Optimization of expression of human immunodeficiency virus type 1 envelope gp41 in E coli

Objective To optimize the expression of HIV-1 envelope gp41 in E coli. Methods The HIV-1 06044 gp41 gene encoding 546~683 aa was amplified by PCR and the prokaryotic expression plasmid pET26b-gp41T was constructed.Meanwhile, plasmid pET26b-gp41T (ΔL) lacking the loop (582~627aa) between NHR and CHR of gp41 was also constructed.After identification by sequencing, the plasmids were transformed into E. coli BL21 (DE3) and the protein expression was induced by Isopropyl β-D-1-thiogalactopyranoside (IPTG) and analyzed by polypropylene acyl ammonia gel electrophoresis (SDS-PAGE) and Western Blot.The protein expression condition was optimized. Results The pET26b-gp41T and pET26b-gp41T (ΔL) can express specific gp41 protein.Under 1mmol/L IPTG induction, the gp41T(ΔL) protein expression quantity was higher than gp41T and the best expression was at 37 ℃.Comparing with gp41T, gp41T (ΔL) protein showed better affinity to his antibody. Conclusion We successfully constructed a recombinant plasmid that can express gp41 protein successfully in E coli with well exposure of His-Tag.This will facilitate the production and purification of gp41 immunogen. Key words: HIV-1; Gp41; Prokaryotic expression; Modification