摘要
应用PCR技术从E.coliJM105中扩增出长约1.4Kb的色氨酸酶基因,将其插入高表达载体pET3a的NdeI/BamHI位点,转化E.coliBL21(DE3),构建高产色氨酸酶基因工程菌。SDS-PAGE电泳和薄层扫描表明,工程菌色氨酸酶的表达量占细胞总可溶性蛋白的69.8%。酶活测定结果表明,7株工程菌色氨酸酶的活力比宿主菌均有不同程度的提高,其中WW-11号比宿主菌高16倍。
kb DNA fragment was obtained from E. coli JM 105 by PCR. This fragment was inserted into NdeI/BamHI sites of pET3a. The recombinant plasmids were transformed into host strain E. coli BL 21(DE3). High level expression of tryptophanase genetic engineering strains were constructed. SDS PAGE and TLC were conducted, which proved that tryptophanase was 69.8% of all proteins of engineering strain. The results of enzyme assays showed that the activities of tryptophanase from seven genetic engineering strains were higher than those of host strain to different extent, and the enzyme activity of No.11 was of 16 times as high as that of the host.
出处
《中国药科大学学报》
CAS
CSCD
北大核心
1999年第2期139-142,共4页
Journal of China Pharmaceutical University
关键词
L-色氨酸
色氨酸酶
PCR
克隆
表达
基因工程菌
L Tryptophan
Tryptophanase
PCR
Cloning
Expression
Genetic engineering strain