期刊论文

Liu, J.

中文

生物工程学报

1000-3061

2010

26

9

1302-1308

10.13345/j.cjb.2010.09.009

湖北省教育厅重点项目（No.D200718002）资助~~；

本校为第一且通讯机构

利用重组大肠杆菌表达丝氨酸羟甲基转移酶（SHMT）和色氨酸酶（TPase）,并利用双酶法合成L-色氨酸。采用PCR从大肠杆菌K12基因组中扩增上述两种酶的基因,利用pET-28a载体,构建单表达重组质粒pET-SHMT、pET-TPase和共表达重组质粒pET-ST。将上述3种重组质粒转入大肠杆菌BL21（DE3）进行表达。SDS-PAGE结果表明,单表达基因工程菌BL21（DE3）/pET-SHMT和BL21（DE3）/pET-TPase分别在47kDa（SHMT）和50kDa（TPase）处有蛋白表达带;共表达基因工程菌BL21（DE3）/pET-ST在上述两处均有蛋白表达带。与宿主菌相比,单表达SHMT基因工程菌产酶活性提高了6.4倍;单表达TPase基因工程菌产酶活性提高了8.4倍;共...

Hydroxymethyltransferase (SHMT) and tryptophanase (TPase) are key enzymes in biosynthesis of L-tryptophan. We constructed three recombinant plasmids, including pET-SHMT, pET-TPase, and pET-ST for over-expression or co-expression of SHMT and TPase in Escherichia coli BL21 (DE3). The SDS-PAGE analysis showed that the recombinant proteins of 47 kDa and 50 kDa were expressed of pET-SHMT and pET-TPase, respectively. As compared to the host stain, the enzyme activity of SHMT and TPase was increased by 6.4 and 8.4 folds, respectively. Co-expression of...