THE HYDROPHOBIC INTERACTION IS LONG-RANGE, DECAYING EXPONENTIALLY WITH DISTANCE
THE HYDROPHOBIC INTERACTION IS LONG-RANGE, DECAYING EXPONENTIALLY WITH DISTANCE
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DOI：
10.1038/300341a0
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发表时间：
1982-01-01
期刊：
影响因子：
64.8
通讯作者：
PASHLEY, R
中科院分区：
文献类型：
--
作者：
ISRAELACHVILI, J;PASHLEY, R
有机非极性分子（如碳氢化合物）在水中的相互吸引作用异常强烈。这种“疏水相互作用”1是疏水分子在水中溶解度非常低的原因，并且在胶束形成、生物膜结构和确定蛋白质构象方面具有核心作用2，3。人们曾经认为，因为相互作用是如此之强，有一个'疏水键'与它相关2，4;但现在认识到，相互作用涉及水分子的构型重排，因为两个疏水物质聚集在一起5 - 9，因此比典型的共价键范围更长。然而，一直没有实验信息提供有关的距离依赖性和有效范围的这种相互作用。从作为浸入电解质水溶液中的两个疏水表面之间的距离的函数的总力的测量中，我们精确地确定了由于疏水相互作用而引起的吸引分量，并且发现疏水相互作用具有与货车范德华色散力相同的范围，但是比范德华色散力强大约一个数量级;并且在0-10 nm范围内，它随距离呈指数衰减，衰减长度为0.01 nm。结果可以粗略地外推到分子间的相互作用，并表明在21 °C下，两个半径为R（nm）的疏水溶质分子在水中的相互作用自由能近似为ΔGH= − 40 RkJ mol−1，这与以前的估计一致。然而，疏水相互作用不是由于“疏水键”，其长程性质对蛋白质和其他大分子的折叠机制和速率以及平衡构象具有明显的影响。
The attractive interaction between organic nonpolar molecules, such as hydrocarbons, in water is unusually strong. This ‘hydrophobic interaction’1is responsible for the very low solubility of hydrophobic molecules in water, and has a central role in micelle formation, biological membrane structure, and in determining the conformations of proteins2,3. It was once believed that because the interaction is so strong there is a ‘hydrophobic bond’ associated with it2,4; but it is now recognized that the interaction involves the configurational rearrangement of water molecules as two hydrophobic species come together5–9and is therefore of longer range than a typical covalent bond. However, there has been no experimental information available concerning the distance dependence and effective range of this interaction. From measurements of the total force as a function of distance between two hydrophobic surfaces immersed in aqueous electrolyte solutions we have determined accurately the attractive component due to the hydrophobic interaction and found that the hydrophobic interaction has the same range as, but is about an order of magnitude stronger than, the van der Waals-dispersion force; and that in the range 0–10 nm it decays exponentially with distance with a decay length of ∼1 nm. The results can be roughly extrapolated to molecular interactions and show that the interaction free energy of two hydrophobic solute molecules of radiusR(nm) in water at 21 °C is approximately given by ΔGH= −40RkJ mol−1, which is in agreement with previous estimates. However, the hydrophobic interaction is not due to a ‘hydrophobic bond’, and its long-range nature has obvious implications for the mechanism and rates of folding as well as the equilibrium conformations of proteins and other macromolecules.