构建高表达酪氨酸酚裂解酶重组大肠杆菌合成左旋多巴

Construction of Tyrosine Phenol Lyase Over-Expression Recombinant E. coli for the Biosynthesis of Levodopa

以PCR技术扩增得到弗氏柠檬酸细菌ATCC8090中酪氨酸酚裂解酶的结构基因tpl,与表达载体pQE30连接后构建质粒pQTPL,并转化到E.coliM15中进行表达,在加入0.2mmol/L的IPTG、18℃表达14h的诱导条件下,酪氨酸酚裂解酶比活为208u/mg。50ml摇瓶中E.coliM15(pQTPL)合成左旋多巴产量达55g/L。

The structural gene tpl encoding tyrosine phenol lyase was amplified by PCR using Citrobacterfreundii ATCC 8090 chromosomal DNA as template, then the obtained DNA fragment was ligated into an expression vector pQE30 to construct a new recombinant plasmid pQTPL, which was transformed into E. coli M 15 for expression. The recombinant E. coli M15 （pQTPL） could express tyrosine phenol lyase under the induction conditions at 18℃ with 0.2mmol/L IPTG for 14h, the specific activity of tyrosine phenol lyase was 208u/mg. 55g/L of levodopa was obtained in 50ml shake flask by E. coli M 15 （pQTPL）.