Waiting time distributions in hybrid models of motor-bead assays: A concept and tool for inference

Abstract

In single-molecule experiments, the dynamics of molecular motors are often observed indirectly by measuring the trajectory of an attached bead in a motor-bead assay. In this work, we propose a method to extract the step size and stalling force for a molecular motor without relying on external control parameters. We discuss this method for a generic hybrid model that describes bead and motor via continuous and discrete degrees of freedom, respectively. Our deductions are solely based on the observation of waiting times and transition statistics of the observable bead trajectory. Thus, the method is non-invasive, operationally accessible in experiments and can, in principle, be applied to any model describing the dynamics of molecular motors. We briefly discuss the relation of our results to recent advances in stochastic thermodynamics on inference from observable transitions. Our results are confirmed by extensive numerical simulations for parameters values of an experimentally realized F1-ATPase assay.

References in corpus (7)

• Thermodynamic uncertainty relation for biomolecular processes
• Universal bound on the efficiency of molecular motors
• Entropy production and coarse-graining in Markov processes
• Fluctuation relations and coarse-graining
• Coarse graining of master equations with fast and slow states
• Effective rates from thermodynamically consistent coarse-graining of models for molecular motors with probe particles
• Coarse graining of biochemical systems described by discrete stochastic dynamics