title: Free energy and critical force for adhesion clusters.
abstract: Cooperative clusters of N parallel bonds confined to an anchoring surface by springs of stiffness ks are considered. The free energy of a cluster can be obtained from its force-displacement relation. The dissociation kinetics of the cluster can be modeled as the dissociation of an effective single bond. There is a critical force Fc beyond which the barrier for the cluster dissociation vanishes. Fc scales such as ks1/2 and Fc/N is small compared to the critical force of a single bond. The theoretical predictions of free energy landscape and cluster lifetime are supported by numerical simulations for large number of bonds. Our study suggests that experiments measuring force-displacement relations could be useful in exploring the dynamics of adhesion clusters.
authors.affiliation: Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 106, Republic of China.
authors.forename: Han-Jou
authors.initials: HJ
authors.lastname: Lin
authors.forename: Hsuan-Yi
authors.initials: HY
authors.lastname: Chen
authors.forename: Yu-Jane
authors.initials: YJ
authors.lastname: Sheng
authors.forename: Heng-Kwong
authors.initials: HK
authors.lastname: Tsao
mesh_terms: D000268:Adhesiveness; D000465:Algorithms; D000818:Animals; D001703:Biophysics / Q000379:methods*; D002448:Cell Adhesion; D016000:Cluster Analysis; D003198:Computer Simulation; D006801:Humans; D007700:Kinetics; D007962:Leukocytes / Q000166:cytology; D008024:Ligands; D015233:Models, Statistical; D008962:Models, Theoretical; D013816:Thermodynamics
chemical_list: D008024:Ligands