Inter-layer coupling strength in lipid bilayer can control the size of lipid domains

Abstract

In this article, we investigate the effect of the inter-layer interaction strength across the opposed layers of a lipid bilayer using dissipative particle dynamics (DPD) simulations. The lipid bilayer, immersed in water, was composed of two types of lipids representing saturated and unsaturated lipids. This research focuses on the situations where the lipid bilayer nears its critical temperature. In this situation, lipid domains in this regime are small, unstable, and have short lifespans. The behavior of these lipid domains resembles the concept of lipid rafts in plasma membranes. It is postulated that each function of lipid rafts requires a different time scale. Recent research also shows that the lifetime of a lipid raft depends on its size. Our findings indicate that the size and existence of raft-like lipid domains depend on the strength of the coupling between layers. Strong coupling strengths tend to stabilize the lipid domain, resulting in larger sizes compared to weaker coupling.