Functional characterization of a thermostable methionine adenosyltransferase from Thermus thermophilus HB27  

作　　者：Yanhui Liu Biqiang Chen Zheng Wang Luo Liu Tianwei Tan 

机构地区：[1]Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing 100029, China

出　　处：《Frontiers of Chemical Science and Engineering》2016年第2期238-244,共7页化学科学与工程前沿（英文版）

基　　金：This work was financially supported by the National 973 Basic Research Program of China （2014CB745100）, National Natural Science Foundation of China （Grant Nos. 21376024 and 21390202）.

摘　　要：MATTt （a thermostable methionine adenosyl- transferase from Thermus thermophilus HB27） was over- expressed in Escherchia coli and purified using Ni-NTA affinity column. The enzymatic activity of MATTt was investigated in a temperature range from 30 ℃ to 90 ℃, showing that MATTt exhibited a high enzymatic activity and good thermostability at 80 ℃. Circular dichroism spectra reveals that MATTt contains high portion of β- sheet structures contributing to the thermostability of MATTt. The kinetic parameter, Km is 4.19 mmoFL and 1.2 mmol/L for ATP and methionine, respectively. MATTt exhibits the highest enzymatic activity at pH 8. Cobalt （Co^2＋） and zinc ion （Zn^2＋） enhances remarkably the activity of MATTt compared to the magnesium ion （Mg^2＋）. All these results indicated that the thermostable MATTt has great potential for industry applications.MATTt （a thermostable methionine adenosyl- transferase from Thermus thermophilus HB27） was over- expressed in Escherchia coli and purified using Ni-NTA affinity column. The enzymatic activity of MATTt was investigated in a temperature range from 30 ℃ to 90 ℃, showing that MATTt exhibited a high enzymatic activity and good thermostability at 80 ℃. Circular dichroism spectra reveals that MATTt contains high portion of β- sheet structures contributing to the thermostability of MATTt. The kinetic parameter, Km is 4.19 mmoFL and 1.2 mmol/L for ATP and methionine, respectively. MATTt exhibits the highest enzymatic activity at pH 8. Cobalt （Co^2＋） and zinc ion （Zn^2＋） enhances remarkably the activity of MATTt compared to the magnesium ion （Mg^2＋）. All these results indicated that the thermostable MATTt has great potential for industry applications.

关 键 词：ion-preference methionine adenosyltransfer-ase secondary structure thermostability Thermus thermo-philus 

分 类 号：Q93-335[生物学—微生物学] S831.5[农业科学—畜牧学]