  Using the model for the processive movement of a dimeric kinesin we proposed
before, we study the dynamics of a number of mutant homodimeric and
heterodimeric kinesins that were constructed by Kaseda et al. (Kaseda, K.,
Higuchi, H. and Hirose, K. PNAS 99, 16058 (2002)). The theoretical results of
ATPase rate per head, moving velocity, and stall force of the motors show good
agreement with the experimental results by Kaseda et al.: The puzzling dynamic
behaviors of heterodimeric kinesin that consists of two distinct heads compared
with its parent homodimers can be easily explained by using independent ATPase
rates of the two heads in our model. We also study the collective kinetic
behaviors of kinesins in MT-gliding motility. The results explains well that
the average MT-gliding velocity is independent of the number of bound motors
and is equal to the moving velocity of a single kinesin relative to MT.
