Catalysis-Enhancement via Rotary Fluctuation of F1-ATPase
Catalysis-Enhancement via Rotary Fluctuation of F1-ATPase
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DOI：
10.1016/j.bpj.2013.09.050
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发表时间：
2013-11-19
影响因子：
3.4
通讯作者：
Noji, Hiroyuki
中科院分区：
文献类型：
--
作者：
Watanabe, Rikiya;Hayashi, Kumiko;Noji, Hiroyuki
蛋白质构象波动调节酶的催化能力。构象波动的频率可以调节各个反应步骤的催化速率。在本研究中，我们通过在F-1-ATPase（F-1）的转轴上附加不同粘性阻力系数的探针来调制F-1-ATPase（F-1）的旋转波动频率。F-1在旋转步骤之间的单独旋转暂停对应于ATP水解的某个基元反应步骤的等待状态。这使我们能够通过测量旋转暂停的持续时间来研究旋转波动的频率调制对各个反应步骤速率的影响。虽然磷酸盐释放显着减速，ATP结合和水解步骤是不太敏感或不敏感的探针的粘性阻力系数。基于类似Sumi-Marcus理论模型的布朗动力学模拟再现了实验结果，为转动涨落在F-1速率增强中的作用提供了理论框架.
Protein conformational fluctuations modulate the catalytic powers of enzymes. The frequency of conformational fluctuations may modulate the catalytic rate at individual reaction steps. In this study, we modulated the rotary fluctuation frequency of F-1-ATPase (F-1) by attaching probes with different viscous drag coefficients at the rotary shaft of F-1. Individual rotation pauses of F-1 between rotary steps correspond to the waiting state of a certain elementary reaction step of ATP hydrolysis. This allows us to investigate the impact of the frequency modulation of the rotary fluctuation on the rate of the individual reaction steps by measuring the duration of rotation pauses. Although phosphate release was significantly decelerated, the ATP-binding and hydrolysis steps were less sensitive or insensitive to the viscous drag coefficient of the probe. Brownian dynamics simulation based on a model similar to the Sumi-Marcus theory reproduced the experimental results, providing a theoretical framework for the role of rotational fluctuation in F-1 rate enhancement.