Biochemical and structural studies with neutralizing antibodies raised against foot-and-mouth disease virus

The function of a loop exposed on the aphthovirus capsid (the G-H loop of p rotein VP1) has been explored by combining genetic and structural studies w ith viral mutants. The loop displays a dual function of receptor recognitio n and interaction with neutralizing antibodies. Remarkably, some amino acid residues play a critical role in both such disparate functions. Therefore residues subjected to antibody pressure for variation may nevertheless main tain a role in receptor recognition for which invariance is a requirement. Evolution of FMDV in cell culture may relax the requirements at this site a nd allow further increase of antigenic diversification. Essential residues at one stage of virus evolution may become dispensable at another not very distant point in the evolutionary landscape. Implications for FMDV evolutio n and vaccine design are discussed. (C) 1999 Elsevier Science B.V. All righ ts reserved.