Figure 5.

Dependence of the association rate constant of the actomyosin interaction on its sliding velocity. (A) Relationship between ATP concentration and the estimated association rate constant. At these ATP concentrations, the actin filament moved at 0.480–3.03 μm/s (see Fig. 3E). Bars indicate SE (n = 3–8). (B) Relationship between the sliding velocity (obtained from Fig. 3E) and the estimated association rate constant. Open circles, without reversible ATP binding (slope, solid line: 23.5 ± 1.39 (1/s)/(μm/s) (mean ± SE), coefficient of determination R², 0.936). Closed circles, with reversible ATP binding (slope, dotted line: 19.4 ± 1.32 (1/s)/(μm/s) (mean ± SE), coefficient of determination R², 0.922). Bars indicate SE (for p, n = 3–8; for velocity, n = 351–925).