title: Identification of the amino terminal subunit of the glycoprotein of Borna disease virus.
abstract: The only surface membrane glycoprotein of Borna disease virus (BDV) is synthesized as a polypeptide with a molecular mass of 57 kDa and N-glycosylated to a precursor glycoprotein (GP) of about 94 kDa. It is processed by the cellular protease furin into the C-terminal membrane-anchored subunit GP-C, also known as gp43, and a presumptive N-terminal subunit GP-N, that is highly glycosylated and has a molecular mass of about 51 kDa. However, up to now the latter remained undetected in BDV-infected material. We describe a novel approach to identify glycan masked linear antigenic epitopes. In the present study, GP-N was identified in BDV-infected cells by a combination of lectin precipitation, enzymatic deglycosylation on blot and immunochemistry using an N-terminal specific antiserum. The GP-N has an apparent molecular mass of 45-50 kDa in its glycosylated form and 27 kDa in its deglycosylated form. N-glycan analysis revealed that the precursor GP contains only mannose-rich N-glycans, whereas GP-N and GP-C contain mannose-rich and complex-type N-glycans.
authors.affiliation: Institut für Virologie der Philipps-Universität Marburg, Marburg, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Kiermayer
authors.forename: Ina
authors.initials: I
authors.lastname: Kraus
authors.forename: Jürgen A
authors.initials: JA
authors.lastname: Richt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Garten
authors.forename: Markus
authors.initials: M
authors.lastname: Eickmann
mesh_terms: D000818:Animals; D001891:Borna disease virus / Q000276:immunology; D002460:Cell Line; D002522:Chlorocebus aethiops; D004285:Dogs; D006023:Glycoproteins / Q000032:analysis / Q000737:chemistry* / Q000276:immunology; D006026:Glycoside Hydrolases; D015151:Immunoblotting; D037102:Lectins / Q000378:metabolism; D008358:Mannose / Q000032:analysis; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry; D021122:Protein Subunits; D014709:Vero Cells; D014764:Viral Proteins / Q000032:analysis / Q000737:chemistry* / Q000276:immunology
chemical_list: D006023:Glycoproteins; D037102:Lectins; D011134:Polysaccharides; D021122:Protein Subunits; D014764:Viral Proteins; D006026:Glycoside Hydrolases; D008358:Mannose