This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Barban, S. Search for Related Content PubMed PubMed Citation Articles by Barban, S.

 Previous Article  |  Next Article 

J Virol. 1973 June; 11(6): 971-977
Copyright © 1973 American Society for Microbiology. All Rights Reserved.

Electrophoretic Differences in the Capsid Proteins of Simian Virus 40 Plaque Mutants

¹ Laboratory of Biology of Viruses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20014

ABSTRACT

The structural proteins of three mutants of simian virus 40 (SV40) which differ in plaque size, temperature sensitivity, oncogenicity, host cell restriction, and immunological properties were studied. The polypeptide components of these SV40 strains could not be distinguished by their polyacrylamide gel electrophoretic patterns. When the dissociated virions of two of the mutants were analyzed by the isoelectric focusing technique in a urea gradient, the capsid protein peaks were found to differ significantly in their isoelectric points. The capsid protein of the small-plaque mutant had an isoelectric point of pH 6.51 as compared with pH 6.28 for the large-plaque strain. Isoelectric focusing of the isolated capsid protein revealed three components, a single major subunit and two minor forms. The coat proteins of two of the mutants, small-plaque and minute-plaque strains, were indistinguishable by this technique. The capsid protein peaks obtained by isoelectric focusing were further analyzed by polyacryalmide gel electrophoresis.