Water molecules confined between biological membranes exhibit a distinctive non-Gaussian displacement distribution, far different from that of bulk water. Here, we introduce a new transport equation for water molecules in the intermembrane space, quantitatively explaining molecular dynamics simulation results. We find that the unique transport dynamics of water molecules stems from the lateral diffusion coefficient fluctuation caused by their longitudinal motion in the direction perpendicular to the membranes. We also identify an interfacial region where water possesses distinct physical properties, which is unaffected by changes in the intermembrane separation.

中文翻译：

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限制在脂膜之间的水分子的传输动力学

限制在生物膜之间的水分子表现出独特的非高斯位移分布，与散装水的分布截然不同。在这里，我们引入了膜间空间中水分子的新输运方程，定量解释了分子动力学模拟结果。我们发现水分子独特的传输动力学源于其在垂直于膜的方向上的纵向运动引起的横向扩散系数波动。我们还确定了一个界面区域，其中水具有独特的物理性质，不受膜间分离变化的影响。