Electrophoretic analysis of capsid and non-capsid polypeptides of echovirus 12, and selective inhibtion of the formation of virus particles by actinomycin D.

Electrophoretic analysis of purified echovirus virus particles yielded four polypeptides of mol. wt. 37000, 30000, 25000 and 7600. The 75S empty capsids of echovirus 12 lack the 25000 and 7600 mol. wt. polypeptides, and possess polypeptides of 41000 mol. wt. A total of 14 virus-induced polypeptide species was found in the cytoplasm of infected cells. Actinomycin D reduced the synthesis of virus, virus RNA, and virus polypeptides and also reduced the proportion of virus particles to empty capsids in the virus yields.