Stability of Positively Charged Solutes in Water: A Transition from Hydrophobic to Hydrophilic

作者：Pascal Tod A; Lin Shiang Tai; Goddard William A III^*; Jung Yousung

来源：Journal of Physical Chemistry Letters, 2012, 3(3): 294-298.

DOI：10.1021/jz201612y

To improve the description of solvation thermodynamics of biomolecules, we report here the dependence of solvation on the curvature and surface charge of positively charged solutes in water based on extensive molecular dynamics simulations analyzed using the two-phase thermodynamic method. At a surface charge of +0.4e, the compensating forces of favorable electrostatic stabilization and entropic destabilization cancel almost exactly, representing a molecular crossover point from hydrophobic to hydrophilic behavior, independent of curvature. These results suggest that one should include charge-dependent entropic corrections to continuum models aimed at predicting the solvation free energies of large biomolecules.

• 出版日期2012-2-2