title: Release of O-linked sugar chains from glycoproteins with anhydrous hydrazine and pyridylamination of the sugar chains with improved reaction conditions.
abstract: A method for preparation of pyridylamino (PA-) derivatives of O-linked sugar chains from glycoproteins was developed. A glycopeptide containing O-linked Gal beta 1-3GalNAc was prepared from fetuin and treated with anhydrous hydrazine followed by N-acetylation of free amino groups. Sugar chains released were pyridylaminated with improved reaction conditions and excess reagents were removed by gel filtration. Gal beta 1-3GalNAc-PA obtained together with PA-Gal as a by-product was quantified by HPLC. Conditions for the hydrazine treatment were investigated and the treatment at 40 degrees C for 350 h gave the best results for releasing O-linked sugar chains. The total yield of Gal beta 1-3GalNAc-PA from the glycopeptide was 53% under the established conditions and that of PA-Gal was 18%. The present method was applied to a glycoprotein, and the expected PA-O-linked sugar chains were obtained. Under these conditions, N-linked sugar chains were also released.
authors.affiliation: Department of Chemistry, Osaka University College of Science.
authors.forename: N
authors.initials: N
authors.lastname: Kuraya
authors.forename: S
authors.initials: S
authors.lastname: Hase
mesh_terms: D000116:Acetylgalactosamine / Q000737:chemistry; D000631:Aminopyridines / Q000737:chemistry*; D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000138:chemical synthesis / Q000737:chemistry*; D002417:Cattle; D006020:Glycopeptides / Q000737:chemistry; D006023:Glycoproteins / Q000138:chemical synthesis / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry*; D008969:Molecular Sequence Data; D013696:Temperature; D013997:Time Factors
chemical_list: D000631:Aminopyridines; D002241:Carbohydrates; D006020:Glycopeptides; D006023:Glycoproteins; D006834:Hydrazines; C029424:hydrazine; D000116:Acetylgalactosamine