物理化学学报 >> 2016, Vol. 32 >> Issue (1): 313-320.doi: 10.3866/PKU.WHXB201512161

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尿素/氧化三甲胺混合溶剂影响单壁碳纳米管内部水合性质的分子动力学模拟

杨立江1,2,高毅勤1,2,*()   

  1. 1 北京大学化学与分子工程学院, 北京分子科学国家实验室, 北京 100871
    2 北京大学生物动态光学成像中心, 北京 100871
  • 收稿日期:2015-10-08 发布日期:2016-01-13
  • 通讯作者: 高毅勤 E-mail:gaoyq@pku.edu.cn
  • 基金资助:
    国家自然科学基金(21373016, 21233002, 21125311, 21573006)

Molecular Dynamic Simulations of the Effects of Trimethylamine-N-oxide/Urea Mixture on the Hydration of Single-Walled Carbon Nanotube Interiors

Li-Jiang YANG1,2,Yi-Qin GAO1,2,*()   

  1. 1 Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P.R.China
    2 Biodynamic Optical Imaging Center, Peking University, Beijing 100871, P.R.China
  • Received:2015-10-08 Published:2016-01-13
  • Contact: Yi-Qin GAO E-mail:gaoyq@pku.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21373016, 21233002, 21125311, 21573006)

摘要:

尿素是早已被人们认识的蛋白质变性剂,而氧化三甲胺则是最常用的蛋白质结构保护剂。虽然多年来被广泛应用在生物实验中,但是它们是如何在蛋白质结构形成中起作用,特别是氧化三甲胺是如何在高浓度尿素环境中起到抑制尿素蛋白变性作用的分子机制,至今仍然没有得到圆满解答。本文以单壁碳纳米管为模型疏水体系,采用分子动力学模拟研究尿素/氧化三甲胺混合溶液中纳米管内部水合性质,结果表明氧化三甲胺更易与水分子和尿素分子形成较强相互作用从而稳定了水溶液结构,这一结果亦表明了氧化三甲胺可以通过间接机制抵消尿素分子对于碳纳米管内部水合性质的影响。

关键词: 尿素, 氧化三甲胺, 碳纳米管, 水合作用, 分子动力学

Abstract:

Urea is known for protein denaturation.The counteracting effect of trimethylamine-N-oxide (TMAO) against urea-induced protein denaturation is also well established.However, what is largely unknown is the mechanism TMAO counteracts urea.In this article, the hydration of the interior of a simple single-walled carbon nanotube in a urea/TMAO mixture is studied as a model system for hydrophobic hydration using molecular dynamic simulations.The results show that TMAO counteracts the hydration effect of urea to the nanotube interior through strong interactions among TMAO, water, and urea.The strong interactions of TMAO and water stabilize the water structure, which counteracts the effects of urea indirectly.

Key words: Urea, Trimethylamine-N-oxide, Carbon nanotube, Hydration, Molecular dynamics

MSC2000: 

  • O645.11