DO DENATURANTS INTERACT WITH AROMATIC-HYDROCARBONS IN WATER
DO DENATURANTS INTERACT WITH AROMATIC-HYDROCARBONS IN WATER
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DOI：
10.1021/ja00073a050
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发表时间：
1993-10-06
影响因子：
15
通讯作者：
JORGENSEN, WL
中科院分区：
文献类型：
--
作者：
DUFFY, EM;KOWALCZYK, PJ;JORGENSEN, WL
通过计算尿素和胍离子（Gdm+）与苯以及尿素与萘在水中的相互作用自由能，研究了蛋白质变性剂与芳烃在水中直接相互作用的可能性.计算功能Monte Carlo统计力学模拟在25摄氏度的溶质和溶剂通过OPLS势函数和TIP 4P水模型的明确表示。反应坐标（r（c））被定义为芳烃的质量中心与离液剂的中心原子之间的距离，并且统计微扰理论（SPT）提供了在3-8埃范围内的自由能分布。在所有情况下，在接近4埃的2-3.5千卡/摩尔的阱深度下获得单个最小值。这支持直接离液剂-芳烃相互作用的存在。在水中的配合物的结构进行了讨论，并显示从最佳的气相结构的差异。考虑到在主-客体复合物中阳离子-π相互作用的兴趣，还对四甲基铵离子（TMA）与苯在水中的反应进行了计算，并得到了类似的自由能分布。
The possibility of direct interactions between protein denaturants and aromatic hydrocarbons in water has been investigated through the computation of free energy profiles for the approach of urea and guanidinium ion (Gdm+) to benzene and of urea to naphthalene in water. The calculations feature Monte Carlo statistical mechanics simulations at 25-degrees-C with explicit representation of the solutes and solvent via OPLS potential functions and the TIP4P water model. The reaction coordinate (r(c)) was defined as the distance between the center of mass of the arene and the chaotrope's central atom, and statistical perturbation theory (SPT) afforded the free energy profiles over the 3-8-angstrom range. In all cases, single minima were obtained with well depths of 2-3.5 kcal/mol near 4 angstrom. This supports the existence of direct chaotrope-arene interactions. The structures of the complexes in water are discussed and show differences from the optimal gas-phase structures. In view of the interest in cation-pi interactions in host-guest complexes, computations were also carried out for tetramethylammonium ion (TMA) with benzene in water and yielded a similar free energy profile.