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.pdf

物理化学学报( Wuli Haacue Xuebao
January
Acta Phys. -Chim. Sin. 2016, 32(1), 3
Article」
doi:10.3866/PKU.WHXB201512161
www.whxb.pku.edu.cn
尿素窟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12高毅勤]2
(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;
北京大学生物动态光学威像中心,北京100871)
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
中图分类号:O645.1
Molecular Dynamic Simulations of the Effects of Trimethylamine
N-oxide/Urea Mixture on the Hydration of Single-walled Carbon
Nanotube Interiors
YANG Li-jiang'2 GAO Yi-qin
Beijing National Laboratory for Molecular Sciences, College of Chemist and Molecular Engineering, Peking University,
Beijing 100871, P. R. China; Biodynamic Optical Imaging Center, Peking University, Beijing 100871, P. R. China
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 th
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- -oxide Carbon nanotube Hydration; Molecular dynamics
引言
们的衍生物コ。这些小分子对蛋白质的折叠、结构
渗透调节物质( osmolytes),主要包括各种多羟稳定性和功能都有重要的影响。尽管许多年来科
基化合物、糖类、有机溶剂和多种氨基酸以及它学家们对于渗透调节物质的研究已经积累了大量
Received: October 8 2015: Revised: December 15, 2015; Published on Web: December 16, 2015
Corrcspondingauthor.Email:gaoyq@pku.edu.cn;Tel:+86-10-62752431
The project was supported by the National Natural Science Foundation of China(213730 6, 21233002, 21125311, 21573006
国家自然科学基金(21373016,217233002,2125311,21573006)资助项目
@Editorial office of Acta Physico-chimica Sinica