External mechanical force as an inhibition process in kinesin's motion.

We analysed published force-velocity data for kinesin using classical Michaelis-Menten kinetic theory and found that the effect of force on the stepping rate of kinesin is analogous to the effect of a mixed inhibitor in classical inhibition theory. We derived an analytical expression for the velocity of kinesin (the stepping rate, equal to the ATP turnover rate) as a function of ATP concentration and force, and showed that it accurately predicts the observed single molecule stepping rate of kinesin under a variety of conditions.