STRUCTURE OF THE KERATAN SULFATE CHAINS ATTACHED TO FIBROMODULIN ISOLATED FROM BOVINE TRACHEAL CARTILAGE - OLIGOSACCHARIDES GENERATED BY KERATANASE DIGESTION

The structure of the repeat region and chain caps of the N-linked kera tan sulphate chains attached to bovine tracheal cartilage fibromodulin has been examined. The chains were fragmented by keratanase digestion , the resultant oligosaccharides isolated by strong anion-exchange chr omatography, and their structures determined using high-field H-1-n.m. r. spectroscopy. The chains were found to possess the following genera l structure: [GRAPHICS] All of the capping oligosaccharides isolated t erminate with alpha(2-3)-linked N-acetylneuraminic acid. No alpha(2-6) -linked N-acetylneuraminic acid chain terminators, nor any fucose, alp ha(1-3)-linked to N-acetylglucosamine along the repeat region, were de tected. This work demonstrates that the structure of the repeat region and chain caps of N-linked keratan sulphate attached to fibromodulin isolated from bovine tracheal cartilage is identical with that of O-li nked keratan sulphate chains attached to aggrecan derived from non-art icular cartilage.