Epitope mapping of the outer structural protein VP1 of three different serotypes of foot-and-mouth disease virus.

All overlapping hexapeptides of the outer structural protein VP1 of type O1, type A10, and type C1 were reacted with the appropriate anti-virus, anti-viral subunit and anti-VP1 sera. The results suggest that anti-virus sera may contain activities against viral subunit and VP1 as well as against virus. Furthermore the antigenic peptides associated with the intact virion of all three serotypes are found at similar locations on their respective VP1s, and produced neutralizing activities when used for vaccination. The results further offer an explanation for the often observed cross-reactions between serotypes, especially at the level of the viral subunit and VP1. The reliability of predictions of useful peptides from hydrophilicity profiles and secondary structure predictions is questioned. Predictions based on variation profiles appear to be more useful.