Structural proteins of vesicular stomatitis viruses

Abstract

Three major and three minor structural proteins were identified by polyacrylamide gel electrophoresis of purified infectious virions of the Indiana serotype of vesicular stomatitis (VS) virus disrupted with acetic acid, 0.5 m urea, sodium dodecyl sulfate (SDS), and 2-mercaptoethanol. Molecular weights of the six virion proteins were estimated by comparative electrophoretic migration of known marker proteins in the presence of SDS. The following values were obtained: major proteins P6 congruent with 34,500, P5 congruent with 59,500, and P4 congruent with 81,500; minor proteins P3 congruent with 140,000, P2 congruent with 186,000, and P1 congruent with 275,000. P1 did not disaggregate in 8 m urea, but P2 and P3 did. The possibility that P1 is an uncleaved large polypeptide chain could not be ruled out. Six identical protein components were dissociated from Indiana VS virions grown in chick and mouse cells; no cellular proteins could be detected in purified virions. Of six proteins identified in virions of the New Jersey serotype, only the smallest protein (P6) could be distinguished from any of the six proteins of the Indiana serotype on the basis of migration in SDS gels. The defective T particles of Indiana VS virus contained the same six proteins in essentially the same proportions as those of the infectious B virions. Only P6 and P5 could be cleanly separated by preparative gel electrophoresis.