Direct Experimental Characterization of Contributions from Self-Motion of Hydrogen and from Interatomic Motion of Heavy Atoms to Protein Anharmonicity
Direct Experimental Characterization of Contributions from Self-Motion of Hydrogen and from Interatomic Motion of Heavy Atoms to Protein Anharmonicity
复制标题
氢自运动和重原子原子间运动对蛋白质非和谐性贡献的直接实验表征
DOI：
10.1021/acs.jpcb.8b09355
复制
发表时间：
2018-11-01
影响因子：
3.3
通讯作者：
Hong, Liang
中科院分区：
文献类型：
--
作者：
Liu, Zhuo;Yang, Chenxing;Hong, Liang
生物物理学的一个基本挑战是了解蛋白质动力学与其功能之间的联系。部分困难来自于蛋白质经常在相同的时间尺度上呈现局部原子运动和集体动力学的事实，并且挑战不同动力学模式的实验识别和量化。本文以冻干蛋白质为例，结合氘代技术和中子散射，在皮秒到纳秒的时间尺度上分离和表征了蛋白质中氢的自运动和重原子（C、O、N）的原子间集体运动.我们发现，氢原子提出了一个仪器分辨率依赖的非谐运动，这可以归因于局部侧群运动的热激活的发病。然而，蛋白质重原子在200 K附近表现出与仪器分辨率无关的非谐性，这是由于蛋白质结构在实验室平衡时间（100-1000 s）上的松弛解冻，整个生物大分子软化。
One fundamental challenge in biophysics is to understand the connection between protein dynamics and its function. Part of the difficulty arises from the fact that proteins often present local atomic motions and collective dynamics on the same time scales, and challenge the experimental identification and quantification of different dynamic modes. Here, by taking lyophilized proteins as the example, we combined deuteration technique and neutron scattering to separate and characterize the self-motion of hydrogen and the collective interatomic motion of heavy atoms (C, O, N) in proteins on the pico-to-nanosecond time scales. We found that hydrogen atoms present an instrument-resolution-dependent onset for anharmonic motions, which can be ascribed to the thermal activation of local side-group motions. However, the protein heavy atoms exhibit an instrument-resolutionindependent anharmonicity around 200 K, which results from unfreezing of the relaxation of the protein structures on the laboratory equilibrium time (100-1000 s), softening of the entire bio-macromolecules.