胸腺素α1的乙酰化修饰不依赖于乙酰转移酶RimL  

The Acetylation of Thymosin α1 is Independent on RimL in Escherichia coli

作　　者：张旭[1,2] 苗林[2] 方宏清[2] 戴红梅[2] 李树龙[2] 沈明山[1] 陈惠鹏[2] 

机构地区：[1]厦门大学生命科学学院,福建厦门361005 [2]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》2009年第1期15-18,共4页Letters in Biotechnology

摘　　要：目的:考察大肠杆菌乙酰转移酶RimL对胸腺素α1(Tα1)乙酰化修饰的影响。方法:构建含500bp同源臂的卡那抗性基因打靶片段,利用Red同源重组系统,使大肠杆菌BL21(DE3)的rimL基因插入失活,随后导入质粒pCP20去除抗性基因,构建突变菌株rimL-BL21(DE3);将重组质粒pET-Tα1-L12分别转入出发菌株和突变菌株中进行表达,经固定金属离子亲和层析和反向高效液相层析后,将所得纯品进行质谱分析,精确测定相对分子质量。结果:PCR鉴定结果证明成功敲除rimL基因;质谱结果表明,rimL基因敲除菌中所表达的Tα1-L12融合蛋白与出发菌株一样,均有部分乙酰化修饰。结论:Tα1的乙酰化修饰并不依赖于RimL。Objective： To investigate the effect of RimL, a N-terminal acetyhransferase of E.coli, on thymosin α1（Tα1） acetylation. Methods： A kanamycin cassette with two 500 bp long arms homologous to the regions around rimL as the replacement fragment was electroporated into cells, in which the Red recombinant functions was induced. Subsequently, the plasmid pCP20 was transformed to eliminate the kanamycin resistant gene. The plasmid pET-Tα1-L12 was transformed in-to the original and mutant strains respectively. The expressed fusion protein Tα1-L12 was purified by IMAC and RPHPLC. The accurate molecular weight of the fusion protein was measured by Q-TOF-MS. Results： The gene rimL was inactivated by insertion of the replacement fragment successfully. According to the MS results, the fusion protein Tα1-L12 was still partly acetylated when it was expressed in the mutant strains as in the original strains. Conclusion： Tα1 acetylation was independent on RimL.

关 键 词：胸腺素Α1 乙酰化 乙酰转移酶RimL RED重组 

分 类 号：Q78[生物学—分子生物学]