Cross-linker unbinding and self-similarity in bundled cytoskeletal networks

TL;DR

This study investigates how molecular unbinding of cross-linkers and the self-similar structure of actin networks influence their mechanical properties, revealing a superposition principle that extends the frequency range of their elasticity.

Contribution

It introduces a concentration/time superposition principle based on cross-linker unbinding and network self-similarity, expanding understanding of actin network mechanics.

Findings

Unbinding of cross-linkers affects network elasticity under load.

Self-similarity enables a superposition principle for mechanical response.

Frequency range of network elasticity is broadened over 8 orders of magnitude.

Abstract

The macromechanical properties of purely bundled in vitro actin networks are not only determined by the micromechanical properties of individual bundles but also by molecular unbinding events of the actin binding protein (ABP) fascin. Under high mechanical load the network elasticity depends on the forced unbinding of individual ABPs in a rate dependent manner. Cross-linker unbinding in combination with the structural self-similarity of the network enables the introduction of a concentration/time superposition principle - broadening the mechanically accessible frequency range over 8 orders of magnitude.