Feynman's Thermal Ratchet Mechanism on Kinesin Motors

Abstract

Kinesin is an ATP-driven molecular motor that moves processively along a microtubule in a stepwise manner. The steps occur not only in the forward direction, but also in the backward. Here, we have studied the bidirectional stepping mechanism of kinesin motors. The stepping mechanism of the forward and backward movements was well characterized by Feynman's thermal ratchet model. The driving force of the stepwise movement is essentially Brownian motion, but it is biased in the forward direction by utilizing the free energy released from the hydrolysis of ATP.