Journal: Journal of Physical Chemistry Letters 15(16) (2024): 4437-4443
Author: Minho Lee1, 2, Euihyun Lee3, Ji-Hyun Kim1, 2, Hyonseok Hwang6, Minhaeng Cho4, 5, and Jaeyoung Sung1, 2
1 Creative Research Initiative Center for Chemical Dynamics in Living Cells, Chung-Ang University, Seoul 06974, Republic of Korea
2 Department of Chemistry, Chung-Ang University, Seoul 06974, Republic of Korea
3 Department of Chemistry, The University of Texas at Austin, TX 78757, USA
4 Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Republic of Korea
5 Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
6 Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon, Gangwon-do 24341, Republic of Korea
*Correspondence and requests for materials should be addressed to J.S. (email: jaeyoung@cau.ac.kr) and M.C. (email: mcho@korea.ac.kr).
https://doi.org/10.1021/acs.jpclett.4c00323
Water molecules confined between biological membranes exhibit a distinctive non-Gaussian displacement distribution, far different from 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, unaffected by changes in the intermembrane separation.