Elasticity of Stiff Biopolymers

TL;DR

This paper develops analytical models for the elasticity of stiff biopolymers like actin filaments, emphasizing boundary conditions and comparing with numerical results, to aid understanding of cellular cytoskeleton mechanics.

Contribution

It provides approximate analytical force-extension relations for stiff biopolymers, highlighting the impact of boundary conditions and enabling comparison with experiments.

Findings

Analytical force-extension relations derived for stiff polymers.

Boundary conditions significantly influence force-extension behavior.

Theoretical predictions can be tested with single molecule experiments.

Abstract

We present a statistical mechanical study of stiff polymers, motivated by experiments on actin filaments and the considerable current interest in polymer networks. We obtain simple, approximate analytical forms for the force-extension relations and compare these with numerical treatments. We note the important role of boundary conditions in determining force-extension relations. The theoretical predictions presented here can be tested against single molecule experiments on neurofilaments and cytoskeletal filaments like actin and microtubules. Our work is motivated by the buckling of the cytoskeleton of a cell under compression, a phenomenon of interest to biology.