The dynamics of peptide-water interactions in dialanine: An ultrafast amide I 2D IR and computational spectroscopy study
The dynamics of peptide-water interactions in dialanine: An ultrafast amide I 2D IR and computational spectroscopy study
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DOI：
10.1063/1.4991871
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发表时间：
2017-08-28
影响因子：
4.4
通讯作者：
Tokmakoff, Andrei
中科院分区：
文献类型：
--
作者：
Feng, Chi-Jui;Tokmakoff, Andrei
本文对Ala-Ala与水的动态相互作用进行了联合实验和计算研究，并将其酰胺I振动的超快2D IR和红外瞬时吸收光谱的结果与分子动力学(MD)模拟的光谱进行了比较。对实验数据进行了分析，描述了振动频率涨落、振动能量驰豫和化学交换过程。这些过程的起源在相同的潜在波动作用力下，允许根据多肽和相关溶剂的波动和构象动力学进行共同描述。通过将MD模拟的计算光谱与多力场和水模型进行比较，我们描述了水氢键涨落和切换过程的动力学如何作为控制退相和振动弛豫的摩擦源，并对引起光谱交换过程的水和肽的耦合运动进行了描述。由AIP出版公司出版。
We present a joint experimental and computational study of the dynamic interactions of dialanine (Ala-Ala) with water, comparing the results of ultrafast 2D IR and infrared transient absorption spectroscopy of its amide I vibration with spectra modeled from molecular dynamics (MD) simulations. The experimental data are analyzed to describe vibrational frequency fluctuations, vibrational energy relaxation, and chemical exchange processes. The origin of these processes in the same underlying fluctuating forces allows a common description in terms of the fluctuations and conformational dynamics of the peptide and associated solvent. By comparing computational spectroscopy from MD simulations with multiple force fields and water models, we describe how the dynamics of water hydrogen bond fluctuations and switching processes act as a source of friction that governs the dephasing and vibrational relaxation, and provide a description of coupled water and peptide motions that give rise to spectroscopic exchange processes. Published by AIP Publishing.