preferred_name: 3-O-{beta-D-galactosyl-(1->3)-[beta-D-galactosyl-(1->4)-6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] + UDP + H(+) => 3-O-{beta-D-galactosyl-(1->3)-[6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] + UDP-alpha-D-galactose