Synthesis of fusion proteins with multiple copies of an antigenic determinant of foot-and-mouth disease virus antibodies

Abstract

A series of four expression plasmids coding for fusion proteins containing foot-and-mouth disease virus (FMDV) sequences was constructed. The fusion proteins contain a large part of β-galactosidase from Escherichia coli preceded (N-terminal) by 1,2,4 or 8 repeats of the antigenic determinant of FMDV consisting of amino acids 137–162 of the capsid polypeptide VP1. All four fusion proteins were efficiently produced in E. coli host bacteria. Immunization of rabbits resulted in FMDV-specific, neutralizing antibodies, the response being dependent on the number of repeats. With enzyme-linked immunosorbent-assay techniques it was shown that the FMDV antigenic determinants are exposed on the surface of the fusion proteins under non-denaturing conditions.