Issue
Europhys. Lett.
Volume 76, Number 4, November 2006
Page(s) 703 - 709
Section Interdisciplinary physics and related areas of science and technology
DOI http://dx.doi.org/10.1209/epl/i2006-10317-0
Published online 18 October 2006
Europhys. Lett., 76 (4), pp. 703-709 (2006)
DOI: 10.1209/epl/i2006-10317-0

Membrane adhesion via competing receptor/ligand bonds

M. 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

Abstract
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.

PACS
87.16.Dg - Membranes, bilayers, and vesicles.
64.75.+g - Solubility, segregation, and mixing; phase separation.
68.35.Np - Adhesion.

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