Pyrophosphate hydrolysis in the extremely halophilic archaeon Haloarcula japonica is catalyzed by a single enzyme with a broad ionic strength range.
Pyrophosphate hydrolysis in the extremely halophilic archaeon Haloarcula japonica is catalyzed by a single enzyme with a broad ionic strength range.
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极嗜盐古菌 Haloarcula japonica 中的焦磷酸盐水解是由具有宽离子强度范围的单一酶催化的。
DOI：
10.1007/s00792-017-0917-3
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发表时间：
2017
期刊：
影响因子：
2.9
通讯作者：
Y. Sambongi
中科院分区：
文献类型：
--
作者：
S. Wakai;A. Abe;S. Fujii;K. Nakasone;Y. Sambongi
极端嗜盐古菌日本盐弓菌（Haloarcula japonica）的可溶性蛋白质级分在2-4 M NaCl的存在下表现出显著的无机焦磷酸盐（PPi）水解活性（Wakai等人，J Biol Chem 288：29247-29251，2013），其提供高离子强度（2-4）。在该研究中，出乎意料地检测到高得多的PPi水解活性，即使在100-200 mM MgSO 4存在下使用0 M NaCl，在相同的蛋白质级分中提供0.4-0.8的低得多的离子强度。Na+和Mg 2+离子分别需要在高和低离子强度条件下的活性。重组体H。日本焦磷酸酶（HjPPase）在相同的宽离子强度范围内表现出PPi水解活性，表明与这样宽的离子强度范围相关的活性可以归因于单一酶。因此，我们得出结论，HjPPase的宽离子强度范围可能有助于适应Na+和Mg 2+，这是丰富的，但在不稳定的生活环境中的H。日本。
The soluble protein fraction of the extremely halophilic archaeonHaloarcula japonicaexhibits substantial inorganic pyrophosphate (PPi) hydrolysis activity in the presence of 2–4 M NaCl (Wakai et al, J Biol Chem 288:29247–29251, 2013), which provides high ionic strength (2–4). In this study, much higher PPi hydrolysis activity was unexpectedly detected, even with 0 M NaCl in the presence of 100–200 mM MgSO4, providing a much lower ionic strength of 0.4–0.8, in the same protein fraction. Na+and Mg2+ions were required for activity under high and low ionic strength conditions, respectively. A recombinantH. japonicapyrophosphatase (HjPPase) exhibited PPi hydrolysis activity with the same broad ionic strength range, indicating that the activity associated with such a broad ionic strength range could be attributed to a single enzyme. Thus, we concluded that the broad ionic strength range of HjPPase may contribute to adaptation for both Na+and Mg2+which are abundant but variable in the unstable living environments ofH. japonica.