Long-range DNA-water interactions
Long-range DNA-water interactions
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长程 DNA-水相互作用
DOI：
10.1016/j.bpj.2021.10.016
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发表时间：
2021
影响因子：
3.4
通讯作者：
Vinh, N. Q.
中科院分区：
文献类型：
--
作者：
Singh, Abhishek K;Wen, Chengyuan;Cheng, Shengfeng;Vinh, N. Q.
DNA仅在水环境中发挥作用，并根据水合程度采取不同的构象。水合水和水合DNA的动力学导致旋转和振荡偶极子，这反过来又引起了强烈的兆赫到太赫兹吸收。然而，研究水合作用对DNA动力学的影响以及受DNA影响的水分子的光谱特征是非常具有挑战性的，因为水在兆赫到太赫兹频率范围内具有很强的吸收性。作为回应，我们采用了高精度的兆赫兹到太赫兹介电光谱仪，辅助分子动力学模拟，调查水分子的动态内的水合壳的DNA以及集体振动运动的水合DNA，这是至关重要的DNA构象和功能。我们的研究结果表明，水分子在DNA溶液中的动力学是异质的，表现出四个不同的弛豫时间的层次，范围从108 ps到1 ns，和DNA链的水合结构可以延伸到远至1018 ps从其表面。水合DNA的低频集体振动模式已被确定，并发现对环境条件，包括温度和水合水平是敏感的。这些结果揭示了水合DNA动力学和DNA-水界面的关键信息，这些信息影响DNA的生化功能和反应性。
DNA functions only in aqueous environments and adopts different conformations depending on the hydration level. The dynamics of hydration water and hydrated DNA leads to rotating and oscillating dipoles that, in turn, give rise to a strong megahertz to terahertz absorption. Investigating the impact of hydration on DNA dynamics and the spectral features of water molecules influenced by DNA, however, is extremely challenging because of the strong absorption of water in the megahertz to terahertz frequency range. In response, we have employed a high-precision megahertz to terahertz dielectric spectrometer, assisted by molecular dynamics simulations, to investigate the dynamics of water molecules within the hydration shells of DNA as well as the collective vibrational motions of hydrated DNA, which are vital to DNA conformation and functionality. Our results reveal that the dynamics of water molecules in a DNA solution is heterogeneous, exhibiting a hierarchy of four distinct relaxation times ranging from ∼8 ps to 1 ns, and the hydration structure of a DNA chain can extend to as far as ∼18 Å from its surface. The low-frequency collective vibrational modes of hydrated DNA have been identified and found to be sensitive to environmental conditions including temperature and hydration level. The results reveal critical information on hydrated DNA dynamics and DNA-water interfaces, which impact the biochemical functions and reactivity of DNA.