Envelope protein of the flavivirus Kunjin is apparently not glycosylated.

The envelope protein E (formerly designated V3) of the flavivirus Kunjin was not labelled with radioactive galactose, mannose or glucosamine during virus growth in Vero cells. On electrophoresis through polyacrylamide gels containing SDS, the envelope (E) protein migrated more rapidly than related intracellular virus-specified glycoproteins. Furthermore, E had a density in CsCl solution consistent with that of a protein lacking carbohydrate, and did not bind to concanavalin A-agarose. In contrast, the envelope glycoprotein of Murray Valley encephalitis virus (MVEV) did bind to concanavalin A under similar conditions and was readily labelled with radioactive mannose. These results suggested that the E protein of Kunjin virus was not glycosylated, a feature not shared with MVEV and West Nile virus (WNV), whose properties were consistent with the presence of oligosaccharides attached to the envelope proteins. When Kunjin virions were labelled with radioactive glucosamine, the label was contained in GP19 (formerly NV2). The glycopeptides derived by Pronase digestion of GP19 from Kunjin virions were larger than those derived from GP19 obtained from infected cells.