Keratanase digestion of keratan sulphates: characterization of large oligosaccharides from the N-acetyllactosamine repeat sequence and from the non-reducing terminal chain caps

摘要

Keratan sulfate (KS) chains prepared from both bovine irachcal rings ;md bovine femoral head cartilage were digested with the enzyme keratanase from I'xrtulamomix species; large repeat-sequence and rum-reducing terminal oligosaccharides were fractionated and purified using high-performance ion-exchange ehroinalography. The main 0-linkcd peutasulfated hexasaccharide repeat segment, [R6], C3lcNAc(6S)l-' 'Cial(6S)' '(!lcNAc(fiS)' 'Gal(ciS)1 ''CilcNAd/iS)1 Hial-ol and the asiulo p-linked capping pentasulfated heptusaccharide, [C'7], Cial' *'(jk-NAc(6,S)' l(ial(()S)14(ilcNAc(6S)' '(JaKfiS)1'CilcNAc(6S)' (ial-ol have been completely characterized by high-field NMR speetroscopy using one- and two-dimensional methods. Partial 'll assignments are summarized for three homologous series of higher oligosaccharides.