[Yeast surface display of HIV-1 gp41 and expression enhancement]

HIV-1 gp41 has been successfully anchored on the cell surface of yeast Saccharomyces cerevisiae by yeast cell-surface display systems using His-tag for the detection of protein expression. Gp41 activity has been detected by gp41 monoclonal antibody. The vector for gp41 yeast display has been constructed as follows: the gene-encoding gp41 was amplified by PCR using pMD18T-gp41 as a template, and then inserted into shuttle vector pICAS-His by restriction enzyme digestion. Next, the vectors were introduced into Saccharomyces cerevisiae MT8-1. After cultivation, recombinant cells were immunofluorescence labelled. The bright green cells were observed by the microscopy indicating the proteins have been displayed on the cell surface successfully, flow cytometry convinced that gp41 has been folded correctly on the cell surface. Then different concentrations of initial glucose were used to enhance the expression of protein. gp41 has been expressed by 82.46% yeast cells as the concentration of glucose was 1%. Protein expression was depressed when the concentration was increased.