A New Look at Dynamic Force Spectroscopy of Adhesion Bonds

TL;DR

This paper presents a new model for dynamic force spectroscopy of adhesion bonds, predicting rupture force distributions, their dependence on pulling velocity, and effects of conformational changes, with experimental validation and novel insights.

Contribution

It introduces a comprehensive model that predicts rupture force distributions, velocity dependence, and conformational effects, advancing understanding of single-molecule adhesion mechanics.

Findings

Distribution of rupture forces is asymmetric and experimentally observed.

Mean rupture force scales with lnV^{2/3} dependence on pulling velocity.

Rebinding at low velocities causes intermittent force behavior.

Abstract

Dynamic force spectroscopy of single molecules is described by a model which predicts a distribution of rupture forces, the corresponding mean rupture force and variance, all amenable to experimental tests. The distribution has a pronounced asymmetry which has recently been observed experimentally. The mean rupture force follows a lnV to the power of 2/3 dependence on the pulling velocity V and differs from earlier predictions.Interestingly, at low pulling velocities a rebinding process is obtained whose signature is an intermittent behavior of the spring force which delays the rupture. An extension to include conformational changes of the adhesion complex is proposed which leads to the possibility of bimodal distributions of rupture forces.