IUBMB Enzyme Nomenclature

EC 2.4.99.2

Accepted name: β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase

Reaction: CMP-N-acetyl-β-neuraminate + a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R = CMP + an N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R

For diagram of reaction click here.

Glossary: a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[N-acetyl-α-neuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GM1a
an N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[N-acetyl-α-neuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GD1a

Other name(s): CMP-N-acetylneuraminate:D-galactosyl-N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosyl-(1↔1)-ceramide N-acetylneuraminyltransferase (ambiguous); monosialoganglioside sialyltransferase; CMP-N-acetylneuraminate:a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide N-acetyl-β-neuraminyltransferase

Systematic name: CMP-N-acetyl-β-neuraminate:a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R α-(2→3)-N-acetylneuraminyltransferase (configuration-inverting)

Comments: The enzyme recognizes the sequence β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl (known as type 1 histo-blood group precursor disaccharide) in non-reducing termini of glycan moieties in glycoproteins and glycolipids [1]. When acting on gangloside GM1a, it forms gangloside GD1a [2].

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 60202-12-2

References:

1. Rearick, J.I., Sadler, J.E., Paulson, J.C. and Hill, R.L. Enzymatic characterization of β D-galactoside α2→3 sialyltransferase from porcine submaxillary gland. J. Biol. Chem. 254 (1979) 4444-4451. [PMID: 438198]

2. Yip, M.C.M. The enzymic synthesis of disialoganglioside: rat brain cytidine-5'-monophospho-N-acetylneuraminic acid: monosialoganglioside (GM1) sialyltransferase. Biochim. Biophys. Acta 306 (1973) 298-306. [PMID: 4351506]

[EC 2.4.99.2 created 1976, modified 1986, modified 2017]


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