Fig. 5.

P_b/P_f ratio (no. of forward steps/no. of backward steps calculated from trajectories of 200 ms) is plotted from trajectories of forward motion with force applied on the opposite direction (as in Fig. 4) and trajectories of backward motion with force applied on the same direction. Exponential fits for Δε = 3 kcal/mol (blue) and 4 kcal/mol (red) (A) and for Δε = 5 kcal/mol (blue) and 6 kcal/mole (red) (B) are shown. The stall force for each Δε is calculated as the force where P_b/P_f = 1. (C) Linear fit of these stall forces (plotted as green dots) for different Δε values.