Stochastic dynamics of adhesion catch-slip bond cluster

TL;DR

This paper develops a stochastic model for biological bond clusters, analyzing their dissociation dynamics under force, revealing how cluster size and rebinding rates influence their stability and catch-slip behavior.

Contribution

It introduces an analytical stochastic model for bond clusters, including solutions for specific limits, and elucidates how cluster size and rebinding affect catch-slip bond dynamics.

Findings

Cluster size has little effect on lifetime when rebinding is absent.

Single catch bonds dominate the decay in large clusters.

Rebinding enhances catch behavior in bond clusters.

Abstract

We present a general stochastic dynamic model of a cluster of biological complexes with fluctuating dissociation and association rates. The master equation has analytical solutions in two limiting cases: the vanishing force with reflecting boundary condition and slow reaction limit. In particular, the latter can describe the dynamics of a catch-slip bond cluster under a constant force. We find that if the rebinding rate vanishes, the size of the cluster matters little to the cluster lifetime within the whole catch force regime. The large cluster rapidly decays and single catch bond governs the final dynamic behaviors of the cluster. The catch behavior would be further amplified in the presence of large nonvanishing rebinding rates.