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在酶中,从稳定状态活动测量结果中推断出的分子内部和分子间电子转移率
Sébastien Dementin1, Bénédicte Burlat, Vincent Fourmond
1Laboratoire de Bioénergétique et Ingénierie des Protéines, CNRS UPR 9036, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Journal of the American Chemical Society
|May 28, 2011
概括
呼吸酶中的电子转移速率对铁硫 (FeS) 集群协调有着惊人的敏感性. 这项研究量化了FeS-to-FeS电子传输速率,揭示了超越距离和潜力的关键因素.
科学领域:
- 生物化学 生物化学
- 生物能源学 生物能源学
- 酶学 是一种酶学.
背景情况:
- 通过铁硫 (FeS) 集群长距离的电子转移对于像化酶和线粒体复合体这样的呼吸酶至关重要.
- 尽管假设快速转移,但这些酶内FeS-to-FeS电子转移速率的直接测量一直缺乏.
- 了解这些速率对于阐明酶机制和生物能量过程至关重要.
研究的目的:
- 开发和应用一种原始的策略,以量化测量呼吸酶中的FeS-to-FeS电子转移速率.
- 调查影响电子传输速率的因素,特别是FeS集群性质和协调的作用.
主要方法:
- 对NiFe酶应用了一种新的策略,涉及对稳定状态活性变化的定量解释.
- 修改了FeS集群的性质,将活性部位连接到还氧化伙伴和/或还氧化伙伴本身.
- 从广泛的数据集中推导出分子内部和分子间电子转移速率.
主要成果:
- 通过使用新的策略,成功推断出FeS-to-FeS电子转移率.
- 观察到突变诱导的电子转移速率变化并不能通过中心间距离或还原潜力的变化来解释.
- 证明了FeS-to-FeS速率常数对FeS中心的性质和协调环境的极度敏感性.
结论:
- 建立了一种直接测量呼吸酶FeS-FeS电子转移速率的方法.
- 结论:FeS集群协调和内在性质显著影响电子转移动力学,挑战了以前的假设.
- 强调FeS集群的局部环境在决定电子传输效率方面的重要性.
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