Realistic Models of Biological Motion

TL;DR

This paper models biological motor protein motion using thermal ratchet physics, providing analytic solutions and exploring cooperative effects, aligning well with experimental data.

Contribution

It introduces realistic thermal ratchet models for motor proteins with analytic solutions and examines cooperative phenomena among multiple motors.

Findings

Analytic solutions for kinesin and myosin models.

Good agreement with experimental observations.

Discovery of novel cooperative transport phenomena.

Abstract

The origin of biological motion can be traced back to the function of molecular motor proteins. Cytoplasmic dynein and kinesin transport organelles within our cells moving along a polymeric filament, the microtubule. The motion of the myosin molecules along the actin filaments is responsible for the contraction of our muscles. Recent experiments have been able to reveal some important features of the motion of individual motor proteins, and a new statistical physical description - often referred to as ``thermal ratchets'' - has been developed for the description of motion of these molecules. In this approach the motors are considered as Brownian particles moving along one-dimensional periodic structures due to the effect of nonequilibrium fluctuations. Assuming specific types of interaction between the particles the models can be made more realistic. We have been able to give analytic solutions for our model of kinesin with elastically coupled Brownian heads and for the motion of the myosin filament where the motors are connected through a rigid backbone. Our theoretical predictions are in a very good agreement with the various experimental results. In addition, we have considered the effects arising as a result of interaction among a large number of molecular motors, leading to a number of novel cooperative transport phenomena.