GP41, a major glycoprotein, identified in the occlusion-derived virions (ODV) of baculoviruses, is required for the egress of nucleocapsids from the nucleus in the pathway of budded virion (BV) synthesis. Using the polymerase chain reaction (PCR), the open reading frame (ORF) of Spodoptera litura nucleopolyhedrovirus (SpltMNPV) gp41 gene was obtained from SpltMNPV genomic DNA. The PCR product was cloned into pMD18-T vector to get the recombinant plasmid (pT-gp41). The gp41 gene was recombined in vitro with prokaryotic expression vector pQE30 and transformed into Escherichia coli M15 [pREP4]. The M15 [pREP4] strain, containing gp41 recombinant plasmid, expressed a 37.9 kDa 6×His-tag fusion protein after induction with 1 mmol/l isopropylthio-β-d-galactoside (IPTG). The fusion protein was purified with a nickel-nitrilotriacetic acid (Ni–NTA) resin column and used as the immunogen to raise GP41-specific antibody. Western blotting analysis indicated that the antibody was suitable to be used for further analysis of GP41 protein.
