Alpha-1,4-N- is an enzyme that in humans is encoded by the A4GNT gene. This enzyme is part of the production of type III mucin, which is found in the stomach, duodenum, and pancreatic ducts.
Enzyme activity This enzyme functions as an , which means it moves an acetylglucosamine (GlcNAc) from one molecule to another. In this case it moves the GlcNAc from a UDP-N-acetyl-alpha-D-glucosamine donor to a galactose residue on an O-glycans. It catalyzes the following reaction:
a beta-D-galactoside + UDP-N-acetyl-alpha-D-glucosamine → an N-acetyl-alpha-D-glucosaminyl-(1->4)-beta-D-galactosyl derivative + UDP + H+
It can also apply to beta-(1->3)-linked residues.
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