Structural Proteins of Foot-and-Mouth Disease Virus

A mutant of the virus of foot-and-mouth disease (O type) was studied, and shown by electrophoresis in SDS-polyacrylamide gels to contain equimolar proportions of four polypeptides with mol. wts. of 34, 20, 17 and 14 x 10³. Two minor components were also present with mol. wts. of 51 and 25 x 10³ and in the molar ratio of 0.07 and 0.28. Only the polypeptide of mol. wt. 34 x 10³ was labelled when the intact virus was iodinated. This polypeptide was sensitive to the action of trypsin and showed leucine as the N-terminal amino acid. Our own and other results are discussed in terms of virus structure.