label: 3-O-[N-acetyl-alpha-D-glucosaminyl]-L-seryl-[protein] + UDP-N-acetyl-alpha-D-glucosamine = 3-O-[N-acetyl-beta-D-glucosaminyl-(1->6)-N-acetyl-alpha-D-glucosaminyl]-L-seryl-[protein] + UDP + H(+)
label_lc: 3-o-[n-acetyl-alpha-d-glucosaminyl]-l-seryl-[protein] + udp-n-acetyl-alpha-d-glucosamine = 3-o-[n-acetyl-beta-d-glucosaminyl-(1->6)-n-acetyl-alpha-d-glucosaminyl]-l-seryl-[protein] + udp + h(+)