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The Mechanics of (Poro-)Elastic Contractile Actomyosin Networks As a Model System of the Cell Cytoskeleton
Published on: March 10, 2023
Langevin network model of myosin
Benjamin T Miller1, Wenjun Zheng, Richard M Venable
1Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
The Journal of Physical Chemistry. B
|March 4, 2008
Summary
The Langevin network model (LNM) reveals protein dynamics. All elastic network model (ENM)-like modes in myosin II are overdamped, with distinct low-frequency modes between pre- and post-power stroke states.
Area of Science:
- Biophysics
- Computational Biology
- Protein Dynamics
Background:
- Protein dynamics are crucial for function.
- Elastic Network Models (ENMs) simplify protein dynamics.
- Langevin mode theory accounts for solvent effects.
Purpose of the Study:
- To develop and apply the Langevin Network Model (LNM) for protein dynamics.
- To investigate the dynamics of myosin II.
- To compare protein dynamics in different functional states.
Main Methods:
- Combined Langevin mode theory with coarse-grained elastic network models (ENMs).
- Assigned hydrodynamic radii to alpha-carbons.
- Utilized Rotne-Prager tensor for hydrodynamic interactions.
- Analyzed myosin II structures (PDB: 1VOM, 1Q5G) and a myosin lever arm model.
Main Results:
- All ENM-like modes in myosin II are overdamped at physiological water viscosities.
- Low-frequency LNM modes differ significantly between pre- and post-power stroke myosin II structures.
- Mode coupling increases with deviation from linearity in myosin lever arm models.
- LNM mode decay times are shorter than rotational tumbling times for lysozyme and myosin.
Conclusions:
- The LNM provides a framework for studying protein dynamics with solvent effects.
- Myosin II dynamics are characterized by overdamped modes and distinct conformational states.
- The myosin lever arm's flexibility influences mode coupling, impacting function.
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