Studies on the structural proteins of vaccinia virus. I. Structural proteins of virions and cores.

Radioactively labeled vaccinia virions grown in L cells were dissociated to yield the constituent polypeptide chains, which were then subjected to electrophoresis in polyacrylamide gels. Mechanical fractionation of these gels yielded complex profiles in which at least 17 components, some major, some minor, could be reproducibly identified. The relative mass in each component has been calculated from the amount of radioactivity incorporated. The principal component (VSP-4) accounts for about 28% of the total viral protein mass. Cores derived from virions by chemical treatment contain the principal viral protein component, which is clearly multiple, as well as two minor ones (VSP-1 and VSP-2), which are probably single polypeptide species. These latter two components are the two slowest moving ones, and therefore most probably have the largest molecular weights. Treatment of virions with the nonionic detergent NP 40 liberates one major viral protein component (VSP-6). This component accounts for 18.7% of viral protein, the second highest amount, and is also multiple in nature.