Dynamical bond cooperativity enables very fast and strong binding between sliding surfaces

TL;DR

This paper investigates dynamical cooperativity in driven systems, revealing how different bond modes interact to produce rapid and strong binding between sliding surfaces, with implications for biological adhesion and friction.

Contribution

It introduces a model of dynamical cooperativity involving two bond modes and demonstrates how they can produce fast, strong binding in non-equilibrium conditions.

Findings

Cooperative interactions lead to effective single-mode behavior.

Fast, strong bonds can dominate under certain conditions.

Results have implications for biological adhesion under flow.

Abstract

Cooperative binding affects many processes in biology, but it is commonly addressed only in equilibrium. In this work we explore dynamical cooperativity in driven systems, where the cooperation occurs because some of the bonds change the dynamical response of the system to a regime where the other bonds become active. To investigate such cooperativity we study the frictional binding between two flow driven surfaces that interact through a large population of activated bonds. In particular, we study systems where each bond can have two different modes: one mode corresponds to a fast forming yet weak bond, and the other is a strong yet slow forming bond. We find considerable cooperativity between both types of bonds. Under some conditions the system behaves as if there were only one binding mode, corresponding to a strong and fast forming bond. Our results may have important implications on the friction and adhesion between sliding surfaces containing complementary binding motifs, such as in the case of cells binding to the vessel walls under strong flowing conditions.