Water dependent properties of cutinase in nonaqueous solvents: a computational study of enantioselectivity.
Water dependent properties of cutinase in nonaqueous solvents: a computational study of enantioselectivity.
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DOI：
10.1529/biophysj.105.063297
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发表时间：
2005-08
影响因子：
3.4
通讯作者：
N. Micaêlo;V. Teixeira;A. Baptista;C. M. Soares
中科院分区：
文献类型：
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作者：
N. Micaêlo;V. Teixeira;A. Baptista;C. M. Soares
已知酶在非水溶剂中的催化性质取决于溶剂的性质。在这里，我们提出了一个分子模拟研究的酶角质酶在己烷中的不同水合条件下的对映选择性。以前的模拟研究表明，对于己烷中的这种模型酶，结构和动力学性质受到与蛋白质相关的水量的影响，更类似于含水量为5-10%的水模拟。采用四面体中间体（TI）模型的自由能计算方法，研究了水化程度对（R，S）-1-苯基乙醇和（R，S）-2-苯基-1-丙醇酶拆分的影响.与此模型系统，我们表明，酶的对映体选择性的性质是在有机介质中存在的水量的控制下。最大的对映体选择性达到10%的水含量。在不同的水含量的催化组氨酸对TI的稳定作用进行了评价，并显示出相关性。介质中存在的水的量和酶的结构，动力学和热力学性质之间的相关性进行检查，以及活性位点的判别力。
The catalytic properties of enzymes in nonaqueous solvents are known to be dependent on the nature of the solvent. Here we present a molecular modeling study of the enantioselective properties of the enzyme cutinase in hexane under varying hydration conditions. Previous simulation studies have shown that for this model enzyme in hexane, the structural and dynamical properties are affected by the amount of water associated with the protein, being more similar to the aqueous simulation at 5-10% of water content. The implications of the hydration levels on the enzyme resolution of (R,S)-1-phenylethanol and (R,S)-2-phenyl-1-propanol are investigated using free energy calculations of the tetrahedral intermediate (TI) model. With this model system we show that the enzyme enantioselective properties are under the control of the amount of water present in the organic media. Maximum enantioselectivity is achieved at 10% water content. The stabilizing effects of the catalytic histidine on the TI are evaluated at different water contents and shown to be correlated. The correlation between the amount of water present in the media and the structural, dynamical, and thermodynamic properties of the enzyme are examined as well as the active site discriminative power.