大肠杆菌N~α-乙酰基转移酶RimI对人胸腺素α原N末端乙酰化修饰的影响  

Effect of N~α-Terminal Acetyltransferase RimI on Human Prothymosin α Acetylation Expressed in Escherichia coli

作　　者：孙鹏[1] 巩新[1] 唱韶红[1] 马清钧[1] 吴军[1] 刘波[1] 

机构地区：[1]军事医学科学院生物工程研究所,北京100071

出　　处：《生物技术通讯》2011年第3期339-343,共5页Letters in Biotechnology

基　　金：国家自然科学基金(30870050);北京市自然科学基金(5102037)

摘　　要：目的:研究大肠杆菌Nα-乙酰基转移酶RimI对人胸腺素α原(ProTα)N末端乙酰化修饰的影响。方法:在大肠杆菌中共表达ProTα与大肠杆菌Nα-乙酰基转移酶RimI,同时设置只表达ProTα的对照菌,分别提取纯化ProTα,利用HPLC检测其发生乙酰化修饰的程度。结果:ProTα的乙酰化修饰发生在翻译后水平,有无RimI的过表达、诱导时间的长短以及这两个因素之间的交叉效应均对ProTα的乙酰化程度有影响,其F值分别为53.8、89.22及16.28,P值均小于0.0001;无论有无RimI过表达,乙酰化的ProTα所占比例在诱导6 h后逐渐升高(P<0.0001);在过表达Ri-mI的菌株中,乙酰化的ProTα在诱导12 h后占37.4%,而在无RimI过表达的菌株中占64.3%;RimI对ProTα乙酰化的抑制作用从诱导6 h后开始显现(P=0.0007)。结论:在大肠杆菌中,过量的Nα-乙酰基转移酶RimI可抑制人胸腺素α原的乙酰化修饰。Objective：To investigate the effect of RimI,one of the Nα-terminal acetyltransferases of E.coli,on human prothymosin α（ProTα） acetylation.Methods：The human ProTα and Nα-terminal acetyltransferase RimI were co-expressed in E.coli DH5α.To observe the level of N-terminal acetylation on human ProTα,ProTα was purified and detected by HPLC.Results：The ProTα was post-translational acetylated.Over-expression of RimI,long term induction and the cross-effect could affect the level of N-terminal acetylation of ProTα（P0.0001）.The increasing N-terminal acetylated ProTα could be observed after inducing 6 h,whether RimI was over-expressed or not（P0.0001）.There were 37.4% N-terminal acetylated ProTα in the presence of overdose RimI,64.3% N-terminal acetylated ProTα without of overdose RimI after inducing 12 h,and we could observe the inhibition after inducing 6 h（P=0.0007）.Conclusion：The N-terminal acetylation of ProTα was inhibited when over-expressed Nα-terminal acetyltransferase RimI.

关 键 词：N末端乙酰化修饰 Nα-乙酰基转移酶RimI 人胸腺素α原 大肠杆菌 

分 类 号：Q78[生物学—分子生物学] Q555.3