A nonequilibrium power balance relation for analyzing dissipative filament dynamics

Area of Science:

• Biophysics
• Soft Matter Physics
• Cell Biology

Background:

• Biofilaments (e.g., actin, microtubules) and cellular structures (cilia, flagella) are subject to complex external forces.
• Efficient characterization of filament mechanics is crucial for understanding cellular processes.
• Existing methods for mechanical characterization can be time-consuming or require multiple experiments.

Purpose of the Study:

• To develop and validate a dynamic power balance approach for studying non-equilibrium filament dynamics.
• To provide an efficient method for characterizing biofilament mechanics using single or high-throughput experiments.
• To experimentally determine the friction coefficient of microtubules on kinesins.

Main Methods:

• Theoretical modeling using a dynamic power balance approach.
• Experimental validation using microtubule gliding assay dynamics.
• Analysis of microtubule buckling events to determine mechanical parameters.

Main Results:

• The dynamic power balance approach successfully models non-equilibrium filament dynamics.
• Experimental determination of the lateral friction coefficient for microtubules on kinesins.
• Discovery of anisotropic friction for microtubules on kinesins, contrary to common assumptions.
• Demonstration that a single time-dependent experiment can determine multiple unknown parameters if one is known.

Conclusions:

• The dynamic power balance method offers an efficient route to characterize biofilament mechanics.
• Friction in microtubule-kinesin interactions is anisotropic, similar to hydrodynamic friction.
• This approach enables comprehensive mechanical analysis from minimal experimental data, advancing biophysics research.