Adhesion Mediated by Competition of Ligand-Receptor Binding Against the Lateral Osmotic Pressure of Mobile Repellers

Abstract

A model system has been recently developed to study adhesion. It consists of a giant lipid bilayer vesicle with reconstituted lipo-polymers (repellers) as well as with lipo-ligands recognized by receptors covering the substrate. Adhesion in this system is studied theoretically. The state of the weak adhesion is shown to be dominated by the competition of the gravitation and the undulation repulsion between the membrane and the substrate. The state of the tight adhesion is formed by a competition of the ligand-receptor binding and the lateral osmotic pressure of the mobile repeller molecules. The regions of the weak and the tight adhesion are separated on the phase diagram by a whole transition region due to the scattering in parameters of vesicles.