表达磷酸转移酶工程菌整细胞催化肌苷5′-位磷酸化的工艺条件研究

Study on the Reaction Conditions of the Enzymatic 5′-Phosphorylation of Inosine using Whole Cells of Engineered E. coli with Expression of Phosphotransferase

摘要:

本文利用构建的表达产气肠杆菌酸性磷酸转移酶phoc基因的E. coli BL21，对其整细胞催化肌苷5′-位磷酸化的工艺条件进行了研究。研究结果表明在整细胞PHOC酶活、肌苷和焦磷酸浓度分别为45 U、100 mM和120 mM时，反应6 h肌苷转化率达到63.36%。为进一步提高转化率，研究了3种表面活性剂对整细胞肌苷转化率的影响，在Trion-x-100浓度为0.3%时，肌苷转化率提高到74.59%。该研究为酶催化肌苷5′-位磷酸化的工业化进程提供了技术支持。

Abstract:

In this paper, the enzymatic phosphorylation of inosine in the 5′-position to produce inosine-5′-monophosphate (5′-IMP) with whole cells was studied, using the engineered E. coli BL21 with the expression of acid phosphotransferase (PHOC) phoc gene originated E.aerogenes IAM 1183. A maximum conversion rate of 63.36% was obtained after 6 h of enzymatic reaction at 30 oC in 100 mM inosine and 120 mM pyrophosphate (ppi) with PhOC activity of 45 U in a 150 mL reaction system. To further improve the conversion rate, the effects of three surfactants on the conversion rate were studied, and the conversion rate of inosine was increased to 74.59% at the addition of 0.3% Trion-x-100. This study provided basic data for the industrial application of the PHOC in production of 5′-IMP.