Reaction: CMP-N-acetyl-β-neuraminate + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R
Other name(s): cytidine monophosphoacetylneuraminate-β-galactosyl(1→4)acetylglucosaminide α2→3-sialyltransferase; α2→3 sialyltransferase (ambiguous); SiaT (ambiguous); CMP-N-acetylneuraminate:β-D-galactosyl-1,4-N-acetyl-D-glucosaminyl-glycoprotein α-2,3-N-acetylneuraminyltransferase; neolactotetraosylceramide α-2,3-sialyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-glycoprotein α-(2→3)-N-acetylneuraminyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R (2→3)-N-acetyl-α-neuraminyltransferase (configuration-inverting)
Comments: The enzyme recognizes the sequence β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl (known as type 2 histo-blood group precursor disaccharide) in non-reducing termini of glycan moieties in glycoproteins and glycolipids. The enzyme from chicken brain was shown to act on neolactotetraosylceramide, producing ganglioside LM1 [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Van den Eijnden, D.H. and Schiphorst, W.E.C.M. Detection of β-galactosyl(1→4)N-acetylglucosaminide α(2→3)-sialyltransferase activity in fetal calf liver and other tissues. J. Biol. Chem. 256 (1981) 3159-3162. [PMID: 7204397]
2. Basu, M., Basu, S., Stoffyn, A. and Stoffyn, P. Biosynthesis in vitro of sialyl(α2-3)neolactotetraosylceramide by a sialyltransferase from embryonic chicken brain. J. Biol. Chem. 257 (1982) 12765-12769. [PMID: 7130178]