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大型道效应在 bis ((μ-oxo) 二铜酶中的气转移:一个理论研究
Kisoo Park1, Youngshang Pak, Yongho Kim
1Department of Applied Chemistry, Kyung Hee University, 1 Seochun-Dong, Giheung-Gu, Yongin-Si, Gyeonggi-Do 446-701, Korea.
Journal of the American Chemical Society
|January 27, 2012
概括
量子计算在二铜酶模型中准确预测了动态同位素效应,揭示了在C-H键激活过程中显著的道化. 这种道与最小能量路径显著不同,突出了高效的气转移机制.
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:
- 第三类铜酶具有双铜中心,对于使用分子氧激活形C-H键至关重要.
- 二铜酶模型在转移中表现出很大的动态同位素效应 (KIEs),这表明了显著的量子道化.
研究的目的:
- 为了准确地预测KIE和Arrhenius参数用于二铜酶模型,使用变量过渡状态理论.
- 调查多维道在这些系统内的气转移中的作用和效率.
主要方法:
- 采用变量过渡状态理论和量子力学计算来确定最小能量路径 (MEP).
- 采用了70个原子的二氧化铜酶的计算模型,定义了一个204维的潜在能量表面.
- 为233K的异烯联体系统计算了KIEs和Arrhenius参数.
主要成果:
- 在计算值和实验值之间取得了很好的一致性,对于E (a) (H) -E (a) (D),A (H) /A (D) 和KIE (28.1在233K).
- 确定了沿着代表性道通道 (RTP) 的最大能量低于3.3 kcal/mol的0.54 Å的道.
- 证明RTP与MEP有显著的差异,重原子在气道之前移动.
结论:
- 变异过渡状态理论在二铜酶模型中准确地模拟KIEs和Arrhenius参数.
- 量子道在转移中起着非常高效的作用,与经典反应途径不同.
- 这些发现为含铜酶激活C-H键的机制提供了关键的见解.
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