Soluble expression of the type-specific antigen of FMDV of serotype A and preparation of its polyclonal antibody.

To express soluble recombinant type-specific antigen of foot-and-mouth disease virus of serotype A and prepare polyclonal antibody that of type specificity,the recombinant cloning vector pGEM-AVP1 was used as template for PCR to get the coding region of VP1,and the coding region of OmpT signal peptide was added to the upstream of VP1,then the fragment was cloned to pET-30a(+) to get recombinant expression plasmid pET-30a-OmpT-AVP1.The E.coli BL21-(DE3)-plysS was transformed and expressed soluble fused VP1 with the expected molecular weight at 33 000.Purified VP1 was obtained by Ni-NTA His Bind Resin affinity chromatography and could react with the positive sera of guinea pig of the same serotype.New Zealand rabbits were immunized to prepare polyclonal antibody against VP1.Antiserum against VP1 was obtained and polyclonal antibody was characterized by ELISA,Western blot and indirect immunofluorescence assay(IFA).The polyclonal antibody titer was above 1∶12 800 and type-specific.Moreover,the polyclonal antibody could react well with viral antigen in cell culture.Type-specific antigen of foot-and-mouth disease virus of serotype A and its polyclonal antibody were prepared successfully,which will lay a foundation for further antibody and virus detection.