Low operational stability of enzymes in dry organic solvents: changes in the active site might affect catalysis.
Low operational stability of enzymes in dry organic solvents: changes in the active site might affect catalysis.
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DOI：
10.3390/molecules17021870
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发表时间：
2012-02-14
期刊：
影响因子：
--
通讯作者：
Barletta G
中科院分区：
文献类型：
--
作者：
Bansal V;Delgado Y;Legault M;Barletta G
酶在有机溶剂中的催化性能受有机溶剂的影响，使其在合成中的应用前景黯然失色。此外，最近的研究表明，一种酶在长时间暴露在有机介质中后，其初始活性会显著降低。旨在理解这最后一个缺陷的研究产生了不清楚的结果。在本工作中，我们决定使用电子顺磁共振波谱(EPR)来研究丝氨酸蛋白酶枯草杆菌Carlsberg在四种不同的有机溶剂中暴露96h期间，活性中心自旋标记(氮氧自由基)的运动。我们的EPR数据显示了一个典型的双组分光谱，它由各向异性和各向同性信号的比率来量化。各向同性成分与可移动的氮氧化物自由基有关，在长时间暴露于研究中使用的所有溶剂中会增加。其中，1，4-二恶烷的增幅最大，达43%。基于这些和以前的研究，我们认为酶长时间暴露在这些溶剂中会引发一系列事件，这些事件可能会诱导底物采用不同的结合构象。这是迄今报道的第一个关于酶在有机溶剂中长时间暴露过程中活性部位自旋标记运动的EPR研究。
The potential of enzyme catalysis in organic solvents for synthetic applications has been overshadowed by the fact that their catalytic properties are affected by organic solvents. In addition, it has recently been shown that an enzyme’s initial activity diminishes considerably after prolonged exposure to organic media. Studies geared towards understanding this last drawback have yielded unclear results. In the present work we decided to use electron paramagnetic resonance spectroscopy (EPR) to study the motion of an active site spin label (a nitroxide free radical) during 96 h of exposure of the serine protease subtilisin Carlsberg to four different organic solvents. Our EPR data shows a typical two component spectra that was quantified by the ratio of the anisotropic and isotropic signals. The isotropic component, associated with a mobile nitroxide free radical, increases during prolonged exposure to all solvents used in the study. The maximum increase (of 43%) was observed in 1,4-dioxane. Based on these and previous studies we suggest that prolonged exposure of the enzyme to these solvents provokes a cascade of events that could induce substrates to adopt different binding conformations. This is the first EPR study of the motion of an active-site spin label during prolonged exposure of an enzyme to organic solvents ever reported.
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影响因子：
3.5
作者：
Castillo B;Bansal V;Ganesan A;Halling P;Secundo F;Ferrer A;Griebenow K;Barletta G
通讯作者：
Barletta G
影响因子：
2.9
作者：
Columbus, L;Hubbell, WL
通讯作者：
Hubbell, WL
影响因子：
3.8
作者：
Fasoli, Ezio;Ferrer, Amaris;Barletta, Gabriel L.
通讯作者：
Barletta, Gabriel L.
影响因子：
15
作者：
Lee, T;Jones, JB
通讯作者：
Jones, JB
影响因子：
--
作者：
Castillo, B;Pacheco, Y;Barletta, G
通讯作者：
Barletta, G