title: The alkali-labile linkage between keratan sulphate and protein.
abstract: Keratan sulphate was isolated from adult intervertebral disc in 90% yield by sequential digestion of the whole tissue with papain, Pronase and Proteus vulgaris chondroitin sulphate lyase. Treatment of this preparation with alkali cleaved a glycosidic bond between N-acetylgalactosamine and threonine and produced, by an alkali-catalysed ;peeling' reaction, an unsaturated derivative of N-acetylgalactosamine which reacted as a chromogen in the Morgan-Elson reaction, but remained covalently bonded to the keratan sulphate chain. This derivative was reduced and labelled by alkaline NaB(3)H(4). The substituent at position 3 of N-acetylgalactosamine in the keratan sulphate-protein linkage was identified as a disaccharide, N-acetylneuraminylgalactose, which was isolated from the reaction mixture after alkali treatment.
mesh_terms: D000478:Alkylation; D000596:Amino Acids; D000818:Animals; D001322:Autoanalysis; D001894:Borohydrides; D002417:Cattle; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D002854:Chromatography, Paper; D005688:Galactosamine / Q000031:analogs & derivatives; D006025:Glycosaminoglycans; D008970:Molecular Weight; D010206:Papain; D011402:Pronase; D011485:Protein Binding; D013429:Sulfatases; D013912:Threonine
chemical_list: D000596:Amino Acids; D001894:Borohydrides; D006025:Glycosaminoglycans; D013912:Threonine; D005688:Galactosamine; D013429:Sulfatases; D010206:Papain; D011402:Pronase