Expression,Purification and Immunogenicity Analysis onVP5 Protein
of Bluetongue Virus Serotype I
In order to analyze the immunogenicity of VP5 protein of bluetonguevirus serotype I(BTV-1),in this paper,the prokaryotic expression vector PET-28a-VP5 was constructed andtransformed into BL21(DE3).After inducible expression by IPTG,the VP5 protein waspurified and analyzed by means of SDS-PAGE and Western-blot. The results showedthat the relative molecular mass of recombinant VP5 protein was about 62 kDa,which was consistent with the expected result. It was found that,by further optimizing,the expression levelof recombinant protein in supernatant was maximum when IPTG was 0.2 mmol/L,the bacteria solution was inducted for 6 hours at the temperature of25℃,and the purity of recombinant VP5 protein throughNi-sepharose purification was about 75%. Then the purified VP5 protein wasimmunized to Balb/c mice at the doses of 40 and 20 μgper mouse respectively,meantime,PBS was set as the negative control. The serum samples were testedby indirect ELISA after being immunized for 3 times. It was concluded that thespecific antibody against VP5 protein appeared in immunized mice with high orlow dose. In addition,it was found that inactivatedBTV-1 could specifically react with the serum of immunized mice with VP5protein by DOT-ELISA test,indicating that theimmunogenicity of recombinant VP5 protein was good,whichlaid the foundation for further research on BTV.