Research On Expression And Antigenicity Of Core Antigen Site Of E0 Structure Proteins Of Classical Swine Fever Virus

Classical swine fever(CSF), a high contagious and often fatal viral disease of swine, brings severe economic losses to the pig farms. CSFV is a member of Pestivirus of Flavivirus, which genome codes four structual proteins(C,E0,E1,E2)and at least seven nonstructural proteins(Npro,P7,NS2,NS3,NS4A,NS4B,NS5A,NS5B). E0, an important structural protein with RNase activity, can induce immune inhibition by causing cell apoptosis of lymphocyte and epithclium.The gene fragment of E0 191~227 amino acid of CSFV were amplified by polymerase chain reaction (PCR) , and cloned into expression vector pET-30c(+).The recombinant plasmids 30C-E0-1725 were obtained successfully, and the recombinant protein was expressed with high efficiency in E.coli BL21 transformed by 30C-E0-1725 after induction with IPTG. The fusion protein has a correct molecular weight as expected by SDS-PAGE analysis. The expressed and purified protein showed specific reactivity with positive serum against CSFV in Western blot. The indirect ELISA detecting method was established by taking recombinant protein as the antigen, which is base for the further development of ELISA diagnosis kit of recombinant E0 protein.