Heterogeneity among flavivirus proteins separated in slab gels

35S-methionine-labeled proteins specified in Vero cells by flaviviruses were analysed by SDS-phosphate electrophoresis in polyacrylamide slab gels. The clarity of the profile produced by Kunjin virus permitted designation of the nonstructural proteins, and confirmed the identity of NV21/2; the profile included a protein previously designated V2 (core protein) but now named NV11/2 because it migrates perceptibly faster than V2. Despite a varying background of labeled host proteins, identifiable profiles were obtained for 11 of 12 flaviviruses. The large non-structural proteins NV5 and NV4 migrated at apparently the same rates for all viruses. Profiles of the remaining proteins displayed varying amounts of heterogeneity, notably in the migration of the envelope protein V3 which showed no evidence of subgroup specificity.