Skip to main content
. 2015 Nov 9;112(47):14593–14598. doi: 10.1073/pnas.1517566112

Fig. 2.

Fig. 2.

Kinetics of the recovery stroke. (A and B) The kinetics of lever arm swing during the recovery stroke was measured by mixing 0.25 µM MV-F.QSY (A) or MV-F.IAANS (B) with different concentrations of ATP. A biphasic fluorescence increase (FlAsH–QSY pair with 500 µM ATP) (A, Inset) or a decrease (IAANS–FlAsH pair with 500 µM ATP) (B, Inset) was observed. The fast and slow phases are plotted as a function of ATP concentration, and the fast phase was fit to a hyperbola. The maximum rate of the fast phase was 330 ± 7⋅s−1 (MV-F.QSY) and 312 ± 12⋅s−1 (MV-F.IAANS). The observed rate of ATP-induced enhancement in tryptophan fluorescence in MV is plotted in A and fit to a hyperbola to determine the rate constant for the formation of the hydrolysis-competent state (332 ± 28⋅s−1). Control traces of the respective donor-alone and acceptor-alone are also shown in the Insets. (C) The relative amplitudes of the fast and slow phases are plotted as a function of ATP concentration.