Protein conformational dynamics probed by single-molecule electron transfer
Protein conformational dynamics probed by single-molecule electron transfer
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DOI：
10.1126/science.1086911
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发表时间：
2003-10-10
期刊：
影响因子：
56.9
通讯作者：
Xie, XS
中科院分区：
文献类型：
--
作者：
Yang, H;Luo, GB;Xie, XS
电子转移被用作单个蛋白质分子中埃级结构变化的探针。在黄素还原酶中，黄素的荧光通过光诱导电子转移被附近的酪氨酸残基猝灭。通过逐光子探测单个黄素的荧光寿命，我们能够观察到黄素-酪氨酸距离随时间的变化。然后，我们可以确定黄素和酪氨酸之间的平均力的潜力，和相关性分析揭示了构象波动在多个时间尺度，从数百微秒到秒。这一现象表明，存在多个相互转换的构象有关的波动催化反应性。
Electron transfer is used as a probe for angstrom-scale structural changes in single protein molecules. In a flavin reductase, the fluorescence of flavin is quenched by a nearby tyrosine residue by means of photo-induced electron transfer. By probing the fluorescence lifetime of the single flavin on a photon-by-photon basis, we were able to observe the variation of flavin-tyrosine distance over time. We could then determine the potential of mean force between the flavin and the tyrosine, and a correlation analysis revealed conformational fluctuation at multiple time scales spanning from hundreds of microseconds to seconds. This phenomenon suggests the existence of multiple interconverting conformers related to the fluctuating catalytic reactivity.