b1,3-GalNAc transferase (LgtD)

b1,3-GalNAc transferase (LgtD) Accepted Name Globotriaosylceramide 3-beta-N-acetylgalactosaminyltransferase. Alternative Name(s) Beta-3GalNAc-T1. Galactosylgalactosylglucosylceramide beta-D- acetylgalactosaminyltransferase. Globoside synthase. Globoside synthetase. Uridine diphosphoacetylgalactosamine-galactosylgalactosylglucosylceramide acetylgalactosaminyltransferase. Reaction catalysed UDP-N-acetyl-alpha-D-galactosamine  +  alpha-D-galactosyl-(1->4)-beta-D-galactosyl-(1->4)-beta-D-glucosyl-(1<->1)-ceramide  <=>  UDP  +  N-acetyl-beta-D-galactosaminyl-(1->3)-alpha-D-galactosyl-(1->4)-beta-D-galactosyl-(1->4)-beta-D-glucosyl-(1<->1)-ceramide Cofactor(s) Mn(2+). Comment(s) Globoside is a neutral glycosphingolipid in human erythrocytes and has blood-group-P-antigen activity. 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. Lactosylceramide, globoside and gangliosides GM3 and GD3 are not substrates.