量子力学/分子力学研究了酶的Baeyer-Villiger反应的机制
Iakov Polyak1, Manfred T Reetz, Walter Thiel
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
Journal of the American Chemical Society
|January 14, 2012
概括
这项研究使用量子力学/分子力学来研究环素单氧化酶 (CHMO). QM/MM计算揭示了关键反应步骤以及Arg-329和NADP的作用在CHMO中.
科学领域:
- 生物化学 生物化学
- 计算化学计算化学
- 酶学 是一种酶学.
背景情况:
- 环松单氧化酶 (CHMO) 催化了贝耶-维利格反应.
- 了解酶机制对于酶工程和药物设计至关重要.
研究的目的:
- 使用量子力学/分子力学 (QM/MM) 组合方法阐明CHMO的反应机制.
- 研究关键残留物和辅助因子在CHMO的催化效率和酶选择性中的作用.
主要方法:
- 使用密度函数理论 (B3LYP/TZVP) 的QM/MM几何优化和反应路径计算.
- QM/MM分子动力学模拟和在半实证OM3/CHARMM水平上的自由能量计算.
- 量子力学区域的气相再优化.
主要成果:
- 酶-反应物复合体具有由Arg-329和NADP(+) 稳定的一种脱的C4a-氧黄.
- 反应通过一种阴离子克里奇介质进行,初始添加的能量障碍为9kcal/mol,乳形成的能量障碍为7kcal/mol.
- -329和NADP ((+) 对CHMO的催化效率至关重要.
- QM/MM计算成功地重现了实验观察到的 (S) -enantioselectivity对4-甲基环松氧化.
结论:
- 该QM/MM研究提供了关于CHMO催化Baeyer-Villiger反应机制的详细见解.
- 鉴定的过渡状态和中间体突出显示了酶微环境的重要性.
- 这些发现合理化了CHMO反应中观察到的基质特异性酶选择性.
相关概念视频
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
Baeyer–Villiger oxidation converts aldehydes to carboxylic acids and ketones to esters. The reaction uses peroxy acids or peracids and is often catalyzed by acid. The reaction is named after its pioneers, Adolf von Baeyer and Victor Villiger. The reaction is achieved by a wide range of peracids such as m-chloroperoxybenzoic acid (mCPBA), perbenzoic acid (C6H5COOOH), peracetic acid (CH3COOOH), hydrogen peroxide (H2O2), and tert-butyl hydroperoxide (t-BuOOH).
The carbonyl center is activated by...
The carbonyl center is activated by...
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Chemical reactions often occur in a stepwise fashion, involving two or more distinct reactions taking place in a sequence. A balanced equation indicates the reacting species and the product species, but it reveals no details about how the reaction occurs at the molecular level. The reaction mechanism (or reaction path) provides details regarding the precise, step-by-step process by which a reaction occurs.
For instance, the decomposition of ozone appears to follow a mechanism with two steps:
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