The origin and impact of bound water around intrinsically disordered proteins
The origin and impact of bound water around intrinsically disordered proteins
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本质无序蛋白质周围结合水的起源和影响
DOI：
10.1016/j.bpj.2022.01.011
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发表时间：
2022
影响因子：
3.4
通讯作者：
Leitner, David M.
中科院分区：
文献类型：
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作者：
Reid, Korey M.;Singh, Abhishek K.;Bikash, Chowdhury R.;Wei, Jessica;Tal-Gan, Yftah;Vinh, Nguyen Q.;Leitner, David M.
蛋白质和水在广泛的时间范围内动态耦合。由于蛋白质在蛋白质功能中的核心作用，蛋白质-水动力学和热力学已经被广泛地研究，其中与结构特征相对应。然而，控制固有无序蛋白质(IDP)-水动力学的性质尚不清楚。我们报道了一组电荷含量不同的IDPs以及大小相似的结构蛋白的兆赫到太赫兹介电光谱和分子动力学模拟的结果。与大小相似的结构蛋白周围的水相比，IDPs周围的水合水表现出更多的异质旋转和平移动力学，与结构蛋白相比，IDPs周围的单个残基，无论是带电的还是中性的，平均产生更有限的动力学。平均而言，较慢的水动力学被发现是由于第一水化层中过多的紧密结合水引起的，这与接触更多的带电基团有关。与IDPs结合得越紧密的水与实验发现的较小的水合壳相关，并影响与蛋白质-水相互作用相关的熵，我们基于介电测量和模拟估计其贡献。通过介电测量和模拟研究了水-IDP在太赫兹频率下的动态耦合特性。
Proteins and water couple dynamically over a wide range of time scales. Motivated by their central role in protein function, protein-water dynamics and thermodynamics have been extensively studied for structured proteins, where correspondence to structural features has been made. However, properties controlling intrinsically disordered protein (IDP)-water dynamics are not yet known. We report results of megahertz-to-terahertz dielectric spectroscopy and molecular dynamics simulations of a group of IDPs with varying charge content along with structured proteins of similar size. Hydration water around IDPs is found to exhibit more heterogeneous rotational and translational dynamics compared with water around structured proteins of similar size, yielding on average more restricted dynamics around individual residues of IDPs, charged or neutral, compared with structured proteins. The on-average slower water dynamics is found to arise from excess tightly bound water in the first hydration layer, which is related to greater exposure to charged groups. The more tightly bound water to IDPs correlates with the smaller hydration shell found experimentally, and affects entropy associated with protein-water interactions, the contribution of which we estimate based on the dielectric measurements and simulations. Water-IDP dynamic coupling at terahertz frequencies is characterized by the dielectric measurements and simulations.