The carbohydrate-protein binding region in keratan sulfate from bovine cornea structure of a major binding region oligosaccharide

Abstract

Peptido-keratan sulfate from bovine cornea was degraded by a combination of desulfation, hydrazinolysis, nitrous acid deamination and NaB 3H 4 reduction. The tetrasaccharide fraction obtained by gel filtration was studied by degradation with specific exoglycosidases and methylation analysis. The existence of two different binding region oligosaccharide structures was established: The first structure contains one terminal fucose, two mannosine residues and one N-acetylglucosamine at the reducing end. In the second structure one N-acetylglucosamine is bound to the protein backbone and substituted with branched 3,6-di- O- αmannosyl- β-mannose. Both terminal α-mannosine residues bear keratan sulfate chains in the 2-position.