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 investigat...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.展开更多
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）.
文摘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.
