title: Glycosylation of glycoproteins 52 and 65 encoded by the polycythemia-inducing strain of Friend spleen focus-forming virus. Isolation of glycopeptides containing individual glycosylation sites.
abstract: The primary envelope gene product of the polycythemia-inducing strain of Friend spleen focus-forming virus, glycoprotein 52 (gp52), as well as its processed form, glycoprotein 65 (gp65), were isolated from virus-infected normal rat kidney cells metabolically labeled with [2-3H]mannose. Following digestion with trypsin, glycopeptides containing individual N-glycosylation sites were obtained by gel filtration and subsequent reversed-phase high-performance liquid chromatography. N-terminal amino acid sequencing of the glycopeptides demonstrated that only asparagine residues 11 and 26, located in the N-terminal domains of gp52 and gp65, carry carbohydrate substituents, while the potential N-glycosylation sites in the C-terminal portions of the molecules are not used. Carbohydrates attached were liberated by treatment with endo-beta-N-acetylglucosaminidase H or peptide: N-glycosidase F and characterized by high-performance liquid chromatography. The results demonstrated that gp52 carries similar patterns of oligomannosidic glycans in both positions. In gp65, however, asparagine residue 11 is almost exclusively substituted by complete, fucosylated N-acetyllactosaminic oligosaccharides, whereas asparagine residue 26 carries oligomannosidic or truncated N-acetyllactosaminic glycans.
authors.affiliation: Biochemisches Institut am Klinikum der Universität Giessen, Federal Republic of Germany.
authors.forename: K H
authors.initials: KH
authors.lastname: Strube
authors.forename: F
authors.initials: F
authors.lastname: Lottspeich
authors.forename: R
authors.initials: R
authors.lastname: Geyer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D006020:Glycopeptides / Q000302:isolation & purification*; D006023:Glycoproteins / Q000235:genetics* / Q000302:isolation & purification; D006031:Glycosylation; D007668:Kidney; D009052:Leukemia Virus, Murine / Q000235:genetics*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D011086:Polycythemia / Q000382:microbiology*; D011499:Protein Processing, Post-Translational; D051381:Rats; D013155:Spleen Focus-Forming Viruses / Q000235:genetics* / Q000472:pathogenicity; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D006020:Glycopeptides; D006023:Glycoproteins; D010446:Peptide Fragments; D014759:Viral Envelope Proteins