Twist dynamics of semiflexible polymer

TL;DR

This paper investigates the twist elasticity of semiflexible filaments like actin, highlighting how internal friction causes dissipation and affects the interpretation of experimental results.

Contribution

It introduces the significance of internal friction in semiflexible filaments and proposes analyzing twist elasticity through storage and loss moduli.

Findings

Internal friction influences twist elasticity measurements.

Dynamic and static methods yield different results due to dissipation.

Proposes a new framework for interpreting torsional experiments.

Abstract

A number of strange results have been reported for the twist elasticity of a semiflexible filament, actin. In particular dynamic and static methods for determining the torsional twist modulus give very different results. I show here that internal losses (friction) in a semiflexible filament could be an important cause of dissipation and that the interpretation of dynamic experiments should be made in terms of a storage and loss modulus for actin proteins.