Structural proteins of adenoviruses: XI. Purification of three low molecular weight virion proteins of adenovirus type 2 and their synthesis during productive infection

Abstract

Three low molecular weight structural proteins have been purified from adenovirus type 2 virions. These proteins, which correspond to polypeptides VI, VIII, and IX as defined by mobility is SDS-polyacrylamide gels (Maizel, 1971; Everitt et al., 1973), have been purified to homogeneity by preparative polyacrylamide gel electrophoresis, gel exclusion, and ion exchange chromatography. The three proteins are immunologically distinct and do not cross react with the main capsid and core proteins as revealed by immunodiffusion. Their amino acid compositions differ from those of the major capsid and core proteins and protein VI is rich in glycine (26%) and serine (22%). Pulse-chase experiments suggest that proteins VI and VIII may be derived by cleavage from larger precursors, whereas protein IX appears to be a primary translation product. Late in productive infection, protein IX seems to be synthesized in excess of the amount required for virus assembly. No excess pool of proteins VI and VIII could be revealed.