Membrane adhesion via competing receptor/ligand bondsM. Asfaw, B. Rózycki, R. Lipowsky and T. R. Weikl
Max Planck Institute of Colloids and Interfaces - 14424 Potsdam, Germany
received 3 July 2006; accepted in final form 22 September 2006
published online 18 October 2006
The adhesion of biological membranes is controlled by various types of receptor and ligand molecules. In this letter, we present a statistical-mechanical model for membranes that interact via receptor/ligand bonds of two different lengths. We show that the equilibrium phase behavior of the membranes is governed by an effective double-well potential. The depths of the two potential wells depend on the concentrations and binding energies of the receptors and ligands. The membranes are unbound for small, and bound for larger potential depths. In the bound state, the length mismatch of the receptor/ligand bonds can lead to lateral phase separation. We derive explicit scaling laws for the critical points of unbinding and phase separation, and determine the prefactors by comparison with Monte Carlo results.
87.16.Dg - Membranes, bilayers, and vesicles.
64.75.+g - Solubility, segregation, and mixing; phase separation.
68.35.Np - Adhesion.
© EDP Sciences 2006