Cloning,expression and purification of E2,N~(pro) of classical swine fever proteins

Two genes encoding proteins E2 and Npro of classical swine fever virus were cloned in this study,respectively,which were inserted in pGEX-6p-1 expression vector.Two prokaryotic recombinant expression plasmids were constructed.The SDS-PAGE showed that all the two recombinant proteins were successfully expressed.The Escherichia coli were crused by ultrasonic method for acquiring proteins.Fusion proteins with GST-tag were processed by affinity chromatography.The protein E2 were expressed in precipitate as inclusion body,and Npro expressed in liquid supernatant as soluble protein.The inclusion body of E2 was denaturated and refolded to get soluble protein.Fusion proteins with GST-tag were purified by affinity chromatography.The Western blot was used to examine reactogenicity of purified proteins.It was found that prokaryotic recombinant protein Npro did not react to CSFV positive serum,but E2 can react with CSFV positive serum.