在酿酒酵母中表达人血清白蛋白

目的：利用酵母表达系统表达人血清白蛋白（HSA）。方法：用PCR方法扩增HSAcDNA，利用限制性内切酶将含HSA片段定向插入酵母表达质粒pYET中构建分泌型重组表达载体pYET-HSA，通过DNA测序确定构建的融合蛋白基因序列的正确性。用重组质粒转化酿酒酵母感受态细胞，在亮氨酸营养缺陷型培养基上筛选含重组质粒的酵母转化子菌落。培养转化子酵母，表达HSA，经十二烷基硫酸钠．聚丙烯酰胺凝胶（SDS．PAGE）和Westernblot检测表达情况。结果：DNA序列分析显示，编码外分泌型HSA的基因构建成功。免疫印迹和SDS．PAGE检测结果显示，pYET-HSA酵母转化子可在非诱导条件下表达分泌型可溶性HSA。结论：在酿酒酵母中成功表达HSA。

Expression of Human Serum Albumin Protein in Saccharomyces cerevisiae

Objective： To express secretive human serum albumin protein （HSA） using yeast expression system. Methods： A gene encoding HSA was amplified and was directionally subcloned into yeast expression plasmid pYET to construct a recombinant plasmid for HSA expression. Transformants of Saccharomyces cerevisiae containing the recombinant plasmid pYET-HSA was screened on leucine deficient SD medium after transforming the recombinant plasmid into yeast competent cells. The secretive HSA was expressed by culturing the yeast transformants. The protein in the supernatant of culture was analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis （SDS-PAGE）and Western blot. Results： The gene encoding HSA was constructed successfully, and was confirmed by DNA sequencing. The results of Western blot and SDS-PAGE showed that the yeast transformants containing plasmid pYET-HSA could express the secretive HSA without inducing. Conclusion： HAS was successfully expressed in yeast transformants.