Cation-Mediated Nanodomain Formation in Mixed Lipid Bilayers
Cellular membranes are inhomogeneous in nature and are composed of various kinds of lipids and proteins in interaction with their environments. Ion interactions with biological membranes not only affect structure, dynamics, and stability of bilayers, but also affect protein binding, folding, aggregation, and insertion in a lipid bilayer environment. Molecular simulations can provide a mechanistic view of macroscopic experimental observables. Coarse-grained (CG) models, which allows us to explore longer time scales and larger systems, have yielded significant results in the understanding of lipid–lipid interaction or tail-induced phase separation in lipid mixtures. The chapter presents a generic Water-Explicit Polarizable MEMbrane (WEPMEM) lipid model for anionic and zwitterionic lipids with the inclusion of dipolar interactions in the lipid headgroup region. It suggests that cations of particular sizes have the ability to induce nanodomains in lipid bilayers, which can significantly affect structural and organizational properties of the bilayer and hence regulate function of cellular membranes.