Coexistence of dilute and densely packed domains of ligand-receptor bonds in membrane adhesion

¹ II. Institut für Theoretische Physik, Universität Stuttgart - Stuttgart, Germany, EU
² Institut für Theoretische Physik and Excellence Cluster: Engineering of Advanced Materials, Universität Erlangen-Nürnberg - Erlangen, Germany, EU

Received: 10 February 2012
Accepted: 9 July 2012

Abstract

We analyze the stability of micro-domains of ligand-receptor bonds that mediate the adhesion of biological model membranes. After evaluating the effects of membrane fluctuations on the binding affinity of a single bond, we characterize the organization of bonds within the domains by theoretical means. In a large range of parameters, we find the commonly suggested dense packing to be separated by a free energy barrier from a regime in which bonds are sparsely distributed. If bonds are mobile, a coexistence of the two regimes should emerge, which agrees with recent experimental observations.