FIGURE 4.

ADP-interactions of wild-type and mutant myosins in the presence of actin. (A) Plot of the relative change of the observed rate constant (k _obs/k ₀) as obtained from single exponential fits to the fluorescence transients observed upon mixing pyrA∙Myo1B^wt in the presence of increasing ADP concentrations with excess ATP. (B) Normalized amplitudes of the slow phase (open circles) and fast phase (filled circles) as obtained from biexponentional fits to the fluorescence transients observed upon mixing 1 µM pyrA∙Myo1B^F387Y in the presence of increasing ADP concentrations with excess ATP. (C) Normalized amplitudes of the slow phase (open squares) and fast phase (filled squares) as obtained from biexponentional fits to the fluorescence transients observed upon mixing pyrA∙Myo1E^wt in the presence of increasing ADP concentrations with excess ATP. (D) Plot of the relative change of the observed rate constant (k _obs/k ₀) as obtained from single exponential fits to the fluorescence transients observed upon mixing 1 µM pyrA∙Myo1E^F388Y in the presence of increasing ADP concentrations with excess ATP.