Bauer Brad A, Lucas Timothy R, Meninger David J, Patel Sandeep
Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
Chem Phys Lett. 2011 May 27;508(4-6):289-294. doi: 10.1016/j.cplett.2011.04.052.
We investigate permeation energetics of water entering a model dimyristoylphosphatidylcholine (DMPC) bilayer via molecular dynamics simulations using polarizable Charge Equilibration (CHEQ) models. Potentials of mean force show 4.5-5.5 kcal/mol barriers for water permeation into bilayers. Barriers are highest when water coordination within the bilayer is prevented, and also when using force fields that accurately reproduce experimental alkane hydration free energies. The magnitude of the average water dipole moment decreases from 2.6 Debye (in bulk) to 1.88 Debye (in membrane interior). This variation correlates with the change in a water molecule's coordination number.
我们通过使用可极化电荷平衡（CHEQ）模型的分子动力学模拟，研究了水进入模型二肉豆蔻酰磷脂酰胆碱（DMPC）双层膜的渗透能。平均力势表明，水渗透进入双层膜存在4.5 - 5.5千卡/摩尔的势垒。当双层膜内的水配位被阻止时，以及使用能准确再现实验烷烃水合自由能的力场时，势垒最高。平均水偶极矩的大小从2.6德拜（在本体中）降至1.88德拜（在膜内部）。这种变化与水分子配位数的变化相关。
