Mechanics of Single Molecular Motors and Chemical Thermodynamics of ATP Hydrolysis Catalyzed by Them

Abstract

A single processive and tightly-coupled molecular motor such as kinesin performs mechanical work by using the heat absorbed by the motor from the surroundings upon catalyzing spontaneously occurring ATP hydrolysis. This is a conclusion derived from a thermodynamic analysis of the mechano-chemical cycle of such single molecular motors together with an equation that relates work done by single molecular motors to the thermodynamics of ATP hydrolysis catalyzed by the motors. Analysis of motor models based on the thermodynamic approach leads to a general equation depicting the stepping motion of such molecular motors as a biased random walk.