Particle-Based Modeling of Living Actin Filaments in an Optical Trap

Area of Science:

• Biophysics
• Computational Biology

Background:

• Actin filaments are crucial cellular components involved in various dynamic processes.
• Understanding the mechanical properties of actin bundles is essential for cell mechanics.

Purpose of the Study:

• To investigate the structural and dynamical properties of actin filament bundles interacting with an external load.
• To model the behavior of living filaments capable of polymerization and depolymerization.

Main Methods:

• Coarse-grained molecular dynamics simulations.
• Particle-based approach representing actin units.
• Reactive grand canonical ensemble simulation.

Main Results:

• Filament bundle dynamics against a mobile wall resemble an over-damped Brownian oscillator.
• The model accurately captures equilibrium structural and dynamical properties.
• The pressing wall influences the kinetic rates of filament (de)polymerization.

Conclusions:

• The developed model serves as a valuable tool for studying bundles of living filaments.
• Simulation results align well with experimental and theoretical findings.
• The study provides insights into the mechanical behavior of cytoskeletal structures.