glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity
UDP-N-acetyl-D-glucosamine:beta-D-glucuronosyl-(1->4)-N-acetyl-alpha-D-glucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity