Research On The Vector Construction Expressing Porcine Parvovirus (SC1) VP2 Gene

The VP2 gene which cloned into pMD-T was inserted into prokaryotic vector PET30a+ to obtain a recombinant plasmid PET30a+-VP2. The plasmid PET30a+-VP2 was transformed into E.coli.BL21(DE3). The target protein was not detectable by SDS-PAGE analysis after induction by IPTG.。 We changed the incubation condition of BL(DE3), the protein of interest was not detected too. So we suggest that the VP2 gene of PPV is not suitable for expression in E.coli, or the expression level of VP2 protein is too low to be detected.The VP2 gene which cloned into pMD-T was inserted into eukaryotic vector pEGFP-C1 to obtain a recombinant plasmid pEGFP-VP2. The pEGFP-VP2 was transfect to IBRS-2 cell by calcium phosphate co-precipitation. Positive clones were obtained with G418. The expression of VP2 gene was detected by fluoroscopy and SDS-PAGE, Western-blot. The results showed that the plasmid can express in IBRS cell. The expressed product was salted out. The purified product was used as antigen to establish an indirect ELISA to detect antibodies against PPV. Clinical samples of sera were detected and compared with HI test , this ELISA method was proved to be more sensitive .