文献类型：期刊文献

中文题名：双质粒系统共表达大肠杆菌肉碱脱水酶基因caiB及其辅酶合成基因caiE

英文题名：Coexpression of caiB and caiE with Two Plasmids in E.coli

作者：范立强[1];袁勤生[1];吴祥甫[2]

机构：[1]华东理工大学生物反应器工程国家重点实验室,生物化学研究所,上海200237;[2]中国科学院上海生物化学研究所,上海200031

年份：2002

卷号：34

期号：1

起止页码：104

中文期刊名：生物化学与生物物理学报

收录：CSTPCD;;Scopus;北大核心:【北大核心2000】；CSCD:【CSCD2011_2012】；PubMed;

语种：中文

中文关键词：肉碱;共表达;双质粒系统;相容质粒;不相容质粒;大肠杆菌;肉碱脱水碱;辅酶合成基因

外文关键词：carnitine; coexpression; two plasmids; compatible plasmids; incompatible plasmids

摘要：caiB基因和caiE基因分别编码肉碱脱水酶及其辅因子合成酶 ,两者的共表达可以获得高活性肉碱脱水酶的重组菌。分别用两相容性质粒和不相容质粒共表达肉碱脱水酶及其辅酶合成基因 ,并对两种方法进行了比较。经IPTG诱导 ,相容性双质粒系统中两基因表达量分别占菌体总蛋白质的 17%和 10 % ;不相容性双质粒系统中两基因表达量分别占菌体总蛋白质的 39%和 2 0 %。共转化菌的酶活力比pET2 8caiB单质粒转化菌均提高 2 .3倍左右。两种双质粒转化系统相似 。
Recombinant bacteria exhibiting high enzymatic activities were obtained by cloning and coexpression of both caiB gene and caiE gene in the host of E.coli Bl21(DE3), which encode carnitine dehydratase and a protein related to the synthesis of cofactor for carnitine dehydratase, respectively. In order to coexpress these two genes, compatible and incompatible two plasmids system were used, the difference between them was also studided. After induction with IPTG, both caiB and caiE genes were coexpressed in both compatible two plasmids system and incompatible two plasmids system. In the former system, the expressed products accounted for 17% and 10% of the total proteins in the host; in the later system, the proportion was 39% and 20%, receptively. The activity of carnitine dehydratase in E.coli Bl21(DE3) with either coexpression system is about 2.3 times than that in E.coli Bl21(DE3) with only pET28-caiB. The plasmids stabilities in these two systems were the same, all needed the help of antibiotic selective pressure.