Peptide composition of Sindbis virus variants

The peptide composition of variants of Sindbis virus which differ in plaque-type, elution pattern from calcium phosphate columns and virulence in mice was analyzed. Differences in peptide number or composition were not detected in these variants. Since the Sindbis virion has an outer lipoprotein envelope which is derived at least in part from the plasma membrane of the host cell, peptide composition of purified chicken embryo membranes was analyzed. In contrast to the virions, the number of peptide units in the host cell membrane were too numerous to give resolution.