HIV-1 gp41的酵母表面展示及表达优化

Yeast Surface Display of HIV-1 gp41 and Expression Enhancement

摘要:

以His标签检测蛋白的表达, 利用酿酒酵母表面展示系统, 成功地将HIV-1 gp41片段锚定在酵母表面, 并检测到gp41的活性。以pMD18T-gp41为模板, 通过PCR技术克隆了gp41基因, 将gp41基因通过双酶切连接到载体pICAS-His上,构建了gp41酵母表面展示载体, 并将其转化至酿酒酵母(Saccharomyces cerevisiae)MT8-1中。重组菌经培养, 利用免疫荧光染色方法进行染色, 显微镜观察发现重组酵母细胞表面有绿色荧光, 流式细胞仪结果进一步证实gp41正确折叠展示于酵母细胞表面。采用不同浓度的葡萄糖培养基进行表达优化。当葡萄糖浓度为1%时, 82.46%的酵母细胞表达了gp41抗原; 随着葡萄糖浓度升高, 蛋白表达受到抑制。

关键词:酵母展示技术, HIV-1 gp41, 免疫荧光染色, 流式细胞仪

Abstract:

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.

Key words:yeast display, HIV-1 gp41, immunofluorescence labeling, flow cytometry