Prokaryotic Expression of GP5 Protein of PRRSV and Preparation of Its Polyclonal Antibody
In order to express the glycosylated envelope protein GP5 of porcine reproductive and respiratory syndrome virus(PRRSV)in vitro,and to prepare its polyclonal antibody,GP5 gene was amplified by RT-PCR by taking the RNA of PRRSV PC vaccine strain as a template,then cloned into the prokaryotic expression vector pet-32a(+)to construct the recombinant expression vector of pET-32a-GP5. After enzyme digestion and sequencing analysis,the positive recombinant plasmid was transformed into E. coli BL21(DE3)cells,and induced by IPTG at low temperature. The PRRSV GP5 protein was purified by affinity chromatography,and then was vaccinated into Beijing white rabbit to prepare polyclonal antibody,then enzyme linked immunosorbent assay(ELISA)and indirect immunofluorescence analysis(IFA)were carried out. The results showed that the expressed GP5 prokaryotic protein was available in soluble supernatant and inclusion body,with a molecular weight of approximate 30 kDa;the ELISA titer of the polyclonal antibody against GP5 protein was up to 1:64 000,and it was shown that PRRSV could react with the polyclonal antibody. In conclusion,good biological materials were provided for establishing serological detection methods for PRRSV through successful preparation of recombinant PRRSV GP5 protein and its polyclonal antibody.