beta-D-galactosyl-(1->3)-N-acetyl-D-galactosamine + L-seryl-[protein] => a 3-O-[beta-D-galactosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl]-L-seryl-[protein] + H2O
beta-d-galactosyl-(1->3)-n-acetyl-d-galactosamine + l-seryl-[protein] => a 3-o-[beta-d-galactosyl-(1->3)-n-acetyl-alpha-d-galactosaminyl]-l-seryl-[protein] + h2o