Extract Motive Energy from Single-Molecule Trajectories.

Area of Science:

• Biophysics
• Statistical Mechanics
• Molecular Machines

Background:

• Single-molecule experiments are crucial for understanding biomolecule free-energy profiles.
• Molecular motor studies often involve analyzing trajectories as biased diffusion over an effective potential.
• The utility of this effective potential for motor studies was previously unclear.

Purpose of the Study:

• To introduce a method for deducing the effective potential from molecular motor trajectories.
• To investigate the application of this effective potential in characterizing motor properties.
• To enable easier measurement of key motor parameters like stall force.

Main Methods:

• Developed a method to deduce the effective potential from motor trajectories with realistic resolution.
• Applied the method to analyze trajectories from molecular motor models and experimental data.
• Validated the potential's ability to yield stall force and minimum energy price for directionality.

Main Results:

• The deduced effective potential accurately yields a molecular motor's stall force.
• Stall force can be extracted even from trajectories at zero or low resisting force.
• The method allows measurement of the minimum energy price for submicroscopic directionality.

Conclusions:

• The new method simplifies stall force measurement, making it accessible to force-incapable experiments.
• This approach enhances the study of molecular motors and their energy conversion efficiency.
• The findings provide a pathway to experimentally measure a key thermodynamic quantity for molecular motors.