Physical analysis of a processive molecular motor: The conventional kinesin

We present a model that allows for the derivation of the experimentally accesible observables: spatial steps, mean velocity, stall force, useful power, efficiency and randomness, etc. as a function of the [adenosine triphosphate] concentration and an external load $F$. The model presents a minimum of adjustable parameters and the theoretical predictions compare well with the available experimental results.

Figure 1

Scheme of the effective potential with all the parameters and in an arbitrary scale.

Figure 2

Kinesin trajectories for $\left[\mathrm{ATP}\right]=5$ and $\left[\mathrm{ATP}\right]=2000\mu \mathrm{M}$ from numerical simulation of model (15).

Figure 3

Stall Force (pN) (using a position clamp) versus [ATP] concentration. The straight line is the analytical prediction (25) and dots are the experimental data of Ref. 1.

Figure 4

Mean velocity (nm/s) vs $F$ (pN) for two [ATP] concentrations. Points are from experimental data of Ref. 1. Lines are theoretical predictions.

Figure 5

Mean velocity vs [ATP] for different values of the load.

Figure 6

Randomness vs $F$ for $\left[\mathrm{ATP}\right]=2\mathrm{mM}$.

Figure 7

Randomness vs [ATP]. The values of $F$ are the same as in Fig. 5.