title: Carbohydrate structure of glycoprotein 65 encoded by the polycythemia-inducing strain of Friend spleen focus-forming virus.
abstract: The secondary envelope-gene product, glycoprotein 65 (gp65), of the polycythemia-inducing variant of Friend spleen focus-forming virus (F-SFFVp) was isolated from F-SFFVp-infected normal rat kidney cells cultivated in the presence or absence (-Glc) of glucose. Oligosaccharide side chains present were sequentially liberated by treatment of tryptic glycopeptides with endo-beta-N-acetylglucosaminidase H and peptide N-glycosidase F and fractionated by high-performance liquid chromatography. The glycans were characterized by digestion with exoglycosidases, by chromatographic comparison with oligosaccharide standards and by methylation analysis. The results demonstrate that gp65 contains oligomannosidic, hybrid and N-acetyllactosaminic glycans. The oligomannosidic glycans represent the same partially glucosylated species with six to nine mannose residues present in F-SFFVp gp52, the biosynthetic precursor of gp65 [Strube, K.-H. Schott, H.-H. and Geyer, R. (1988) J. Biol. Chem. 263, 3762-3771]. Oligosaccharides of the hybrid type were found to comprise one sialylated lactosamine unit and three or four alpha-linked mannose residues. Analysis of the N-acetyllactosaminic glycans revealed that gp65 carries fucosylated, partially sialylated bi-antennary, tri-antennary and tetra-antennary oligosaccharides, in addition to incomplete species. The glycosylation of gp65(-Glc) is characterized by the presence of oligomannosidic glycans with five to nine mannose residues, similar hybrid-type species and by increased amounts of incomplete N-acetyllactosaminic oligosaccharides, a decrease in sialylation and the lack of tetra-antennary species.
authors.affiliation: Biochemisches Institut am Klinikum, Universität Giessen.
authors.forename: K H
authors.initials: KH
authors.lastname: Strube
authors.forename: R
authors.initials: R
authors.lastname: Geyer
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D005622:Friend murine leukemia virus / Q000032:analysis*; D006023:Glycoproteins / Q000302:isolation & purification; D006868:Hydrolysis; D008358:Mannose / Q000032:analysis; D008745:Methylation; D015394:Molecular Structure; D009005:Monosaccharides / Q000032:analysis; D009844:Oligosaccharides / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis; D014759:Viral Envelope Proteins / Q000302:isolation & purification
chemical_list: D002241:Carbohydrates; D006023:Glycoproteins; D009005:Monosaccharides; D009844:Oligosaccharides; D011134:Polysaccharides; D014759:Viral Envelope Proteins; D008358:Mannose