Figure 5.

Plot of the dissociation rate of myo1c^IQ-tail from 2% PtdIns(4,5)P₂-containing membranes as a function of applied separating force (open, red circles). The dissociation rate of myo1c^IQ-tail measured at zero force via stopped-flow experiments (17) is shown as a star. A weighted linear fit (solid, red line) gives a slope of 150 ± 10 s⁻¹ pN⁻¹ and a y intercept of 0.45 ± 2.7 s⁻¹ (correlation coefficient = 0.998). Force-dependences of dissociation rates were calculated (Eq. 6) from ramp force histograms obtained at loading rates of (open, black squares) 250, (open, green circles) 930, and (open, blue triangles) 1800 pN/s. The force dependence of the rate of lipid extraction from the membrane at loading rate of 1100 pN/s was also calculated (open, magenta diamonds) from the ramp force distribution. Force-dependent dissociation rates derived from parameters obtained from the best-fits of the corresponding ramp-load experiments (Table 1) are plotted (dashed curves of the corresponding color) using Eq. 2.