IUBMB Enzyme Nomenclature

EC 2.4.1.79

Accepted name: globotriaosylceramide 3-β-N-acetylgalactosaminyltransferase

Reaction: UDP-N-acetyl-α-D-galactosamine + α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide

For diagram of reaction click here.

Glossary: globotriaosylceramide = Pk antigen = α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosylceramide
globotetraosylceramide = globoside = P antigen = β-N-acetyl-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosylceramide

Other name(s): uridine diphosphoacetylgalactosamine-galactosylgalactosylglucosylceramide acetylgalactosaminyltransferase; globoside synthetase; UDP-N-acetylgalactosamine:globotriaosylceramide β-3-N-acetylgalactosaminyltransferase; galactosylgalactosylglucosylceramide β-D-acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine:globotriaosylceramide β1,3-N-acetylgalactosaminyltransferase; globoside synthase; galactosylgalactosylglucosylceramide β-D-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:D-galactosyl-1,4-D-galactosyl-1,4-D-glucosylceramide β-N-acetyl-D-galactosaminyltransferase; β3GalNAc-T1; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosylceramide 3III-β-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3III-β-N-acetyl-D-galactosaminyltransferase

Systematic name: UDP-N-acetyl-α-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide III3-β-N-acetyl-D-galactosaminyltransferase

Comments: Globoside is a neutral glycosphingolipid in human erythrocytes and has blood-group-P-antigen activity [4]. The enzyme requires a divalent cation for activity, with Mn2+ required for maximal activity [3]. UDP-GalNAc is the only sugar donor that is used efficiently by the enzyme: UDP-Gal and UDP-GlcNAc result in very low enzyme activity [3]. Lactosylceramide, globoside and gangliosides GM3 and GD3 are not substrates [4]. For explanation of the superscripted '3' in the systematic name, see GL-5.3.4.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 62213-46-1

References:

1. Chien, J.-L., Williams, T. and Basu, S. Biosynthesis of a globoside-type glycosphingolipid by a β-N-acetylgalactosaminyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1778-1785. [PMID: 4632917]

2. Ishibashi, T., Kijimoto, S. and Makita, A. Biosynthesis of globoside and Forssman hapten from trihexosylceramide and properties of β-N-acetyl-galactosaminyltransferase of guinea pig kidney. Biochim. Biophys. Acta 337 (1974) 92-106. [PMID: 4433547]

3. Taniguchi, N. and Makita, A. Purification and characterization of UDP-N-acetylgalactosamine: globotriaosylceramide β-3-N-acetylgalactosaminyltransferase, a synthase of human blood group P antigen, from canine spleen. J. Biol. Chem. 259 (1984) 5637-5642. [PMID: 6425294]

4. Okajima, T., Nakamura, Y., Uchikawa, M., Haslam, D.B., Numata, S.I., Furukawa, K., Urano, T. and Furukawa, K. Expression cloning of human globoside synthase cDNAs. Identification of β3Gal-T3 as UDP-N-acetylgalactosamine:globotriaosylceramide β1,3-N-acetylgalactosaminyltransferase. J. Biol. Chem. 275 (2000) 40498-40503. [PMID: 10993897]

[EC 2.4.1.79 created 1976, (EC 2.4.1.154 incorporated 2006), modified 2006]


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