Abstract:

Acid phosphotransferase of E.aerogenes IAM1183 is of high potential for industrial application due to high regiospecificity of the nucleoside phosphorylating activity to the C-5′-position.In this study, the phoC gene was isolated and sequenced from E.aerogenes IAM1183 and fused with the MBP (maltose binding protein) gene to construct expressing vector pMKL-c2x-phoC named as pcphoC.The pcphoC was transferred into different host strains for the expression of the MBP-Pho fusion protein.It was found that the transformed E.coli TB1I (pcphoC) exhibited the highest phosphotransferase activity.The hydrolysis activity was lower than that of the original strain.And the optimum pH was 6.7 in the vicinity of neutral.

Key words:

产气肠杆菌, 酸性磷酸酶, 克隆, 5′-肌苷酸

摘要：

产气肠杆菌(E.aerogenes IAM1183)的酸性磷酸酶，具有特异转移磷酸基团到核苷5′-位的功能，是极具应用价值的酶。本研究以产气肠杆菌(E.aerogenes IAM1183)的酸性磷酸酶(PhoC)为研究对象，采用基因工程手段，克隆了phoC基因，构建成酸性磷酸酶(PhoC)与麦芽糖结合蛋白(MBP)的融合表达载体pMKL-c2x-phoC，把其转化到不同的宿主，进行催化研究。结果发现构建成的基因工程菌具有高于原始菌催化5′-IMP生成的能力、水解5′-IMP的活性降低、酶促反应的最适pH值近中性等特点。

关键词:

产气肠杆菌, 酸性磷酸酶, 克隆, 5′-肌苷酸