Expression of overlapping fragments of BVDV p80 gene and analysis of antigenicity of expressed protein

Three overlapping fragments A,B and C of p80 gene of bovine viral diarrhea virus(BVDV) were amplified by PCR.PCR products were cloned into the expression vector pGEX-6P1 and the recombinant plasmids pGEX-6P1-p80A,pGEX-6P1-p80B and pGEX-6P1-p80C were transformed into E.coli Rosetta and BL21 cells.The target proteins of 60ku,47ku and 51ku were produced by induction using IPTG at 1.0(mmol/L).Only the p80B protein(289-477aa) reacted with BVDV positive serum in Western-blotting,indicating that an immunodominant region of the p80 protein was defined by the p80B protein.The p80B recombinant fusion protein can be used as the specific diagnosis antigen for ELISA assay.