Isolation of the structural polypeptides of foot-and-mouth disease virus and analysis of their C-terminal sequences

Abstract

The three polypeptides—VP 1, VP 2 and VP 3—which comprise approximately 91% of the protein of foot-and-mouth disease virus, type A 12-119, were separated by polyacrylamide gel electrophoresis (PAGE) in sufficient purity and quantity for determination of their amino acid compositions as well as for analysis of their C-terminal sequences and molecular weights by reaction with carboxypeptidase-A. At least seven distinct differences in amino acid compositions were observed among the three polypeptides, but their average composition was nearly identical to that of the total protein of the virus, VP 0–4. C-Terminal amino acid sequences for VP 1 and VP 3 appear to to be (—serine-glutamine) and (—glutamine-alanine-leucine), respectively, and the C-terminal amino acid of VP 2 is probably glutamic acid. Molecular weights for VP 1 and VP 3 calculated from C-terminal data were in the 27,500–31,000 dalton range compared with values of 28,500 determined previously by PAGE.