New perspectives on hydrophobic effects Original Research Article

Recent breakthroughs in the theory of hydrophobic effects permit new analyses of several characteristics of hydrophobic hydration and interaction. Heat capacities of non-polar solvation, and their temperature dependences, are analyzed within an information theory approach, using experimental information available from bulk liquid water. Non-polar solvation in aqueous electrolytes is studied by computer simulations, and interpreted within the information theory. We also study the preferential solvation of small non-polar molecules in heavy water (D2O) relative to light water (H2O) and find that this revealing difference can be explained by the higher compressibility of D2O. We develop a quasi-chemical description of hydrophobic hydration that incorporates the hydration structure and permits quantum-mechanical treatment of the solute. Finally, these new results are discussed in the context of hydrophobic effects in protein stability and folding, and of mesoscopic hydrophobic effects such as dewetting.