Prokaryotic expression of E protein gene of Japanese encephalitis virus (JEV) and establishment of an indirect ELISA for detection of antibody against JEV.

According to the E gene sequence of Japanese encephalitis virus(JEV),a pair of primers was designed.With the primers,the objective gene was amplified with 1500bp in size.Then the amplified E gene was cloned into prokaryotic expression vector pET-28a(+) to construct recombinant plasmid.The plasmid was transformed into BL21(DE3) competent cell,and the E protein was expressed highly with 53ku approximately in molecular weight.Western-blot analysis showed that E protein could react with positive swine sera.Based on the expressed protein an indirect ELISA was established to detect JEV antibody in swine serum.The coincidence rate of the developed indirect ELISA was 92% with the kit made by Wuhan Keqian Biologicals Company,indicating that the developed indirect ELISA was sensitive and specific.