Antigenicity and immunogenicity of synthetic peptides of foot-and-mouth disease virus.

Peptides reactive with two neutralizing monoclonal antibodies raised against intact foot-and-mouth disease virus A10 were identified with the aid of all overlapping (hexa)peptides of the outer structural viral protein VP1 and located on the viral surface. Using this procedure, it was possible to define those amino acids within a peptide which were critical in the binding of antibody to that peptide. One eight amino acid long peptide, containing six such amino acids, was virtually indistinguishable from viral antigen in its ability to bind monoclonal antibody as determined by competition tests. Another peptide, which was able to induce neutralizing activity as well, showed no competition and possessed fewer amino acids contributing to binding. This peptide appeared to be an incomplete epitope. Comparison of our data with those of others suggests that this may apply commonly to the reactive peptides described.