[High-level expression of human immunodeficiency virus type 1 gp120 protein in E. coli]

In order to improve protein expression and to produce good and cheap diagnostic antigen, the gene fragment (560bp) in N-terminal of gp120 of HIV-1 LAV strain was amplified by PCR. After digested by EcoR I and Sal I, the fragment was cloned into a high-level expression vector pET28a. The recombinant plasmid pET/120 transfecting BL21 (DE3) produced the protein with high-level expression in the host cell BL21(DE3), which was further proved having good antigenicity and high specificity by indirect ELISA and Western-blot assay. The protein expressed was about 50% of the total bacterial protein by SDS-PAGE electrophoresis test. It was highly expressed in the prokaryotic expression system.