label: galactosylgalactosylglucosylceramide beta-D-acetylgalactosaminyltransferase activity
label_lc: galactosylgalactosylglucosylceramide beta-d-acetylgalactosaminyltransferase activity
description: "Catalysis of the reaction: UDP-N-acetyl-D-galactosamine + alpha-D-galactosyl-(1->4)-beta-D-galactosyl-(1->4)-beta-D-glucosylceramide = UDP + beta-N-acetyl-D-galactosaminyl-(1->3)-alpha-D-galactosyl-(1->4)-beta-D-galactosyl-(1->4)-beta-D-glucosylceramide."