Reaction catalyzed by glucuronosyl-N-acetylgalactosaminyl-proteoglycan 4-beta-N-acetylgalactosaminyltransferase (2.4.1.175)

		+			=			+
	UDP-N-acetyl-alpha-D-glucosamine	+		chondroitin sulfate oligosaccharide	=		UDP	+		N-acetyl-beta-D-glucosaminyl chondroitin sulfate oligosaccharide