Structural Components of Oriboca Virus

Analysis of purified Oriboca virions by neutral, sodium dodecyl sulfate polyacrylamide-gel electrophoresis indicated the presence of three structural polypeptides designated V-1, V-2, and V-3 on the basis of their relative electrophoretic mobilities in 8% gels. Polypeptides V-2 and V-3 are glycopeptides associated with the virion envelope as demonstrated by the preferential incorporation of labeled glucosamine into the polypeptides and by release of the polypeptides from the intact virion by the nonionic detergent NP-40. Polypeptide V-1 is the protein component of the nucleoprotein core of Oriboca virus as evidenced by the specific incorporation of uridine into the nucleoprotein, its release from the intact virion by NP-40 treatment, and its separation by both rate-zonal and isopycnic density gradient centrifugation from both the intact virion and envelope components. Molecular weights have been tentatively assigned to the polypeptides by extrapolation from the structural polypeptides of Sindbis virus when both are run in the same gel. Polypeptide V-1 has an apparent molecular weight of 20,000 to 23,000; V-2, 30,000 to 32,000; and V-3, 83,000 to 85,000.