Construction of engineering yeast strain expressing gag-gp120 chimeric gene of HIV-1 and optimization of the expression condition

Objective: To make up an engineering yeast strain expressing HIV-1 gag-gp120 chimeric gene. Methods: gag-gp120 chimeric gene was inserted into a yeast expression vector pHILS1 and the expression plasmid pHILGP was constructed. After the plasmids were linearized and electrotransformed into the yeast strain GS115, an engineering yeast strain was screened by PCR. SDS-PAGE, ELISA analysis of expressed products, and the expression condition was optimized. Results: An engineering yeast strain was successfully established. The amount of the expressed protein was approximately 13% of the soluble protein in the supernatant. The expressed protein could reacted with HIV-1 positive serum, but the relative molecular mass (M_r) of gag-gp120 fusion protein was smaller than the expected value. Conclusion: The expressed protein has good antigen specificity and is exist in the supernatant of the culture which favors isolation and purification of interest protein.