双控表达载体系统的构建及其在基因表达方面的应用（英文）

Strict Regulation of Gene Expression Utilizing a Dual-control Gene Expression Vector System

可严格调控性是体现原核表达载体优越性的重要指标。构建了一种双控双调节原核表达载体系统,用双载体控制调节目的基因的表达,即SP6启动子(promoter)+乳糖(lac)调节基因表达系统和araB启动子(promoter)+ara C调节基因表达系统,分别由乳糖类似物IPTG和阿拉伯糖(L-arabinose)诱导目的基因的表达。该系统由2个表达载体共同完成目的基因的表达。pE SP-1为主表达载体,即目的基因克隆到此表达载体上,由SP6启动子(promoter)+乳糖(lac)调节基因调控;pA RA-SP6为辅助表达载体,该载体通过SP6 RNA聚合酶的表达来控制调节主表达载体的启动子(SP6),由araB启动子(promoter)+ara C调节基因调控。实验结果显示该双控双调节表达载体系统控制严格,并且表达蛋白的量具有可调控性。

Attempts to suppress the expression of genes from high copy vector plasmids often are unable to prevent residual or ＂ leaky＂ protein production. A dual vector system（ DCVS） was generated for the expression of protein in E.coli host. T7 promoter of pE T-11 a was replaced with Sp6 promoter to attenuate the transcription activity; ＂ Couple locks＂（ lac operator and ara C regulation protein） shut off target gene expression; DCVS could be used to express a great many genes in a wide range of hosts that cannot themselves supply SP6 RNA polymerase. DCVS facilitates the strict regulation of target gene being harmful or lethal to the host. In addition,it was found that protein expression using this system was regulated in a dose-dependent manner,allowing a range of protein concentrations to be achieved.