摘要
将ADH2基因的UAS与带有不同长度缺失上游区的SUC3基因融合,构建成4种具有不同融合启动子的SUC2基因的表达质粒YRD1101.YFD110△9.YFD110△17、YFD110△11。将这些质粒及对照表达质粒YFD26△1.YFD25转化酵母菌Y33,在阻遏与去阻遏培养条件下,对各种转化子所产生的蔗糖酶进行了活性测定和组分分析。结果表明:在葡萄糖去阻遏生长条件下,YFD110△1的启动子组合中UASsuc2和UASADH2对SUC2基因的表达有协同激活作用。在阻遏条件下Y33/YFD110△1与Y33/YFD110△9、Y33/YFD26△1、Y33/YFD25一样,均表达很低的糖基化蔗糖酶,3种去阻遏培养条件比较说明。
By fusing the upstream activation sequence (UAS) of ADH2 gene to the 5' end of a series of deletions in the upstream region of SUC2 gene, 4 expression plasmids YFD1110#1, YFD110#9, YFD110#17 and YFD110#11 were constructed. They contained different hybrid promoters for transciption of SUC2 gene. After transforming them together with two control plasmids YFD26#1 . YFD25 into yeast S. cerevisiae Y33 respectively, the transfonmants were grown in the repression or derepression media and the invertase produced by each transformants were analyzed by colormetry and gel electrophoresis. The results were as followis: ( 1 ) UASSUC2 and UASADH2 in the hybrid plasmid YFD11O#1 worked synergically under derepression condition. Under repression condition, Y33 / YFD110#1 produced very low level of glycosylation inverbue. (2) Compared with three different derepression media, the medium containing low concentration glucose gave higher derepression effeciency of glycosylated invertase than the media containing glycerol and ethanol.