High Level Expression of Porcine Reproductive and Respiratory Syndrome Virus GP5 Gene in Baculovirus System

Porcine reproductive and respiratory syndrome virus(PRRSV)strain CH_la,a Chinese reference strain,was isloated in Beijing suburb in the middle 1990 Its GP5 gene encoded by open reading frame(ORF)5 was cloned and inserted into the baculovirus transfer vector pBlueBacHis B. Sf9 cells were co_transfected by the recombinant transfer plasmid and linear baculovirus DNA.A recombinant baculovirus was obtained after blue_plaque screening and three cycles of plaque_purification.The GP5 gene was confirmed to be expressed in sf9 cells by immunofluorescent staining and Western blot.The expressed recombinant fusion protein with Histag have apparent molecular weight of 22,25,and 30,accounting for 26.4% approximately in whole cellular proteins.