Purification and immunogenicity of fusion VP1 protein of foot and mouth disease virus

A procedure has been developed to purify foot and mouth disease virus (FMDV) VP1 surface antigens from recombinant Escherichia coli. The VP1 antigens are expressed as fusion proteins derived from the E. coli Trp operon and VP1 surface protein of FMDV. The procedure is capable of recovering greater than 96% of the desired product at a purity of greater than 96%. The resulting antigens induce significant levels of virus-neutralizing antibody in guinea pigs and cattle as determined by a mouse protection assay [Skinner, H.H. (1952) Proc. Int. Vet. Congr., 15th 1, 195]. E. coli contaminants have a deleterious effect on ion-exchange chromatography as well as immunogenicity of the expressed fusion VP1 antigens. The method presented removes significant E. coli contaminants, yielding fusion VP1 proteins which are immunogenically potent. In particular, virus neutralization titers at 100-micrograms dosage of the fusion VP1 proteins of the O1 and A24 serotypes are similar to that induced by the natural VP1 proteins isolated from FMD virions.