamine and galactose residues sulphated at positions 3 and 4 of their pyranose rings. Other ligands include chondroitin sulfates A and B, as well as sulphated Lewisx and Lewisa structures. The mannose receptor is the only member of the family in which this domain is functional. The mannose receptor N-terminal cysteine-rich domain (pink) bound to its sulphated N-Acetylgalactosamine ligand (cyan).
PFK1 is the most important control site in the mammalian glycolytic pathway. This step is subject to extensive regulation since it is not only highly exergonic under physiological conditions, but also because it is a committed step – the first irreversible reaction unique to the glycolytic pathway. This leads to a precise control of glucose and the other monosaccharides galactose and fructose going down the glycolytic pathway. Before this enzyme's reaction, glucose-6-phosphate can potentially travel down the pentose phosphate pathway, or be converted to glucose-1-phosphate for glycogenesis.
The consensus is 5′-CGG-N-CCG-3′. One study explored the galactose-responsive upstream activation sequence (UAS), looking at the influence of proximity to this UAS for nucleosome positioning. Proximity to the UAS was chosen because deletions of DNA flanking the UAS left the nucleosome array unaltered, indicating that nucleosome positioning was not related to sequence-specific histone-DNA interactions. The role of specific regions of UAS was analyzed by inserting oligonucleotides with different binding properties, leading to the successful identification of a region responsible for the creation of an ordered array.
This event was shown to take place: in yeast during growth in galactose and inositol starvation; plants during environmental stress; in mammalian cells during LPS and interferon induction. Prior work has shown that certain characteristics of chromatin may contribute to the poised transcriptional state that allows for faster re-induction. These include: activity of specific transcription factors, retention of RNA polymerase II at the promoters of poised genes, activity of chromatin remodeling complexes, propagation of H3K4me2 and H3K36me3 histone modifications, occupancy of the H3.3 histone variant, as well as binding of nuclear pore components.
B. pseudomallei measures 2–5 μm in length and 0.4–0.8 μm in diameter and is capable of self-propulsion using flagella. The bacteria can grow in a number of artificial nutrient environments, especially betaine- and arginine- containing ones. In vitro, optimal proliferation temperature is reported around 40 °C in neutral or slightly acidic environments (pH 6.8–7.0). The majority of strains are capable of oxidation, not fermentation, of sugars without gas formation (most importantly, glucose and galactose; older cultures are reported to also metabolize maltose and starch).
Beta-galactoside alpha-2,6-sialyltransferase 1 is an enzyme that in humans is encoded by the ST6GAL1 gene. The protein encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. The encoded protein, which is normally found in the Golgi but which can be proteolytically processed to a soluble form, is involved in the generation of the cell-surface carbohydrate determinants and differentiation antigens HB-6, CDw75, and CD76. This protein is a member of glycosyltransferase family 29.
The aglycone (glycoside-free) portions of the saponins are termed sapogenins. The number of saccharide chains attached to the sapogenin/aglycone core can varygiving rise to another dimension of nomenclature (monodesmosidic, bidesmosidic, etc.)as can the length of each chain. A somewhat dated compilation has the range of saccharide chain lengths being 1–11, with the numbers 2–5 being the most frequent, and with both linear and branched chain saccharides being represented. Dietary monosaccharides such as D-glucose and D-galactose are among the most common components of the attached chains.
This rapid and violent type of rejection occurs within minutes to hours from the time of the transplant. It is mediated by the binding of XNAs (xenoreactive natural antibodies) to the donor endothelium, causing activation of the human complement system, which results in endothelial damage, inflammation, thrombosis and necrosis of the transplant. XNAs are first produced and begin circulating in the blood in neonates, after colonization of the bowel by bacteria with galactose moieties on their cell walls. Most of these antibodies are the IgM class, but also include IgG, and IgA.
Due to its complexity, the use of immunosuppressive drugs along with a wide array of approaches are necessary to prevent acute vascular rejection, and include administering a synthetic thrombin inhibitor to modulate thrombogenesis, depletion of anti-galactose antibodies (XNAs) by techniques such as immunoadsorption, to prevent endothelial cell activation, and inhibiting activation of macrophages (stimulated by CD4+ T cells) and NK cells (stimulated by the release of Il-2). Thus, the role of MHC molecules and T cell responses in activation would have to be reassessed for each species combo.
X-gal is an analog of lactose, and therefore may be hydrolyzed by the β-galactosidase enzyme which cleaves the β-glycosidic bond in D-lactose. X-gal, when cleaved by β-galactosidase, yields galactose and 5-bromo-4-chloro-3-hydroxyindole - 1. The latter then spontaneously dimerizes and is oxidized into 5,5'-dibromo-4,4'-dichloro-indigo - 2, an intensely blue product which is insoluble. X-gal itself is colorless, so the presence of blue-colored product may therefore be used as a test for the presence of active β-galactosidase.
In enzymology, a galactitol 2-dehydrogenase () is an enzyme that catalyzes the chemical reaction :galactitol + NAD+ \rightleftharpoons D-tagatose + NADH + H+ Thus, the two substrates of this enzyme are galactitol and NAD+, whereas its 3 products are D-tagatose, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is galactitol:NAD+ 2-oxidoreductase. This enzyme is also called dulcitol dehydrogenase. This enzyme participates in galactose metabolism.
All Blastobotrys species, including B. elegans, can grow on cellobiose, D-galactose, D-glucitol, D-glucose, D-mannitol, D-xylose, erythritol, glycerol, ribitol and trehalose. Therefore, when only looking at growth tests, it is very challenging to differentiate B. elegans from other Blastobotrys species. It is worth mentioning, that B. elegans also grows on adenine, arbutin, D-ribose, ethanol, ethylamine, glycine, isobutanol, lactose, n-Hexadecane, maltose, succinate and uric acid. It is unable to grow on D-arabinose, inositol, isoleucine, L-rhamnose, lactate, leucine, melezitose, melibiose, methyl-α-D-glucopyranoside, putrescine, raffinose and sucrose.
This classification is available on the CAZy web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes. Glycoside hydrolase family 36 together with family 31 and family 27 alpha-galactosidases form the glycosyl hydrolase clan GH-D, a superfamily of alpha-galactosidases, alpha-N-acetylgalactosaminidases, and isomaltodextranases which are likely to share a common catalytic mechanism and structural topology. Alpha- galactosidase () (melibiase) catalyzes the hydrolysis of melibiose into galactose and glucose. In man, the deficiency of this enzyme is the cause of Fabry's disease (X-linked sphingolipidosis).
The results show that amino acid levels remained relatively constant and in some cases even increased. > Thus, from these experiments it would appear that the loss of amino acids in > the lens when exposed to galactose is primarily due to the osmotic swelling > of the lens brought about by dulcitol [galactitol] retention. Galactosemic patients will also present with amino aciduria and galactitoluria (excessive levels of amino acids and galactitol in the urine). Osmotic swelling of the lens is also responsible for a reduction in electrolyte concentration during the initial vacuolar stage of galactosemic cataract.
Madurella mycetomatis has been identified in both soil and anthill samples, growing optimally at 37 ˚C, however can viably grow at up to 40 ˚C. This ability to grow at high temperatures is a feature that can be useful in identifying the fungus in culture. The fungus's ability, an inability, to break down various molecules can also be used to confirm its identity. Madurella mycetomatis is amylolytic yet is only weakly proteolytic, and has the ability to assimilate glucose, galactose, lactose and maltose, while unable to assimilate sucrose.
Ideal lipase growth conditions in Aspergillus wentii (100% lipase activity) occur under media supplemented with glucose of pH 6.0 at a temperature of 30 °C. Aspergillus wentii grown in mannitol media produces the second largest lipase yield (with 84% lipase activity). Lipase activity for Aspergillus wentii grown on fructose media produces just under 50% lipase activity while media supplemented with galactose, sucrose, lactose or maltose all yielded moderate lipase activity (20-37%). Aspergillus wentii strain NRRL 2001 spores were found to naturally produce glucose from hydrolyzing soluble starch.
The yeast cells, after growth on glucose-peptone-yeast extract broth culture for three days at , are egg-shaped to elongated, measuring 3–11 by 1–3.5 µm. They occur singly, in budding pairs, or as short pseudohyphae. The yeast can assimilate the following carbon sources: glucose, galactose, sucrose, L-arabinose, cellobiose, maltose, trehalose, lactose, D-xylose, rhamnose, isomaltulose, melibiose, melezitose; mannitol, sorbitol, glycerol, erythritol; N-acetyl glucosamine, 2-ketogluconate, α-methyl-D-glucoside, levulinate and glucosamine. The yeast grew at a variety of temperatures between , but no growth was observed at or .
The most primary metabolic activity of these microorganisms in sourdough is to produce acid and carbon dioxide; gas production is necessary for the dough leavening if yeast is not added. Lactobacillus pontis is capable of using fructose as a carbon source and convert stoichiometrically convert fructose to lactic acid and ethanol. However, when maltose is present, they use it chiefly as an electron acceptor, and fructose is reduced to mannitol. It can also metabolize ribose, D-raffinose, and gluconate, but cannot use glucose, L-arabinose, D-xylose, galactose, aesculin, lactose or melibiose.
On the microscopic level the cells appear globose to ovate and are capsulated. Occasionally the cells have been seen to create chains of four to five cells. When grown, it does not require vitamins, but its growth is weakened by the presence of ammonium sulfate. It is able to assimilate alpha-methyl-D- glucoside, Ca-2-keto-gluconate, cellobiose, D-arabinose, D-mannitol, D-sorbitol, D-xylose, galactose, glucose, K-5-keto-gluconate- K-gluconate, lactose, L-arabinose, L-rhamnose, maltose, melezitose, i-inositol, raffinose, salicin and trehalose.
For instance, besides glucose, sugar monomers in hemicelluloses can include the five-carbon sugars xylose and arabinose, the six-carbon sugars mannose and galactose, and the six-carbon deoxy sugar rhamnose. Hemicelluloses contain most of the D-pentose sugars, and occasionally small amounts of L-sugars as well. Xylose is in most cases the sugar monomer present in the largest amount, although in softwoods mannose can be the most abundant sugar. Not only regular sugars can be found in hemicellulose, but also their acidified form, for instance glucuronic acid and galacturonic acid can be present.
Since sIgA is a poor opsonin and activator of complement, simply binding a pathogen isn't necessarily enough to contain it—specific epitopes may have to be bound to sterically hinder access to the epithelium. Immune exclusion is a process of agglutinating polyvalent antigens or pathogens by crosslinking them with antibody, trapping them in the mucus layer, and/or clearing them peristaltically. The oligosaccharide chains of the component of IgA can associate with the mucus layer that sits atop epithelial cells. Clearance of IgA is mediated at least in part by asialoglycoprotein receptors, which recognizes galactose-terminating IgA N-glycans.
The active site of β-galactosidase catalyzes the hydrolysis of its disaccharide substrate via "shallow" (nonproductive site) and "deep" (productive site) binding. Galactosides such as PETG and IPTG will bind in the shallow site when the enzyme is in "open" conformation while transition state analogs such as L-ribose and D-galactonolactone will bind in the deep site when the conformation is "closed". The enzymatic reaction consists of two chemical steps, galactosylation (k2) and degalactosylation (k3). Galactosylation is the first chemical step in the reaction where Glu461 donates a proton to a glycosidic oxygen, resulting in galactose covalently bonding with Glu537.
Carbohydrates make up about 50% of the dry weight of green coffee beans. The carbohydrate fraction of green coffee is dominated by polysaccharides, such as arabinogalactan, galactomannan, and cellulose, contributing to the tasteless flavor of green coffee. Arabinogalactan makes up to 17% of dry weight of green coffee beans, with a molecular weight of 90 kDa to 200 kDa. It is composed of beta-1-3-linked galactan main chains, with frequent members of arabinose (pentose) and galactose (hexose) residues at the side chains comprising immunomodulating properties by stimulating the cellular defense system (Th-1 response) of the body.
TDP-4-oxo-6-deoxy-alpha-D-glucose-3,4-oxoisomerase (dTDP-3-dehydro-6-deoxy- alpha-D-galactopyranose-forming) (, dTDP-6-deoxy-hex-4-ulose isomerase, TDP-6-deoxy-hex-4-ulose isomerase, FdtA) is an enzyme with systematic name dTDP-4-dehydro-6-deoxy-alpha-D-glucopyranose:dTDP-3-dehydro-6-deoxy-alpha-D- galactopyranose isomerase. This enzyme catalyses the following chemical reaction : dTDP-4-dehydro-6-deoxy-alpha-D-glucopyranose \rightleftharpoons dTDP-3-dehydro-6-deoxy-alpha-D-galactopyranose The enzyme is involved in the biosynthesis of dTDP-3-acetamido-3,6-dideoxy-alpha-D-galactose.
The 1953 Science article mentioned above concluded that the reticular and regular collagenous materials contains the same four sugars – galactose, glucose, mannose, and fucose – but in a much greater concentration in the reticular than in the collagenous material. In a 1993 paper, the reticular fibers of the capillary sheath and splenic cord were studied and compared in the pig spleen by transmission electron microscopy. This paper attempted to reveal their components and the presence of sialic acid in the amorphous ground substance. Collagen fibrils, elastic fibers, microfibrils, nerve fibers, and smooth muscle cells were observed in the reticular fibers of the splenic cord.
The H gene of the ABO system encodes a fucosyltransferase that adds fucose to type 2 precursor substances on the surface of RBCs to make H antigen. The h allele is an amorphic form of the gene. If no further modifications are made to the H antigen, the person is type O. When the A gene product acts on the H antigen and adds an N-acetylgalactosamine, the A antigen results and the person is type A. When the B gene product acts on the H antigen to add a galactose, the B antigen results and the person is type B.
Fructose, or fruit sugar, is a simple ketonic monosaccharide found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into blood during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847.Dubrunfaut (1847) "Sur une propriété analytique des fermentations alcoolique et lactique, et sur leur application à l’étude des sucres" (On an analytic property of alcoholic and lactic fermentations, and on their application to the study of sugars), Annales de Chimie et de Physique, 21 : 169–178.
Galactosidases are enzymes (glycoside hydrolases) that catalyze the hydrolysis of galactosides into monosaccharides. Galactosides can be classified as either alpha or beta. If the galactoside is classified as an alpha-galactoside, the enzyme is called alpha-galactosidase, and is responsible for catalyzing the hydrolysis of substrates that contain α-galactosidic residues, such as glycosphingolipids or glycoproteins. On the other hand, if it is a beta- galactoside, it is called beta-galactosidase, and is responsible for breaking down the disaccharide lactose into its monosaccharide components, glucose and galactose Both varieties of galactosidase are categorized under the EC number 3.2.1.
Blood types are an example of how glycolipids on cell membranes mediate cell interactions with the surrounding environment. The four main human blood types (A, B, AB, O) are determined by the oligosaccharide attached to a specific glycolipid on the surface of red blood cells, which acts as an antigen. The unmodified antigen, called the H antigen, is the characteristic of type O, and is present on red blood cells of all blood types. Blood type A has an N-acetylgalactosamine added as the main determining structure, type B has a galactose, and type AB has all three of these antigens.
Aldose reductase is the first enzyme in the sorbitol-aldose reductase pathway responsible for the reduction of glucose to sorbitol, as well as the reduction of galactose to galactitol. Too much sorbitol trapped in retinal cells, the cells of the lens, and the Schwann cells that myelinate peripheral nerves, is a frequent result of long-term hyperglycemia that accompanies poorly controlled diabetes. This can damage these cells, leading to retinopathy, cataracts and peripheral neuropathy, respectively. Aldose reductase inhibitors, which are substances that prevent or slow the action of aldose reductase, are currently being investigated as a way to prevent or delay these complications.
The full name of B transferase is alpha 1-3-galactosyltransferase, and its function in the cell is to add a galactose molecule to H-antigen, creating B-antigen. It is possible for Homo sapiens to have any of four different blood types: Type A (express A antigens), Type B (express B antigens), Type AB (express both A and B antigens) and Type O (express neither A nor B antigens). The gene for A and B transferases is located on chromosome 9. The gene contains seven exons and six introns and the gene itself is over 18kb long.
Each agarose chain contains ~800 molecules of galactose, and the agarose polymer chains form helical fibres that aggregate into supercoiled structure with a radius of 20-30 nm. The fibers are quasi-rigid, and have a wide range of length depending on the agarose concentration. When solidified, the fibres form a three-dimensional mesh of channels of diameter ranging from 50 nm to >200 nm depending on the concentration of agarose used - higher concentrations yield lower average pore diameters. The 3-D structure is held together with hydrogen bonds and can therefore be disrupted by heating back to a liquid state.
Guillain–Barré syndrome – nerve damage Schwann cells are active in Wallerian degeneration. They not only have a role in phagocytosis of myelin, but they also have a role in recruitment of macrophages to continue the phagocytosis of myelin. The phagocytic role of Schwann cells has been investigated by studying the expression of molecules in Schwann cells that are typically specific to inflammatory macrophages. Expression of one such molecule MAC-2, a galactose-specific lectin, is observed in not only degenerating nerves that are macrophage-rich but also degenerating nerves that are macrophage-scarce and Schwann cell-rich.
In 1956, Afanasy S. Troshin published a book, The Problems of Cell Permeability, in Russian (1958 in German, 1961 in Chinese, 1966 in English) in which he found that permeability was of secondary importance in determination of the patterns of equilibrium between the cell and its environment. Troshin showed that cell water decreased in solutions of galactose or urea although these compounds did slowly permeate cells. Since the membrane theory requires an impermanent solute to sustain cell shrinkage, these experiments cast doubt on the theory. Others questioned whether the cell has enough energy to sustain the sodium/potassium pump.
In contrast, G0 glycans, which lack galactose and terminate instead with GlcNAc moieties, have increased affinity for FcγRIIIA. Another FcR is expressed on multiple cell types and is similar in structure to MHC class I. This receptor also binds IgG and is involved in preservation of this antibody. However, since this Fc receptor is also involved in transferring IgG from a mother either via the placenta to her fetus or in milk to her suckling infant, it is called the neonatal Fc receptor (FcRn). Recently, research suggested that this receptor plays a role in the homeostasis of IgG serum levels.
As type II membrane proteins, they have an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. By sequence similarity, the beta4GalTs form four groups: beta4GalT1 and beta4GalT2, beta4GalT3 and beta4GalT4, beta4GalT5 and beta4GalT6, and beta4GalT7. This gene is unique among the beta4GalT genes because it encodes an enzyme that participates both in glycoconjugate and lactose biosynthesis. For the first activity, the enzyme adds galactose to N-acetylglucosamine residues that are either monosaccharides or the nonreducing ends of glycoprotein carbohydrate chains.
PRKAB1 has been shown to interact with PRKAG2 and PRKAG1. The 5'-AMP-activated protein kinase beta subunit interaction domain (AMPKBI) is a conserved domain found in the beta subunit of the 5-AMP-activated protein kinase complex, and its yeast homologues Sip1 (SNF1-interacting protein 1), Sip2 (SNF1-interacting protein 2) and Gal83 (galactose metabolism 83), which are found in the SNF1 (sucrose non-fermenting) kinase complex. This region is sufficient for interaction of this subunit with the kinase complex, but is not solely responsible for the interaction, and the interaction partner is not known.
He is credited with conducting chemical analyses of over one thousand human and animal brains. In his research, he isolated and characterized numerous compounds of the brain, such as cephalin, sphingomyelin, galactose, lactic acid and sphingosine. In 1884 he explained his findings in a publication titled "A Treatise on the Chemical Constitution of the Brain", a book that was widely criticized and rejected at the time by many in the scientific community. After his death, Thudichum's discoveries were realized to be important scientific contributions to the study of the chemical and molecular composition of the brain.
In enzymology, a galactitol-1-phosphate 5-dehydrogenase () is an enzyme that catalyzes the chemical reaction :galactitol-1-phosphate + NAD+ \rightleftharpoons L-tagatose 6-phosphate + NADH + H+ Thus, the two substrates of this enzyme are galactitol-1-phosphate and NAD+, whereas its 3 products are L-tagatose 6-phosphate, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is galactitol-1-phosphate:NAD+ oxidoreductase. This enzyme participates in galactose metabolism. It employs one cofactor, zinc.
Hexose transporters (HXT) are a group of proteins that are largely responsible for the uptake of glucose in yeast. In S. cerevisiae, 20 HXT genes have been identified and 17 encode for glucose transporters (HXT1-HXT17), GAL2 encodes for a galactose transporter, and SNF3 and RGT2 encode for glucose sensors. The number of glucose sensor genes have remained mostly consistent through the budding yeast lineage, however glucose sensors are absent from Schizosaccharomyces pombe. Sch. pombe is a Crabtree-positive yeast, which developed aerobic fermentation independently from Saccharomyces lineage, and detects glucose via the cAMP-signaling pathway.
Pioneered by Stanley Fields and Ok-Kyu Song in 1989, the technique was originally designed to detect protein–protein interactions using the Gal4 transcriptional activator of the yeast Saccharomyces cerevisiae. The Gal4 protein activated transcription of a gene involved in galactose utilization, which formed the basis of selection. Abstract is free; full-text article is not. Since then, the same principle has been adapted to describe many alternative methods, including some that detect protein–DNA interactions or DNA-DNA interactions, as well as methods that use different host organisms such as Escherichia coli or mammalian cells instead of yeast.
Birch sap sugar is about 42–54% fructose and 45% glucose, with a small amount of sucrose and trace amounts of galactose. The main sugar in maple syrup is the more complex sucrose and the chemical contents of maple syrup is also different, leading to a flavor difference. The flavor of birch syrup has a distinctive and mineral-rich caramel-like taste that is not unlike molasses or balsamic condiment or some types of soy, with a hint of spiciness. Different types of birch will produce slightly different flavour profiles; some more copper, others with hints of wildflower honey.
They are unable to utilize D-maltose, D-trehalose, D-cellobiose, gentiobiose, sucrose, D-raffinose, α-D-glucose, D-turanose, D-melibose, mannose, galactose, 3-methyle glucose, inosine, D-aspartic acid, glycyl-L-proline, L-alanine, L-arginine, L-serine, pectine, D-saccharic acid, p-hydroxy-phenylacetic acid, methyl pyruvate, citric acid, bromo-succinic acid, acetoacetic acid or propionic acid. R. lentis can grow in the presence of the antibiotic compounds lincomycin, tetrazolium violet and tetrazolium blue but not with 1% sodium lactate, troleandomycin, lithium chloride, potassium tellurite or sodium butyrate. The type strain of R. lentis is BLR27T (= LMG 28441T = DSMZ 29286T).
The common dietary monosaccharides galactose, glucose and fructose are all reducing sugars. Disaccharides are formed from two monosaccharides and can be classified as either reducing or nonreducing. Nonreducing disaccharides like sucrose and trehalose have glycosidic bonds between their anomeric carbons and thus cannot convert to an open-chain form with an aldehyde group; they are stuck in the cyclic form. Reducing disaccharides like lactose and maltose have only one of their two anomeric carbons involved in the glycosidic bond, while the other is free and can convert to an open-chain form with an aldehyde group.
All monosaccharides are reducing sugars because they either have an aldehyde group (if they are aldoses) or can tautomerize in solution to form an aldehyde group (if they are ketoses). This includes common monosaccharides like galactose, glucose, glyceraldehyde, fructose, ribose, and xylose. Many disaccharides, like cellobiose, lactose, and maltose, also have a reducing form, as one of the two units may have an open-chain form with an aldehyde group. However, sucrose and trehalose, in which the anomeric carbons of the two units are linked together, are nonreducing disaccharides since neither of the rings is capable of opening.
Although telomerase activation does not occur during the cell cycle of normal somatic human cells, the association between telomere elongation (especially elongation by telomerase) and tumor development emphasizes the importance of understanding when such elongation can occur during the cell cycle. Work with S. cerevisiae has identified telomerase activity as restricted to late S phase. Researchers generated S. cerevisiae strains with galactose-inducible shortened telomeres. They then used α factor to block cells with induced short telomeres in late G1 phase and measured the change in telomere length when the cells were released under a variety of conditions.
It is a disaccharide formed from one molecule each of the simple sugars (monosaccharides) fructose and galactose. Lactulose is not normally present in raw milk, but is a product of heat processes: the greater the heat, the greater amount of this substance (from 3.5 mg/l in low-temperature pasteurized milk to 744 mg/l in in-container sterilized milk). It is produced commercially by isomerization of lactose. Lactulose is not absorbed in the small intestine nor broken down by human enzymes, thus stays in the digestive bolus through most of its course, causing retention of water through osmosis leading to softer, easier-to-pass stool.
Genes encoding coproporphyrinogen oxidase, an essential enzyme in the heme biosynthetic pathway were found as well as genes associated with the electron transport chain and oxidative phosphorylation. The citric acid cycle also has a role in its energy metabolism with 18% of metabolic genes relating to TCA cycle function. Saccharide metabolism associated genes were also found for the metabolism of: galactose, fructose, mannose, sucrose, starch, nucleotide sugars, amino sugars, as well as glycoprotein and peptide-protein biosynthesis. Many genes have been identified in this species that support protein biosynthesis and proteolytic systems including: glutamate, methionine and tryptophan metabolism; phenylalanine, valine, leucine and isoleucine degradation; valine, leucine, isoleucine, tyrosine and tryptophan biosynthesis.
Both animals and plants temporarily store the released energy in the form of high-energy molecules, such as ATP, for use in various cellular processes. Although humans consume a variety of carbohydrates, digestion breaks down complex carbohydrates into a few simple monomers (monosaccharides) for metabolism: glucose, fructose, and galactose. Glucose constitutes about 80% of the products and is the primary structure that is distributed to cells in the tissues, where it is broken down or stored as glycogen. In aerobic respiration, the main form of cellular respiration used by humans, glucose and oxygen are metabolized to release energy, with carbon dioxide and water as byproducts.
Locust bean gum occurs as a white to yellow-white powder. It consists chiefly of high-molecular-weight hydrocolloidal polysaccharides, composed of galactose and mannose units combined through glycosidic linkages, which may be described chemically as galactomannan. It is dispersible in either hot or cold water, forming a sol having a pH between 5.4 and 7.0, which may be converted to a gel by the addition of small amounts of sodium borate. Locust bean gum is composed of a straight backbone chain of D-mannopyranose units with a side-branching unit of D-galactopyranose having an average of one D-galactopyranose unit branch on every fourth D-mannopyranose unit.
An example is D-galactose—it has four chiral centers, but D-galactaric and L-galactaric acids, which have the opposite configuration at each chiral center and therefore would be expected to be enantiomers, are actually the same compound; therefore, galactaric acid is an achiral meso form with no optical activity. Again, this can be understood by taking the Fischer projection of either acid and looking at it upside down—the configuration is now switched at every carbon. File:Aldaric_acids.gif Adipic acid, HOOC-(CH2)4-COOH, is not an aldaric acid, though it is structurally similar. In fact, six-carbon aldaric acids can be considered tetrahydroxyl derivatives of adipic acid.
E. histolytica has a lectin that binds to galactose and N-acetylgalactosamine sugars on the surface of the epithelial cells, The lectin normally is used to bind bacteria for ingestion. The parasite has several enzymes such as pore forming proteins, lipases, and cysteine proteases, which are normally used to digest bacteria in food vacuoles but which can cause lysis of the epithelial cells by inducing cellular necrosis and apoptosis when the trophozoite comes in contact with them and binds via the lectin. Enzymes released allow penetration into intestinal wall and blood vessels, sometimes on to liver and other organs. The trophozoites will then ingest these dead cells.
Second generation biofuels use lignocellulosic raw material such as forest residues (sometimes referred to as brown waste and black liquor from Kraft process or sulfite process pulp mills). Third generation biofuels (biofuel from algae) use non-edible raw materials sources that can be used for biodiesel and bioethanol. It has long been recognized that the huge supply of agricultural cellulose, the lignocellulosic material commonly referred to as "Nature's polymer", would be an ideal source of material for biofuels and many other products. Composed of lignin and monomer sugars such as glucose, fructose, arabinose, galactose, and xylose, these constituents are very valuable in their own right.
The sequence identified overlapped a binding site for GAL4 protein, which is a positive regulator for transcription which coincides with the function of upstream activating sequences. Another study looked at the effect of inserting the UAS into the promoter region of the glyceraldehyde-3-phosphate dehydrogenase gene (GPD) . This hybrid promoter was then utilized to express human immune interferon, a toxic substance to yeast that results in a reduced copy number and low plasmid stability. Relative to the native promoter, expression of the hybrid promoter was induced roughly 150- to 200-fold in the cultures by growth in galactose, induction that wasn't apparent with glucose as the carbon source.
A reducing end of a carbohydrate is a carbon atom that can be in equilibrium with the open-chain aldehyde (aldose) or keto form (ketose). If the joining of monomers takes place at such a carbon atom, the free hydroxy group of the pyranose or furanose form is exchanged with an OH-side-chain of another sugar, yielding a full acetal. This prevents opening of the chain to the aldehyde or keto form and renders the modified residue non-reducing. Lactose contains a reducing end at its glucose moiety, whereas the galactose moiety forms a full acetal with the C4-OH group of glucose.
Several variants have been specifically formulated and prepared for use on pizza, such as low-moisture Mozzarella cheese. The International Dictionary of Food and Cooking defines this cheese as "a soft spun-curd cheese similar to Mozzarella made from cow's milk" that is "[u]sed particularly for pizzas and [that] contains somewhat less water than real Mozzarella". Low-moisture part-skim mozzarella, widely used in the food-service industry, has a low galactose content, per some consumers' preference for cheese on pizza to have low or moderate browning.Galactose is a type of sugar found in dairy products and other foods that is less sweet than glucose.
The conjugation was confirmed by liquid chromatography- electrospray ionisation-mass spectrometry (LC-ESI-MS) and lectin blot with the GlcNAc-binding wheat germ agglutinin attached to AlexaFluor 647. Having successfully introduced GlcNAc, the monomer was extended with a glycan structure containing GlcNAc, mannose (Man) and galactose (Gal) (Fig. 3C). A mutant endoglycosidase EndoS (EndoS-D233Q) was utilised as it is highly specific for IgG Fc N-linked GlcNAc residues and does not elongate Asn-GlcNAc sites on other proteins or on denatured IgGs. Product formation was again monitored by LC-ESI-MS and lectin blot probing with the sialic acid-binding sambucus nigra agglutinin attached to fluorescein isothiocyanate.
Like first-generation Glycoazodyes, second-generation Glycoazodyes are synthesized using a glucose, galactose, or lactose sugar group. The point of the ether bond is controlled by selectively protecting alcohol groups on the sugar, or by choosing an azo dye with a different alcohol group position. An unprotected alcohol group of either the sugar or the dye is reacted with an n-carbon, terminal dibromoalkane in a solution of potassium hydroxide and 18-crown-6 ether, using non-anhydrous tetrahydrofuran as the solvent. The potassium hydroxide is used to produce an alkoxide ion from the alcohol while the 18-crown-6 ether acts as a phase-transfer agent.
At the University of Michigan, Ann Arbor, Bhaduri was associated with Paul Srere and worked on citrate metabolism and fatty acid biosynthesis. It was during his post-doctoral studies at Harvard Medical School, he elucidated the effect of uridine nucleotides on an epimerase. Later, he continued his researches at Jadavpur University and discovered methodologies for the purification of Glucose-6-phosphate dehydrogenase and for the regulation of UDP-glucose 4-epimerase from S. fragilis. His researches revealed that the enzyme was allosterically activated by metabolically-related sugar phosphates and its allosteric kinetics is uni- directional, a property helpful in the regulation of galactose metabolism.
Xyloglucan backbone synthesis is mediated by cellulose synthase-like protein family C (CSLC), particularly glucan synthase, which adds glucose units to the chain. Backbone synthesis of xyloglucan is also mediated in some way by xylosyltransferase, but this mechanism is separate to its transferase function and remains unclear. Xylosyltransferase in its transferase function is, however, utilized for the addition of xylose to the side-chain. Other enzymes utilized for side- chain synthesis of xyloglucan include galactosyltransferase (which is responsible for the addition of galactose and of which two different forms are utilized), fucosyltransferase (which is responsible for the addition of fucose), and acetyltransferase (which is responsible for acetylation).
HS synthesis initiates with the transfer of xylose from UDP- xylose by xylosyltransferase (XT) to specific serine residues within the protein core. Attachment of two galactose (Gal) residues by galactosyltransferases I and II (GalTI and GalTII) and glucuronic acid (GlcA) by glucuronosyltransferase I (GlcATI) completes the formation of a core protein linkage tetrasaccharide βGlcA-1,3-βGal-1,3-βGal-1,4-βXyl. Xylose attachment to the core protein is thought to occur in the endoplasmic reticulum (ER) with further assembly of the linkage region and the remainder of the chain occurring in the golgi apparatus. The pathways for HS/heparin or chondroitin sulfate (CS) and dermatan sulfate (DS) biosynthesis diverge after the formation of this common linkage structure.
If the family of the baby has a history of galactosemia, doctors can test prior to birth by taking a sample of fluid from around the fetus (amniocentesis) or from the placenta (chorionic villus sampling or CVS). Galactosemia is normally first detected through newborn screening which if available, is able to diagnose the majority of affected infants. A galactosemia test is a blood test (from the heel of the infant) or urine test that checks for three enzymes that are needed to change galactose sugar that is found in milk and milk products into glucose, a sugar that the human body uses for energy. A person with galactosemia doesn't have one of these enzymes.
Open-chain form as an intermediate product between α and β anomer Open-chain form of D-galactose Though the cyclic forms of sugars are usually heavily favoured, hemiacetals in aqueous solution are in equilibrium with their open-chain forms. In aldohexoses this equilibrium is established as the hemiacetal bond between C-1 (the carbon bound to two oxygens) and C-5 oxygen is cleaved (forming the open- chain compound) and reformed (forming the cyclic compound). When the hemiacetal group is reformed, the OH group on C-5 may attack either of the two stereochemically distinct sides of the aldehyde group on C-1. Which side it attacks on determines whether the α- or β-anomer is formed.
It does not increase in concentration until the rate of lactate production exceeds the rate of lactate removal, which is governed by a number of factors, including monocarboxylate transporters, concentration and isoform of LDH, and oxidative capacity of tissues. The concentration of blood lactate is usually at rest, but can rise to over 20 mM during intense exertion and as high as 25 mM afterward. In addition to other biological roles, -lactic acid is the primary endogenous agonist of hydroxycarboxylic acid receptor 1 (HCA1), which is a G protein- coupled receptor (GPCR). In industry, lactic acid fermentation is performed by lactic acid bacteria, which convert simple carbohydrates such as glucose, sucrose, or galactose to lactic acid.
There are also other rare conditions, such as portosystemic venous shunting and hepatic arteriovenous malformations, or Fanconi-Bickel Syndrome (GSDXI) that can lead to elevated blood galactose or urinary galactitol, potentially triggering an initial suspicion of galactosemia.Nishimura Y, Tajima G, Dwi Bahagia A, Sakamoto A, Ono H, Sakura N, Naito K, Hamakawa M, Yoshii C, Kubota M, Kobayashi K, Saheki T. Differential diagnosis of neonatal mild hypergalactosaemia detected by mass screening: clinical significance of portal vein imaging. J Inherit Metab Dis. 2004;27(1):11-8. If the NBS result is based only on GALT activity and not on metabolite levels then the differential diagnosis would include classic galactosemia, clinical variant galactosemia, DG, and false positive.
Jacalin is a plant-based lectin, but not a legume lectin, found in jackfruit. It has been studied for capturing O-glycoproteins such as mucins and IgA1, for potential applications in human immunology.Glycobiology:Elucidation of binding specificity of Jacalin toward O-glycosylated peptides: quantitative analysis by frontal affinity chromatography Jacalin belongs to a family of galactose- binding lectins containing the Jacalin-like lectin domain and it has a tetrameric two-chain structure with a weight of 66 kDa Jacalin is preferably used in applications to isolate IgA from human serum, isolating human plasma glycoproteins and for applications in histochemistry. The lectin is blood group non-specific after neuraminidase treatment and agglutinates human erythrocytes at a concentration of ≥ 7,8 µg/ml.
The chemical formula of Lactosylceramide is C42H79NO13, which has 806.088 g/mol of molar mass. Moreover, The IUPAC name of LacCer is N-(dodecanoyl)-1-beta- lactosyl-sphing-4-enine . Lactosylceramides were initially called 'cytolipin H'. It is found in small amounts just in most creature tissues, however, it has various huge organic capacities and it is of extraordinary significance as the biosynthetic forerunner of the greater part of the impartial oligoglycosylceramides, sulfatides and gangliosides. In creature tissues, biosynthesis of lactosylceramide includes expansion of the second monosaccharides unit (galactose) as its nucleotide subsidiary to monoglucosylceramide, catalyzed by a particular beta-1, 4-galactosyltransferase on the lumenal side of the Golgi mechanical assembly.
The presence of presenile cataract, noticeable in galactosemic infants as young as a few days old, is highly associated with two distinct types of galactosemia: GALT deficiency and to a greater extent, GALK deficiency. An impairment or deficiency in the enzyme, galactose-1-phosphate uridyltransferase (GALT), results in classic galactosemia, or Type I galactosemia. Classic galactosemia is a rare (1 in 47,000 live births), autosomal recessive disease that presents with symptoms soon after birth when a baby begins lactose ingestion. Symptoms include life-threatening illnesses such as jaundice, hepatosplenomegaly (enlarged spleen and liver), hypoglycemia, renal tubular dysfunction, muscle hypotonia (decreased tone and muscle strength), sepsis (presence of harmful bacteria and their toxins in tissues), and cataract among others.
A similar mechanism has been claimed to underlie Henoch–Schönlein purpura, a vasculitis that mainly affects children and can feature renal involvement that is almost indistinguishable from IgA nephritis. However, human studies have found that degalactosylation of IgA1 occurs in patients with IgA nephropathy in response only to gut antigen exposures (not systemic), and occurs in healthy people to a lesser extent. This strongly suggests degalactosylation of IgA1 is a result of an underlying phenomenon (abnormal mucosal antigen handling) and not the ultimate cause of IgA nephropathy. Prevailing evidence suggests that both galactose-deficient o-glycans in the hinge region of IgA1 and synthesis and binding of antibodies against IgA1 are required for immunoglobulin complexes to form and accumulate in glomeruli.
It is possible that food and environmental antigens (bacterial, viral, or plant antigens) have epitopes similar enough to A and B glycoprotein antigens. The antibodies created against these environmental antigens in the first years of life can cross-react with ABO-incompatible red blood cells that it comes in contact with during blood transfusion later in life. Anti-A antibodies are hypothesized to originate from immune response towards influenza virus, whose epitopes are similar enough to the α-D-N- galactosamine on the A glycoprotein to be able to elicit a cross-reaction. Anti-B antibodies are hypothesized to originate from antibodies produced against Gram-negative bacteria, such as E. coli, cross-reacting with the α-D- galactose on the B glycoprotein.
In organic chemistry, the Le Bel–Van 't Hoff rule states that the number of stereoisomers of an organic compound containing no internal planes of symmetry is 2n, where n represents the number of asymmetric carbon atoms. Joseph Achille Le Bel and Jacobus Henricus van 't Hoff both announced this hypothesis in 1874 and that this accounted for all molecular asymmetry known at the time. As an example, four of the carbon atoms of the aldohexose class of molecules are asymmetric, therefore the Le Bel–Van 't Hoff rule gives a calculation of 24 = 16 stereoisomers. This is indeed the case: these chemicals are two enantiomers each of eight different diastereomers: allose, altrose, glucose, mannose, gulose, idose, galactose, and talose.
Under aerobic conditions, for example, D-glucose is used, but no acid is formed, as would be typical for fermentation. Other usable substrates are glycerol, L-arabinose, D-xylose, D-galactose, D-glucose, D-fructose, D-mannose, L-rhamnose, D-mannitol, N-acetylglucosamine, arbutin, aesculin, salicin, D-cellobiose, D-maltose, D-melibiose, sucrose, D-trehalose, D-raffinose, starch, glycogen, D-turanose, potassium gluconate and potassium 5-ketogluconate. Furthermore amino acids leucine and valine are assimilated. Carbohydrates that cannot be used are erythritol, D-arabinose, D-ribose, L-xylose, D-ribitol, methyl-β-D-xylopyranoside, L-sorbose, dulcitol, inositol, D-sorbitol, Methly-α-D-mannopyranoside, methly-α-D-glucopyranoside, amygdalin, D-lactose, inulin, D-melezitose, xylitol, gentiobiose, D-lyxose, D-tagatose, fucose, arabitol and potassium 2-ketogluconate.
For example, all states in the US screen for classic galactosemia in their NBS panel, but some states have lower GALT enzyme activity cut-off levels than others. NBS in states with a low GALT cut off level still detect classic galactosemia, but are likely to miss many infants with DG. In those states, a normal NBS result for galactosemia may not be informative about an infant's DG status. Most infants with DG who are flagged by a positive NBS result for galactosemia have their diagnosis confirmed in a follow-up evaluation. The differential diagnosis for a positive newborn screening result for galactosemia, especially if based on galactose metabolite levels, includes: classic galactosemia, clinical variant galactosemia, DG, GALE (epimerase) deficiency, GALK (galactokinase) deficiency, or a false positive result.
The second control mechanism is a response to glucose, which uses the catabolite activator protein (CAP) homodimer to greatly increase production of β-galactosidase in the absence of glucose. Cyclic adenosine monophosphate (cAMP) is a signal molecule whose prevalence is inversely proportional to that of glucose. It binds to the CAP, which in turn allows the CAP to bind to the CAP binding site (a 16 bp DNA sequence upstream of the promoter on the left in the diagram below, about 60 bp upstream of the transcription start site), which assists the RNAP in binding to the DNA. In the absence of glucose, the cAMP concentration is high and binding of CAP-cAMP to the DNA significantly increases the production of β-galactosidase, enabling the cell to hydrolyse lactose and release galactose and glucose.
The addition of O-fucose by POFUT1 is absolutely necessary for notch function, and, without the enzyme to add O-fucose, all notch proteins fail to function properly. As yet, the manner by which the glycosylation of notch affects function is not completely understood. The O-glucose on notch can be further elongated to a trisaccharide with the addition of two xylose sugars by xylosyltransferases, and the O-fucose can be elongated to a tetrasaccharide by the ordered addition of an N-acetylglucosamine (GlcNAc) sugar by an N-Acetylglucosaminyltransferase called Fringe, the addition of a galactose by a galactosyltransferase, and the addition of a sialic acid by a sialyltransferase. To add another level of complexity, in mammals there are three Fringe GlcNAc-transferases, named lunatic fringe, manic fringe, and radical fringe.
While α-galactose as a part of glycoprotein glycans from vertebrates other than higher apes was known for a long time as being a prominent xeno-antigen, its implication in allergy only began to materialize when complications during treatment with a recombinant monoclonal antibody (Erbitux) were attributed to IgE directed against α-Gal containing N-glycans on this antibody. The incidencies of anaphylaxis due to Erbitux were confined to a certain area in the eastern United States, which raised speculations about the involvement of a particular type of tick endemic in this area. However, IgE antibodies against the α-Gal epitope should be taken into account in the diagnosis of milk and meat allergy. It is currently largely unexplored whether this type of CCD is generally also clinically irrelevant such as the plant/insect CCDs.
The formation of a disaccharide molecule from two monosaccharide molecules proceeds by displacing a hydroxyl radical from one molecule and a hydrogen nucleus (a proton) from the other, so that the now vacant bonds on the monosaccharides join the two monomers together. The vacant bonds on the hydroxyl radical and the proton unite in their turn, forming a molecule of water, that then goes free. Because of the removal of the water molecule from the product, the term of convenience for such a process is "dehydration reaction" (also "condensation reaction" or "dehydration synthesis"). For example, milk sugar (lactose) is a disaccharide made by condensation of one molecule of each of the monosaccharides glucose and galactose, whereas the disaccharide sucrose in sugar cane and sugar beet, is a condensation product of glucose and fructose.
Mature brown to yellow coffee beans contain fewer residues of galactose and arabinose at the side chain of the polysaccharides, making the green coffee bean more resistant to physical breakdown and less soluble in water. The molecular weight of the arabinogalactan in coffee is higher than in most other plants, improving the cellular defense system of the digestive tract compared to arabinogalactan with lower molecular weight.Gotoda, N and Iwai, K. (2006) "Arabinogalactan isolated from coffee seeds indicates immunomodulating properties", pp. 116–120 in Association for Science and Information on Coffee, (ASIC) 21st International Conference on Coffee Science, 11 – 15 September 2006, Montpellier, France Free monosaccharides are present in mature brown to yellow-green coffee beans. The free part of monosaccharides contains sucrose (gluco-fructose) up to 9000 mg/100g of arabica green coffee bean, a lower amount in robustas, i.e.
In creature tissues, the antecedent glucosylceramide is moved by the sphingolipid transport protein FAPP2 to the distal Golgi, where it should initially cross from the cytosolic side of the membrane conceivably by means of the activity of a flippase. Biosynthesis of lactosylceramide then includes expansion of the second monosaccharides unit as its actuated nucleotide subordinate (UDP-galactose) to monoglucosylceramide on the lumenal side of the Golgi apparatus in a response catalyzed by β-1,4-galactosyltransferases of which two are known. The lactosylceramide created can be further glycosylated, or it very well may be moved to the plasma layer essentially by a non- vesicular system that is inadequately seen, however it can't be translocated back to the cytosolic flyer. It is likewise recovered by the catabolism of a considerable lot of the lipids for which it is the biosynthetic antecedent.
For example, a glucose polymer is named glucan, a mannose polymer is named mannan, and a galactose polymer is named galactan. When the glycosidic linkages and configurations of the monosaccharides are known, they may be included as a prefix to the name, with the notation for glycosidic linkages preceding the symbols designating the configuration. The following example will help illustrate this concept: (1→4)-β-D-Glucan (1→4)-β-D-Glucan A heteropolysaccharide is a polymer containing more than one kind of monosaccharide residue. The parent chain contains only one type of monosaccharide and should be listed last with the ending “-an”, and the other types of monosaccharides listed in alphabetical order as “glyco-” prefixes. When there is no parent chain, all different monosaccharide residues are to be listed alphabetically as “glyco-” prefixes and the name should end with “-glycan”.
The AGs are O-glycosidically linked to clustered non-contiguous Hyp residues on the protein backbone (Hyp contiguity hypothesis). On some AGPs, single galactose (Gal) residues may also be found to be O-glycosidically attached to Ser/Thr, for example, in green algae. The carbohydrate moieties of AGPs are rich in arabinose and galactan, but other sugars may also be found such as L-rhamnopyranose (L-Rhap), D-mannopyranose (Manp), D-xylopyranose (Xylp), L-fucose (Fuc), D-glucopyranose (Glcp), D-glucuronic acid (GlcA) and its 4-O-methyl derivative, and D-galacturonic acid (GalA) and its 4-O-methyl derivative. The AG found in AGPs is of type II (type II AGs) – that is, a galactan backbone of (1-3)-linked β-D-galactopyranose (Galp) residues, with branches (between one and three residues long) of (1,6)-linked β-D-Galp.
This species secretes amylase at the end of its exponential phase, and it is believed to produce the most amylase at 30 °C between pH 4.5 and pH 6. It is believed that the amylases that are produced by C. aerius are able to digest raw starch, and this ability to break down raw starch has been studied extensively, because the ability to find microorganisms that can break down raw starch has become increasingly important as the production of materials such as liquid fuel and chemicals using starch has become more prominent. This species ability to break down starch is greatly improved when it is cocultured with Saccharomyces cerevisiae. C. aerius is able to use glucose, galactose, maltose and starch as sole carbon sources, and it is able to use nitrate and nitrite as sole nitrogen sources.
Studies observing unrestricted sugar intake of females correlated sucrose intake level with maximum accumulation of stored energy reserves. In contrast, sucrose intake level does not correlate with decreased activity or changes in senescence. Carbohydrate feedings of female mosquitoes in a laboratory setting indicated that carbohydrates glucose, fructose, mannose, galactose, sucrose, trehalose, melibiose, maltose, raffinose, melizitose, dextrin, mannitol, and sorbitol are most effective to aid survival; arabinose, rhamnose, fucose, sorbose, lactose, cellobiose, inulin, a-methyl mannoside, dulcitol, and inositol are not used by the species; xylose, glycogen, a-methyl glucoside, and glycerol are used but at a slow metabolic rate; and sorbose could not be metabolized. Feeding with glucose allowed for maximum flight speed while other carbohydrates, such as all pentoses, sorbose, lactose, cellobiose, glycogen, inulin, a-methyl mannoside, dulcitol, and inositol were insufficient to allow flight, indicated by a delay in flight after feeding.
His research is on the field of metabolic regulation, including its effect of human metabolic defects. His most cited article is Kent Lai, D, S.D. Langley, R.H. Singh, P.P. Dembure, L.N. Hjelm, L.J. Elsas II "A prevalent mutation for galactosemia among black Americans" Journal of Pediatrics January 1996Volume 128, Issue 1, Pages 89–95, which, according to Google Scholar, has received 86 citations. Another paper,Kent Lai, Cynthia P. Bolognese, Steve Swift and Patricia McGraw( "Regulation of Inositol Transport in Saccharomyces cerevisiae Involves Inositol-induced Changes in Permease Stability and Endocytic Degradation in the Vacuole" Journal of Biological Chemistry (1995), 270, 2525-2534, has received 70 citations. A third, K Lai, LJ Elsas "Overexpression of human UDP-glucose pyrophosphorylase rescues galactose-1-phosphate uridyltransferase-deficient yeast" Biochemical and Biophysical Research Communications Volume 271, Issue 2, 10 May 2000, Pages 392–400 has 61 citations Google Scholar Accessed Aug 13, 2015.
Fungal growth is affected by the presence of optimal nutrients necessary for growth, by the presence of minerals, by temperature, by pH and by osmotic pressure. The presence of organic nutrients in the medium that C. coronatus finds itself in favors the formation of vegetative germ tubes, with glucose inducing vegetative germ growth far more effectively than asparagine. In terms of necessary nutrients for growth and survival, glucose and trehalose are both good sources of carbon for C. coronatus, other adequate sources of carbon are fructose, mannose, maltose, glycerol, oleate, stearate, palmitate and casamino acids, whereas galactose, starch and glycogen are all poor sources of carbon for C. coronatus. When looking at nitrogen, complex nitrogen sources seem to be best suited for optimal C. coronatus growth, however L-asparagine, ammonium salts, L-aspartic acid, glycine, L-alanine, L-serine, N-acetyl-D-glucosamine and urea can all adequately be used by the fungus as nitrogen sources to varying extents.
Letters from Daisy Dussoix in 1978 where she expresses her frustration about the lack of recognition of her research which led Werner Arber to obtain the Nobel prize Arber studied chemistry and physics at the Swiss Federal Institute of Technology in Zürich from 1949 to 1953. Late in 1953, he took an assistantship for electron microscopy at the University of Geneva, in time left the electron microscope, went on to research bacteriophages and write his dissertation on defective lambda prophage mutants. In his Nobel Autobiography, he writes: > In the summer of 1956, we learned about experiments made by Larry Morse and > Esther and Joshua Lederberg on the lambda-mediated transduction (gene > transfer from one bacterial strain to another by a bacteriophage serving as > vector) of bacterial determinants for galactose fermentation. Since these > investigators had encountered defective lysogenic strains among their > transductants, we felt that such strains should be included in the > collection of lambda prophage mutants under study in our laboratory.
They are very sensitive to ampicillin and resistant to kanamycin and nalidixic acid. Strains do not tolerate tetracycline and do not grow on LB medium. R. binae can utilize a variety of nutrients, including dextrin, D-maltose, D-trehalose, D-cellobiose, gentiobiose, sucrose, D-raffinose, α-D- glucose, D-turanose, α-D lactose, D-fructose, D-melibiose, β-methyl-D- glucoside, salicin, N-acetyl-D-galactosamine, D-mannose, D-galactose, D-mannitol, D-sorrbitol, D-arabitol, glycerol, D-glucose-6-phosphate, D-fructose-6-phosphate, D-alanine, L-aspartic acid, L-histidine, l-pyroglutamic acid, quinic acid, D-saccharic acid, methyl pyruvate, L-lactic acid, citric acid, D-malic acid, L-malic acid, bromo-succinic acid, β-hydroxy-d,l-butyric acid and acetic acid. R. binae can not use the nutrients N-acetyle-D-mannosamine, 3-methyle glucose, inosine, glycyl-L-proline, L-arginine, D-galacturonic acid, D-glucuronic acid, glucuronamide, p-hydroxy- phenylacetic acid, D-lactic acid methyl ester, α-keto-glutaric acid, tween 40, propionic acid or formic acid.

No results under this filter, show 584 sentences.

Copyright © 2024 RandomSentenceGen.com All rights reserved.