Mapping solvation dynamics at the function site of flavodoxin in three redox states.
Mapping solvation dynamics at the function site of flavodoxin in three redox states.
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DOI：
10.1021/ja1050154
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发表时间：
2010-09-15
影响因子：
15
通讯作者：
Zhong, Dongping
中科院分区：
文献类型：
--
作者：
Chang, Chih-Wei;He, Ting-Fang;Guo, Lijun;Stevens, Jeffrey A.;Li, Tanping;Wang, Lijuan;Zhong, Dongping
黄素蛋白是一类独特的氧化还原辅酶，其功能位点的动态溶剂化作用是研究其电子传递性质的关键。在这里，我们报告了三种氧化还原状态下全黄氧还蛋白功能位点溶剂化和脱辅基黄氧还蛋白结合位点溶剂化的完整表征。使用内在黄素辅因子和色氨酸残基作为具有两个位点特异性突变的局部光学探针，我们在三种状态的功能位点和辅因子的相关识别位点处观察到不同的超快溶剂化动力学，范围从几皮秒到数百皮秒。1-2.6 ps的初始超快运动反映了浅的溶剂暴露功能位点周围的局部水网络弛豫。在20-40 ps的第二次弛豫是由耦合的局域水-蛋白质涨落引起的。第三种动力学是在几百皮秒的范围内，来自功能位点辅因子侧翼的松散环的内在波动。这些溶剂化动力学与不同的振幅以及相关的氧化还原状态从氧化形式，更刚性的半醌和更松散的氢醌。局部蛋白质构象可塑性和水网络灵活性的氧化还原控制的观察是显着的，这种密切的关系是必不可少的蛋白质间电子转移的生物功能。
Flavoproteins are unique redox coenzymes and the dynamic solvation at their function sites is critical to the understanding of their electron-transfer properties. Here, we report our complete characterization of the function-site solvation of holoflavodoxin in three redox states and of the binding-site solvation of apoflavodoxin. Using intrinsic flavin cofactor and tryptophan residue as the local optical probes with two site-specific mutations, we observed distinct ultrafast solvation dynamics at the function site in the three states and at the related recognition site of the cofactor, ranging from a few to hundreds of picoseconds. The initial ultrafast motion in 1–2.6 ps reflects the local water-network relaxation around the shallow, solvent-exposed function site. The second relaxation in 20–40 ps results from the coupled local water-protein fluctuation. The third dynamics in hundreds of picoseconds is from the intrinsic fluctuation of the loose loops flanking the cofactor at the function site. These solvation dynamics with different amplitudes well correlate with the redox states from the oxidized form, to the more rigid semiquinone and to the much looser hydroquinone. This observation of the redox control of local protein conformation plasticity and water network flexibility is significant and such an intimate relationship is essential to the biological function of interprotein electron transfer.
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影响因子：
64.8
作者：
通讯作者：
--
影响因子：
15
作者：
Kao, Ya-Ting;Tan, Chuang;Zhong, Dongping
通讯作者：
Zhong, Dongping
影响因子：
15
作者：
Kao, Ya-Ting;Saxena, Chaitanya;He, Ting-Fang;Guo, Lijun;Wang, Lijuan;Sancar, Aziz;Zhong, Dongping
通讯作者：
Zhong, Dongping
影响因子：
4.4
作者：
MARONCELLI, M;FLEMING, GR
通讯作者：
FLEMING, GR
DOI：
10.1073/pnas.171168898
发表时间：
2001-08-14
影响因子：
11.1
作者：
Hall, DA;Kooi, CWV;Matthews, RG
通讯作者：
Matthews, RG