Elasticity of a semiflexible filament with a discontinuous tension due to a cross-link or a molecular motor.

  title={Elasticity of a semiflexible filament with a discontinuous tension due to a cross-link or a molecular motor.},
  author={Mohammadhosein Razbin and Panayotis Benetatos and Annette Zippelius},
  journal={Physical review. E},
  volume={93 5},
We analyze the stretching elasticity of a wormlike chain with a tension discontinuity resulting from a Hookean spring connecting its backbone to a fixed point. The elasticity of isolated semiflexible filaments has been the subject in a significant body of literature, primarily because of its relevance to the mechanics of biological matter. In real systems, however, these filaments are usually part of supramolecular structures involving cross-linkers or molecular motors, which cause tension… 

Figures from this paper

Elasticity of connected semiflexible quadrilaterals.

This work analytically calculates the probability densities associated with the fluctuating tip and the corners of a grafted system of connected quadrilaterals and reveals that the force-extension relations depend on the contour length of the system, the bending stiffness, the geometrical angle and the number of the quadrillaterals, while the Poisson's ratio depends only on the ge graphically inclined angle.

Elasticity of a Filament with Kinks

Using the wormlike chain model, we analytically study the elasticity of a filament with kinks. We calculate the position probability density function and the force constant of a kinked filament with

Bimodal probability density characterizes the elastic behavior of a semiflexible polymer in 2D under compression.

The elastic behavior of a wormlike chain under compression is explored in terms of exact solutions for the associated probability densities and a bimodal shape of the probability density for the transverse fluctuations of the free end of a cantilevered polymer is found as fingerprint of its semiflexibility.

Orientational Fluctuations and Bimodality in Semiflexible Nunchucks

This article analytically calculate the distribution of bending fluctuations of a wormlike chain (WLC) consisting of three blocks with different bending stiffness and shows that, under certain conditions, there is a pronounced bimodality in the transverse fluctuations of the free end.

Grafted Semiflexible Nunchucks with a Magnetic Bead Attached to the Free End

Semiflexible nunchucks are block copolymers, which consist of two long blocks of high bending stiffness jointed together by a short block of low bending stiffness. Semiflexible nunchucks that consist

Elasticity of basic structural element in anisotropic macromolecular networks

Mechanical properties of some structures made by semiflexible biopolymers are studied based on analytical calculations of wormlike chain model and are valid for filaments in the weakly bending regime.

Inequivalence of fixed-force and fixed-extension statistical ensembles for a flexible polymer tethered to a planar substrate.

The analysis shows that confinement due to tethering causes ensemble inequivalence, irrespective of the polymer model, and qualitatively agrees with the analytical predictions of the Gaussian model.

Elasticity of a Filament with Kinks

Using the wormlike chain model, we analytically study the elasticity of a filament with kinks. We calculate the position probability density function and the force constant of a kinked filament with

Statistical ensemble inequivalence for flexible polymers under confinement in various geometries.

This work analyzes in both the Helmholtz and the Gibbs ensemble the pressure-volume equation of state of a chain in rectangular, spherical, and cylindrical confinement and recovers ensemble equivalence in the limit of squashing confinement.



Elasticity of cross-linked semiflexible biopolymers under tension.

In this combined limit, the elasticity of a weakly bending wormlike chain without constraints is recovered asymptotically and the increase in differential stiffness can be as large as 100% for small f or large numbers of cross-links.

Tension-induced binding of semiflexible biopolymers

The cross-over to the strongly bound state can be interpreted as a mechanism for force-stiffening which exceeds the capabilities of single-chain elasticity and thus available only to reversibly cross-linked polymers.

Mechanical response of active gels

It is shown that the coupling of the elasticity of the semiflexible filaments to the mechanical properties of the motors leads to contractile behavior of the gel, in qualitative agreement with experimental observations.

Force–extension relation of cross-linked anisotropic polymer networks

Cross-linked polymer networks with orientational order constitute a wide class of soft materials and are relevant to biological systems (e.g., F-actin bundles). We analytically study the nonlinear

Entropic forces generated by grafted semiflexible polymers.

In the stiff limit, where the persistence length of the polymer is larger than its contour length, it is found that the entropic force shows scaling behavior.

Stretching short biopolymers by fields and forces.

The exact average end-to-end distance and shape of the polymer for different boundary conditions are computed, and it is shown that boundary effects can lead to significant deviations from the well-known long-polymer results.

A bottom-up approach to cell mechanics

In vitro reconstitution of ‘functional modules’ of the cytoskeleton is now seen as a way of balancing the mutually conflicting demands for simplicity, which is required for systematic and quantitative studies, and for a sufficient degree of complexity that allows a faithful representation of biological functions.

Mechanics of biological networks: from the cell cytoskeleton to connective tissue.

This review focuses on the current progress in the field, with a primer into the basic physics of individual filaments and the networks they form, and a discussion of biological networks in the context of a broad spread of recent in vitro and in vivo experiments.

The gated gait of the processive molecular motor, myosin V

The mechanical interactions between mouse brain myosin V and rabbit skeletal F-actin are measured and it is proposed that the 36-nm steps of the double-headed motor are a combination of the working stroke of the bound head and a biased, thermally driven diffusive movement of the free head onto the next target zone.