呼吸综合体I的NADH/FMN位点中的质子合电子转移的能量和动力学
Patricia Saura1, Ville R I Kaila1
1Department of Chemistry , Technical University of Munich (TUM) , Lichtenbergstrasse 4 , Garching D-85747 , Germany.
Journal of the American Chemical Society
|March 16, 2019
概括
复合体I通过质子合电子转移 (PCET) 反应启动有氧呼吸. 这项研究揭示了协调的原子和电子转移机制,解释了复杂I中的辅因子相互作用和NAD+结合.
科学领域:
- 生物化学
- 分子生物学
- 生物能源
背景情况:
- 复合物I是有氧呼吸链中的关键酶,启动电子转移和质子.
- 复合I中的NADH和FMN辅因子之间的质子合电子转移 (PCET) 的精确机制仍然不完全理解.
研究的目的:
- 阐明复合I中NADH驱动的PCET反应的能量和动力学.
- 在复合体I中提出启动电子转移的机制模型.
主要方法:
- 大规模密度函数理论 (DFT) 的计算.
- 量子/经典模型与原子分子动力学模拟相结合.
主要成果:
- NADH驱动的PCET反应涉及尼古丁胺氨基二核酸 (NADH) 和黄单核酸 (FMN) 之间的合原子转移与电子转移 (eT).
- 在细菌复合体I中减少N1a FeS中心增强了氧化NAD+结合,可能防止反应性氧物种的形成.
- 将质子转移到保存的谷氨酸残留物有助于随后的电子转移,并调节NADH结合.
结论:
- 在复杂I中提出了NADH驱动的PCET反应的详细机制模型.
- 这些发现揭示了复杂的电子和质子转移途径.
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