Individual and ensemble molecular adhesion regulated by various physical factors

Abstract:

Reversible binding and unbinding between specific receptors and ligands mediate a variety of adhesion-based processes in cellular behaviors such as spreading, migration and polarization. Binding and unbinding of receptor-ligand bonds are commonly characterized by their association and dissociation kinetic rates, which are tightly regulated by various physical factors. In this talk, I will first present a transport-reaction coupling framework, demonstrating the force dependence of individual bond dissociation via a statistical version of Johnson-Kendall-Roberts model, the gap distance and separation speed dependence of individual bond association between reactant-bearing surfaces. The above-mentioned transport-reaction processes recover the on- and off-rate descriptions in close form, which are then applied to investigate the collective adhesion of multiple receptor-ligand bonds at the compliant interface between two anisotropic materials. The combined analyses and simulations show that the orientation of material anisotropy strongly affects the apparent softness felt by the adhesive bonds, thereby altering their ensemble lifetime by several orders of magnitude. An implication of the study is that distinct adhesion-based cellular behaviors can be achieved through remodeling of material anisotropy in either extracellular matrix or cytoskeleton.

 

Time: April 25, 2014 10:00-11:30 a.m

Location: N412,Meng Minwei science and technology building,Tsinghua University