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arXiv · 2607.21133

Helical stability of double-stranded semiflexible chains with interstrand interactions

Farisan Dary·Donn Liew·Haiyi Liang·Ee Hou Yong
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Abstract

The mechanical and structural properties of dsDNA have been successfully described by models with varying levels of complexity and coarse-graining schemes. Prior work has characterized local stacking/twist effects and force-torque phase diagrams under external constraints. However, the role of base-pairing and torsional elasticity in global morphological transitions remain poorly characterized in the absence of external constraints. Here we investigate the delicate balance required for the strength of base-pairing interactions and the twisting energy to preserve the double-helix structure in a model made up of two semiflexible chains. We found that the model exhibits several distinct morphological phases: flat, random coil, double-helix, and the unwound double-helix. We calculate the Gauss linking number to characterize transitions between these phases.

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Farisan Dary, Donn Liew, Haiyi Liang, Ee Hou Yong. 2026-07-23. Helical stability of double-stranded semiflexible chains with interstrand interactions. https://arxiv.org/abs/2607.21133

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