BIOGENESIS OF VACCINIA - EVIDENCE FOR MORE THAN 100 POLYPEPTIDES IN THE VIRION

The polypeptides of vaccinia were separated and analyzed by two-dimensional (2-D) gel electrophoresis patterned after that of O'Farrell (1975). Following labeling with [35S]-methionine, [33P]phosphate, or [3H]glucosamine, pure virions were dissociated and subjected to electrophoresis using either isoelectric focussing or nonequilibrium pH gradient conditions in the first dimension and SDS-polyacrylamide slab gels in the second dimension. By this means at least 111 spots, of which 7 or more were basic proteins, were resolved in the autoradiograms. Authenticity of several single spots was established. This included a glycoprotein of molecular weight 34,000 (34 K) labeled with [3H]glucosamine; a phosphorylated basic protein of about 11 K marked with 33PO4; isolated purified surface tubular elements of 58 K; two major core polypeptides of 60 and 62 K derived from larger precursors after proteolytic cleavage; a precursor polypeptide of 25 K known from previous studies with a ts mutant 1085 to undergo cleavage; and an 18 K polypeptide which appears in wild type and ts 1085 infections under circumstances permissive for cleavage. The 2-D analysis therefore reveals that poxviruses are in terms of their polypeptides, even more complex than had been anticipated previously. © 1979.