title: (1)H and (15)N NMR Characterization of the Amine Groups of Heparan Sulfate Related Glucosamine Monosaccharides in Aqueous Solution.
abstract: Glucosamine is an important constituent of the heterogeneous glycosaminoglycans heparin and heparan sulfate occurring in N-acetylated and N-sulfated forms, and as the unmodified amine. Though the (1)H and (15)N NMR chemical shifts of N-acetyl- and N-sulfoglucosamine residues have been extensively characterized, this study provides the first direct NMR characterization of the amine groups of glucosamine and 3-O-sulfoglucosamine in aqueous solution. The solvent exchange properties of the amine protons are examined, and the possibility of a salt bridge between the sulfate and amine groups of 3-O-sulfoglucosamine is explored through (1)H NMR pKa measurements but is not supported by the experimental results.
authors.affiliation: Department of Chemistry, University of California - Riverside, Riverside, California 92521, United States.
authors.forename: Consuelo N
authors.initials: CN
authors.lastname: Beecher
authors.affiliation: Department of Chemistry, University of California - Riverside, Riverside, California 92521, United States.
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Larive
mesh_terms: D000588:Amines / Q000737:chemistry*; D005944:Glucosamine / Q000737:chemistry*; D006497:Heparan Sulfate / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009005:Monosaccharides / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000588:Amines; D005944:Glucosamine; D006497:Heparan Sulfate; D009005:Monosaccharides; D014867:Water