Walking motion of an overdamped active particle in a ratchet potential

Abstract

An active particle can convert its internal energy into mechanical work. We study a generalized energy-depot model of an overdamped active particle in a ratchet potential. Using well-known biological parameters for kinesin-1 and modeling ATP influx as a pulsed energy supply, we apply our model to the molecular motor system. We find that our simple model can capture the essential properties of the kinesin motor such as forward stepping, stalling, backward stepping, dependence on ATP concentration, and stall force. Our model might be quite universal in the sense that it is able to describe dynamics of various types of motors as long as realistic parameters for each motor species are adopted.

Stochastic dynamics of coupled active particles in an overdamped limit

“…Since an active Brownian particle model in an overdamped limit is a plausible candidate to describe the dynamics of a processive molecular motor in a cell, kinesin-1 was analyzed using our model. Kinesin-1 is a well-known processive cytoskeletal motor that exhibits discrete unidirectional motion, and our model successfully captured the primary features of the motor, including its forward and backward steppings and the stalling against an external load force [7,8].…”

A modified active Brownian dynamics model using asymmetric energy conversion and its application to the molecular motor system

“…From the conservation of energy in the depot, the internal energy e(t) at time t can be described as [45,46] …”

“…The generalized model was more or less successful in capturing primary features of molecular motors such as forward/backward stepping and stalling against an external load when the energy conversion rate was assumed to be a polynomial up to the fourth order of the particle's velocity [46]. However, four arbitrary parameters to be chosen properly are difficult to handle and in the stalling state the particle did not move at all instead of exhibiting equal numbers of forward and backward steps.…”

Two-dimensional motion of Brownian swimmers in linear flows

“…More recently, active particles (driven by an assumed internal mechanism) have been widely studied [7,[22][23][24][25][26][27][28][29]. For example, the Brownian motion of active bodies of simple shape, one sphere [3,30], multiple spheres [5], or ellipsoids [30] have been published.…”