Studies on the carbohydrate-protein linkage region in bovine corneal keratan sulfate. I. Isolation of linkage-region glycopeptides under mild conditions.
Isolation of linkage-region glycopeptides from corneal peptidokeratan sulfate was attempted under mild conditions. Peptidokeratan sulfate, which had been found in advance of the present study to contain three mannose residues per chain as a major component of the carbohydrate-protein linkage region, was digested with Pseudomonas endo-beta-galactosidase. The disaccharide-repeating chain was partially hydrolyzed, and almost all the galactose and N-acetylglucosamine residues were found in oligosaccharides of various sizes. The resulting linkage region-enriched glycopeptides were separated by gel filtration from these oligosaccharides and then fractionated by DEAE-cellulose and Dowex 50 chromatography with the guidance of the mannose content. The glycopeptides obtained were highly enriched in the linkage region and a large portion of them was free from sulfate groups, suggesting that they could be used to elucidate the structure of the linkage region.
D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D002627:Chemistry, Physical; D003315:Cornea / Q000032:analysis*; D005136:Eye Proteins; D006020:Glycopeptides / Q000302:isolation & purification*; D006025:Glycosaminoglycans; D006868:Hydrolysis; D007632:Keratan Sulfate; D011485:Protein Binding; D001616:beta-Galactosidase
D005136:Eye Proteins; D006020:Glycopeptides; D006025:Glycosaminoglycans; D007632:Keratan Sulfate; D001616:beta-Galactosidase