Wetting of the Protein Active Site Leads to Non-Marcusian Reaction Kinetics
Wetting of the Protein Active Site Leads to Non-Marcusian Reaction Kinetics
复制标题
蛋白质活性位点的润湿导致非马库斯反应动力学
DOI：
10.1021/acs.jpcb.8b10376
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Matyushov, Dmitry V.
中科院分区：
文献类型：
--
作者：
Waskasi, Morteza M.;Martin, Daniel R.;Matyushov, Dmitry V.
酶存在于连续波动的水浴中，显著影响其功能。水不仅形成溶剂化壳，而且渗透到蛋白质内部。响应于改变氧化还原状态而改变蛋白质的活性位点的润湿图案引发活性位点处的高度非线性结构变化和非高斯静电波动。电子转移的自由能表面是高度非抛物型（非Marcusian），如水合铁氧还蛋白的原子分子动力学模拟和与模拟一致的分析模型所示。电子转移的重组能通过一个尖峰，标志着活性位点的湿态和干态的概率相等。受润湿影响的活化热力学导致反应速率与逆温度的非阿耳忒弥斯曲线，通过最大值。
Enzymes exist in continuously fluctuating water bath dramatically affecting their function. Water not only forms the solvation shell but also penetrates into the protein interior. Changing the wetting pattern of the protein’s active site in response to altering redox state initiates a highly nonlinear structural change and non-Gaussian electrostatic fluctuations at the active site. The free-energy surfaces of electron transfer are highly nonparabolic (non-Marcusian), as shown by atomistic molecular dynamics simulations of hydrated ferredoxin protein and by an analytical model in agreement with simulations. The reorganization energy of electron transfer passes through a spike marking equal probabilities of the wet and dry states of the active site. The activation thermodynamics affected by wetting leads to a non-Arrhenius, passing through a maximum, plot for the reaction rate vs the inverse temperature.