Discrete elastic model for stretching-induced flagellar polymorphs

Abstract

Force-induced reversible transformations between coiled and normal polymorphs of bacterial flagella have been observed in recent optical-tweezer experiment. We introduce a discrete elastic rod model with two competing helical states governed by a fluctuating spin-like variable that represents the underlying conformational states of flagellin monomers. Using hybrid Brownian dynamics Monte-Carlo simulations, we show that a helix undergoes shape transitions dominated by domain wall nucleation and motion in response to externally applied uniaxial tension. A scaling argument for the critical force is presented in good agreement with experimental and simulation results. Stretching rate-dependent elasticity including a buckling instability are found, also consistent with the experiment.

References in corpus (3)

• Synchronization of rotating helices by hydrodynamic interactions
• Twirling and Whirling: Viscous Dynamics of Rotating Elastica
• Stretching helical nano-springs at finite temperature

Cited by in corpus (10)

• Bacterial hydrodynamics
• Modelling the Mechanics and Hydrodynamics of Swimming E. coli
• How does a flexible chain of active particles swell?
• Force-extension curves of bacterial flagella
• Why Microtubules run in Circles - Mechanical Hysteresis of the Tubulin Lattice
• Zipping and Entanglement in Flagellar Bundle of E. Coli: Role of Motile Cell Body
• Flow properties and hydrodynamic interactions of rigid spherical microswimmers
• Crunching Biofilament Rings
• A Solvable Model for Polymorphic Dynamics of Biofilaments
• Confotronic Dynamics of Tubular Lattices