Pressure-enhanced activity and stability of a hyperthermophilic protease from a deep-sea methanogen
Pressure-enhanced activity and stability of a hyperthermophilic protease from a deep-sea methanogen
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DOI：
10.1128/aem.63.10.3985-3991.1997
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发表时间：
1997-10-01
影响因子：
4.4
通讯作者：
Clark, DS
中科院分区：
文献类型：
--
作者：
Michels, PC;Clark, DS
我们描述了一种来自jannaschii甲烷球菌（一种极嗜热的深海产甲烷菌）的超嗜热、嗜压蛋白酶的性质。这种酶是第一个从适应高压-高温环境的生物体中分离出来的蛋白酶。部分纯化的酶分子量为29 kDa，底物特异性较窄，多肽底物的pi位点对亮氨酸有强烈的偏好，酶活性在116℃时升高，在130℃时测定，这是报道的酶功能的最高温度之一，此外，酶活性和热稳定性随压力的增加而增加。将压力提高到500 atm时，125℃下的反应速率提高了3.4倍，热稳定性提高了2.7倍。活性位点丝氨酸的自旋标记表明，M. jannaschii蛋白酶的活性位点几何形状与几种中温性蛋白酶没有太大差异；然而，活性位点结构在中等温度下可能是相对刚性的，酶的嗜氧和嗜热行为与先前观察到的m.j annaschii的嗜氧生长一致（J. F. Miller et al., apple）。环绕。中华微生物学杂志，2004(4):539 - 542。
We describe the properties of a hyperthermophilic, barophilic protease from Methanococcus jannaschii, an extremely thermophilic deep-sea methanogen. This enzyme is the first protease to be isolated from an organism adapted to a high-pressure-high-temperature environment. The partially purified enzyme has a molecular mass of 29 kDa and a narrow substrate specificity with strong preference for leucine at the pi site of polypeptide substrates, Enzyme activity increased up to 116 degrees C and was measured up to 130 degrees C, one of the highest temperatures reported for the function of any enzyme, In addition, enzyme activity and thermostability increased with pressure: raising the pressure to 500 atm increased the reaction rate at 125 degrees C 3.4-fold and the thermostability 2.7-fold, Spin labeling of the active-site serine revealed that the active-site geometry of the M. jannaschii protease is not grossly different from that of several mesophilic proteases; however, the active-site structure may be relatively rigid at moderate temperatures, The barophilic and thermophilic behavior of the enzyme is consistent with the barophilic growth of M. jannaschii observed previously (J. F. Miller et al., Appl. Environ. Microbiol. 54:3039-3042, 1988).