文献类型：期刊文献

英文题名：Enzymatic synthesis of nucleosides by nucleoside phosphorylase co-expressed in Escherichia coli

作者：Ding, Qing-bao[1];Ou, Ling[1];Wei, Dong-zhi[1];Wei, Xiao-kun[2];Xu, Yan-mei[2];Zhang, Chun-yan[2]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Scibest Biotechnol Co Ltd, Shanghai 200235, Peoples R China

年份：2010

卷号：11

期号：11

起止页码：880

外文期刊名：JOURNAL OF ZHEJIANG UNIVERSITY-SCIENCE B

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000285157500009)】；

语种：英文

外文关键词：Nucleoside phosphorylase; Lactose; Enzymatic synthesis

摘要：Nucleoside phosphorylase is an important enzyme involved in the biosynthesis of nucleosides. In this study, purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase were co-expressed in Escherichia coli and the intact cells were used as a catalyst for the biosynthesis of nucleosides. For protein induction, lactose was used in place of isopropyl beta-D-1-thiogalactopyranoside (IPTG). When the concentration of lactose was above 0.5 mmol/L, the ability to induce protein expression was similar to that of IPTG. We determined that the reaction conditions of four bacterial strains co-expressing these genes (TUD, TAD, DUD, and DAD) were similar for the biosyntheses of 2,6-diaminopurine nucleoside and 2,6-diaminopurine deoxynucleoside. When the substrate concentration was 30 mmol/L and 0.5% of the recombinant bacterial cell volume was used as the catalyst (pH 7.5), a greater than 90% conversion yield was reached after a 2-h incubation at 50 degrees C. In addition, several other nucleosides and nucleoside derivatives were efficiently synthesized using bacterial strains co-expressing these recombinant enzymes.