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Updated: Jun 14, 2026
11:41
Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Length-dependent force characteristics of coiled coils
1Physics Department, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
Summary
We developed a new model for protein coiled coils, revealing how helix deformation and hydrophobic interactions dictate their structure and stability. Shorter coils unfold at lower forces, but this force becomes independent of length for longer coils.
Area of Science:
- Structural biology
- Biophysics
- Computational biology
Background:
- Coiled-coil domains are crucial protein structures formed by alpha helices.
- Hydrophobic residue packing drives helix supercoiling, but helix deformation energy also plays a role.
Purpose of the Study:
- To develop a coarse-grained atomistic model for coiled coils.
- To investigate the interplay between hydrophobic energy and helix deformation energy.
- To understand the force-extension properties of coiled coils.
Main Methods:
- Developed a coarse-grained atomistic model incorporating hydrophobic energy and helix deformation cost.
- Simulated coiled coil formation and stability.
- Analyzed force-extension properties and unzipping behavior.
Main Results:
- The model predicts a structural transition from non-coiled-coil to coiled-coil states based on deformation energy.
- The model accurately reproduces natural coiled coil structures and experimental unzipping data.
- Shorter coiled coils unfold at lower forces, with unfolding force becoming length-independent for longer coils.
Conclusions:
- Coiled coil formation is governed by a balance between hydrophobic driving forces and helix deformation costs.
- The developed model provides insights into coiled coil stability and mechanical properties.
- The model's predictions align with experimental observations of coiled coil behavior.
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