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Updated: Apr 7, 2026
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DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers
Published on: October 25, 2017
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Cylindrical confinement of semiflexible polymers
Pablo Vázquez-Montejo1, Zachary McDargh1, Markus Deserno1
1Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA.
Summary
We describe polymer loops binding to cylinders, detailing how loop length affects energy, torque, and stability. Some states become stable with increased length, offering insights into processes like membrane fission.
Area of Science:
- Polymer physics
- Biophysics
- Materials science
Background:
- Understanding polymer behavior is crucial in various scientific fields.
- Semiflexible polymers interacting with cylindrical structures present complex physical challenges.
- Previous studies have explored polymer-cylinder interactions, but equilibrium states require further elucidation.
Purpose of the Study:
- To characterize equilibrium states of a closed semiflexible polymer binding to a cylinder.
- To investigate the influence of loop length on energy, axial torque, and contact force.
- To determine the stability of bound states under confinement and constriction.
Main Methods:
- Analysis of equilibrium states based on loop length, number of oscillations (n), and winding number (p).
- Evaluation of energy, conserved axial torque, and contact force for different states.
- Stability analysis of confined and exterior bound states.
Main Results:
- Bound states are classified by integers n and p, with p being a topological invariant.
- Ground states (n=1) and excited states (n≥2) exhibit distinct behaviors with increasing loop length.
- Confined states can transition from unstable to stable, while exterior states may be unstable or topologically obstructed from unbinding.
- A p=2, n=1 state acts as a stable constriction, potentially relevant to membrane fission.
Conclusions:
- Loop length and topological winding number (p) dictate the equilibrium states and stability of polymers bound to cylinders.
- The study reveals critical transitions in stability for confined states.
- Findings suggest a model for understanding mechanistically how dynamin rings mediate membrane fission.
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