Passive water penetration across the cell membrane by osmotic diffusion is essential for the homeostasis of cell volume, in addition to the protein-assisted active transportation of water. Since membrane components can regulate water permeability, controlling compositional variation during the volume regulatory process is a prerequisite for investigating the underlying mechanisms of water permeation and related membrane dynamics. However, the lack of a viable in vitro membrane platform in hypertonic solutions impedes advanced knowledge of cell volume regulation processes, especially cholesterol-enriched lipid domains called lipid rafts. By reconstituting the liquid-ordered (Lo) domain as a likeness of lipid rafts, we verified suppressed water permeation across the Lo domains, which had yet to be confirmed with experimental demonstrations despite a simulation approach. With the help of direct transfer of the Lo domains from vesicles to supported lipid membranes, the biological roles of lipid composition in suppressed water translocation were experimentally confirmed. Additionally, the improvement in membrane stability under hypertonic conditions was demonstrated based on molecular dynamics simulations.
Bibliographical noteFunding Information:
This work was supported by KIST Institutional Programs (Nos. 2E31521 and 2E31821). Y.-S.R. acknowledges support from a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT, No. 2021R1A2C2009236), the KU-KIST School Project, and a grant of the Information and Communications Promotion Fund (ICT promotion fund) through the National IT Industry Promotion Agency (NIPA), funded by the Ministry of Science and ICT(MSIT), Republic of Korea. D.J.A. acknowledges support from the National Research Foundation of Korea (NRF-2021R1A2C3009955, 2017M3D1A1039421) and the support from Korea University. The authors would like to thank Editage ( www.editage.co.kr ) for English language editing.
© 2022 American Chemical Society.
ASJC Scopus subject areas
- General Chemistry
- Colloid and Surface Chemistry