PROTEINS OF PARAINFLUENZA VIRUS SV5 .2. SEPARAION OF VIRION POLYPEPTIDES BY POLYACRYLAMIDE GEL ELECTROPHRESIS

The polypeptides of isolated, purified SV5 nucleocapsid and of SV5 virions dissociated with sodium dodecyl sulfate have been separated by polyacrylamide gel electrophoresis. The nucleocapsid contains a single polypeptide. A total of six polypeptides, 2 major and 4 minor bands, have been found in the SV5 virion. The nucleocapsid protein represents one of the major polypeptides, and the other five are presumably associated with the viral envelope. Similar results have been obtained with SV5 virions grown in four different cell types. Estimation of the molecular weights of the viral proteins based on coelectrophoresis with marker proteins indicate that the nucleocapsid polypeptide has the lowest molecular weight, ∼43,000. The molecular weights of the other five viral polypeptides range from approximately 50,000 to 76,000. © 1969.