Relation between cooperative molecular motors and active Brownian particles

Area of Science:

• Statistical physics
• Biophysics
• Soft matter physics

Background:

• Active Brownian Particles (ABPs) model self-propelled motion using nonlinear Langevin equations.
• Coupled Molecular Motors (CMMs) are crucial for biological processes requiring coordinated movement.

Purpose of the Study:

• To establish a connection between the Coupled Molecular Motors (CMMs) model and the Active Brownian Particles (ABPs) model.
• To investigate the dynamic features of CMMs that may not be captured by ABPs.

Main Methods:

• Utilized two independent numerical methods: stationary velocity distribution and Kramers-Moyal coefficients.
• Analyzed the stochastic dynamics of CMMs and compared them to ABP models.
• Examined the power spectrum of velocity fluctuations for both models.

Main Results:

• Established a strong agreement between CMM and ABP models for parameter extraction, independent of motor number (N) for sufficiently large N.
• Demonstrated that ABPs can effectively simplify the description of CMM systems under certain conditions.
• Identified a distinct peak at finite frequency in the CMM velocity fluctuation power spectrum, absent in ABPs.

Conclusions:

• CMMs can be approximated by simpler ABP models for parameter estimation, simplifying complex biological systems.
• The ABP model is insufficient to capture the full dynamic complexity of CMMs, particularly the observed power spectrum peak.
• CMMs possess richer dynamic features than ABPs, highlighting limitations of simpler models in fully representing biological motor functions.