title: Characterization of N- and O-linked oligosaccharides of glycoprotein 350 from Epstein-Barr virus.
abstract: Glycoprotein 350 (gp350), the major Epstein-Barr Virus (EBV) envelope glycoprotein, has extensive N- and O-linked oligosaccharide chains. To characterize these oligosaccharide chains, [3H]glucosamine-labeled gp350 was isolated from an EBV transformed marmoset lymphoblastoid cell line (B95-8) induced to replicate EBV. Radiolabeled pronase-glycopeptides were fractionated by serial affinity chromatography and O-linked oligosaccharides released by mild alkaline borohydride treatment. Virtually all (99%) N-linked oligosaccharides were of complex type, with a predominance of tri-tetraantennary versus diantennary chains. A significant portion (28%, in term of radioactivity) of the tri-tetraantennary chains bound to leucoagglutinin-agarose, indicating an additional branch in beta(1-6)-linkage to the trimannosyl core. N-linked oligosaccharides with such a branching pattern have not been previously described in any herpesvirus glycoprotein, but have been associated with neoplastic transformation. Half of [3H]glucosamine incorporated into gp350 was recovered in O-linked oligosaccharides. The smallest chains have a core beta Gal-GalNAc disaccharide structure. Most O-linked chains have two to three N-acetylglucosamine and one N-acetylgalactosamine residues, besides the N-acetylgalactosamine residue located at the terminal reducing end, suggesting a di- or tri- N-acetyllactosamine structure. Consistent with such a structure, the size of these chains, after sialic acid removal, was that of an heptasaccharide or larger.
authors.affiliation: Dipartimento di Patologia Sperimentale, Università degli Studi di Bologna, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Serafini-Cessi
authors.forename: N
authors.initials: N
authors.lastname: Malagolini
authors.forename: M
authors.initials: M
authors.lastname: Nanni
authors.forename: F
authors.initials: F
authors.lastname: Dall'Olio
authors.forename: G
authors.initials: G
authors.lastname: Campadelli-Fiume
authors.forename: J
authors.initials: J
authors.lastname: Tanner
authors.forename: E
authors.initials: E
authors.lastname: Kieff
mesh_terms: D002846:Chromatography, Affinity; D003208:Concanavalin A; D006031:Glycosylation; D004854:Herpesvirus 4, Human / Q000032:analysis*; D008562:Membrane Glycoproteins / Q000032:analysis*; D008970:Molecular Weight; D009844:Oligosaccharides / Q000032:analysis; D011499:Protein Processing, Post-Translational; D014759:Viral Envelope Proteins / Q000032:analysis*
chemical_list: D008562:Membrane Glycoproteins; D009844:Oligosaccharides; D014759:Viral Envelope Proteins; D003208:Concanavalin A