Formation of adhesion domains in stressed and confined membranes

Abstract

The adhesion bonds connecting a lipid bilayer to an underlying surface may undergo a condensation transition resulting from an interplay between a short range attractive potential between them, and a long range fluctuation-induced potential of mean force. Here, we use computer simulations of a coarse-grained molecular model of supported lipid bilayers to study this transition in confined membranes, and in membranes subjected to a non-vanishing surface tension. Our results show that confinement may alter significantly the condensation transition of the adhesion bonds, whereas the application of surface tension has a very minor effect on it. We also investigate domain formation in membranes under negative tension which, in free membranes, causes the enhancement of the amplitude of membrane thermal undulations. Our results indicate that in supported membranes, this effect of a negative surface tension on the fluctuation spectrum is largely eliminated by the pressure resulting from the mixing entropy of the adhesion bonds.

Binding equilibrium and kinetics of membrane-anchored receptors and ligands in cell adhesion: Insights from computational model systems and theory

“…Instead, the binding of receptors and ligands has been described implicitly by interactions that depend on the membrane separation [32,[62][63][64][65][66][67][68][69]. In other previous elastic-membrane models, receptors and ligands are described by concentration fields rather than individual molecules [70][71][72][73][74][75][76][77][78][79], or receptor-ligand bonds are treated as constraints on the local membrane separation [33,[80][81][82][83].…”

Binding and segregation of proteins in membrane adhesion: theory, modeling, and simulations

“…2, the receptors and ligands are modelled as individual molecules that can bind and unbind. In other elastic-membrane models, receptors and ligands have been described via concentration fields and not as individual molecules [66][67][68][69][70][71][72][73][74][75], or receptor-ligand bonds have been treated as constraints on the local membrane separation [76][77][78][79][80].…”