title: "Linkage region" sequences of heparins and heparan sulfates: detection and quantification by nuclear magnetic resonance spectroscopy.
abstract: The (13)C NMR spectra of most heparin and heparan sulfate preparations display minor signals not attributable to the glycosaminoglycan chains of these polysaccharides. These signals have been "concentrated" in oligosaccharides isolated from an acid hydrolyzate of heparin and shown to arise from the sequence GlcA-Gal-Gal-Xyl of the "linkage region" (LR) connecting the carbohydrate chains to the peptide chains in the original proteoglycans. Mono- and two-dimensional (1)H and (13)C NMR analysis of the major oligosaccharide (LR-OLIGO) indicated the prevalent structure GlcA-GlcNAc-GlcA-Gal-Gal-Xyl, where GlcNAc is partially 6-O-sulfated. (13)C NMR signals at 84.6 and 85.0 ppm, arising from C-3 of the two Gal residues, lend themselves to easy detection and quantification of the linkage region in heparins and heparan sulfates and can be used to assess the importance of the LR in the modulation of various biological activities of these glycosaminoglycans.
authors.affiliation: Istituto di Ricerche Chimiche e Biochimiche "G. Ronzoni,", via G. Colombo, Milan, 81-20133, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Iacomini
authors.forename: B
authors.initials: B
authors.lastname: Casu
authors.forename: M
authors.initials: M
authors.lastname: Guerrini
authors.forename: A
authors.initials: A
authors.lastname: Naggi
authors.forename: A
authors.initials: A
authors.lastname: Pirola
authors.forename: G
authors.initials: G
authors.lastname: Torri
mesh_terms: D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002417:Cattle; D006493:Heparin / Q000737:chemistry*; D006497:Heparan Sulfate / Q000737:chemistry*; D007413:Intestinal Mucosa; D008168:Lung; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D013552:Swine
chemical_list: D006493:Heparin; D006497:Heparan Sulfate; D009844:Oligosaccharides