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Updated: Jan 11, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Exact statistics of helical wormlike chains with twist-bend coupling
Ashesh Ghosh1,2,3, Kranthi K Mandadapu2,3, David T Limmer1,3,4,5
1University of California, Berkeley, Department of Chemistry, California 94720, USA.
We developed a new method to analyze helical polymers, revealing how twist-bend coupling affects their structure and mechanics. This finding helps explain polymer behavior and re-evaluate biopolymer data.
Area of Science:
- Polymer Physics
- Biophysics
- Materials Science
Background:
- Helical wormlike chains are fundamental models for polymers.
- Twist-bend coupling is a crucial interaction in intrinsically twisted polymers.
- Understanding these interactions is key to predicting polymer properties.
Purpose of the Study:
- To present a Green's function solution for helical wormlike chains with twist-bend coupling.
- To evaluate the impact of twist-bend coupling on polymer structural and mechanical properties.
- To provide a framework for reinterpreting biopolymer experimental data.
Main Methods:
- Developed an exact Green's function solution for helical wormlike chains.
- Analyzed the influence of twist-bend coupling on chain properties.
- Investigated principal tangent correlations in intrinsically twisted polymers.
Main Results:
- Twist-bend coupling renormalizes persistence length and force-extension curves.
- Incorporation of twist-bend coupling induces oscillatory behavior in principal tangent correlations.
- The solution is applicable to general structural and mechanical property evaluations.
Conclusions:
- The presented solution offers a comprehensive framework for studying twist-bend coupling effects.
- Findings are relevant for understanding polymers like DNA bound to histones.
- Motivates re-evaluation of existing experimental data on biopolymers and synthetic polymers.
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