Membrane domain formation induced by binding/unbinding of curvature-inducing molecules onto both membrane surfaces

TL;DR

This study uses meshless membrane simulations to explore how curvature-inducing molecules bind, unbind, and move across membrane surfaces, leading to various domain patterns in equilibrium and nonequilibrium states.

Contribution

It introduces a simulation framework to analyze membrane domain formation driven by binding/unbinding and flip-flop of curvature-inducing molecules.

Findings

Checkerboard, stripe, and spot domain patterns in symmetric conditions.

Kagome-lattice and thread-like domains in asymmetric conditions.

Flow of molecules between solutions in nonequilibrium steady states.

Abstract

The domain formation of curvature-inducing molecules, such as peripheral or transmembrane proteins and conical surfactants, is studied in thermal equilibrium and nonequilibrium steady states using meshless membrane simulations. These molecules can bind onto both surfaces of a bilayer membrane and also move to the opposite leaflet by a flip-flop. In symmetric conditions for the two leaflets, the membrane domains form checkerboard patterns in addition to stripe and spot patterns. The unbound membrane stabilizes the vertices of the checkerboard. In asymmetric conditions, the domains form kagome-lattice and thread-like domains. In the nonequilibrium steady states, a flow of the binding molecules between the upper and lower solutions can occur via the flip-flop.