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. 2015 Oct 7;290(49):29270–29280. doi: 10.1074/jbc.M115.681874

FIGURE 3.

FIGURE 3.

Effects of E496R, R713E, and E496R/R713E mutations on myosin enzymatic activity and in vitro actin sliding velocity. Myosins isolated from indirect flight muscles of wild-type transgenic control, E496R, R713E, and E496R/R713E lines were assessed for (A) Ca-ATPase activity, (B) basal Mg-ATPase activity, (C) actin-stimulated Mg-ATPase activity (Vmax), and (D) actin affinity relative to ATPase (Km). To calculate the latter two parameters, Mg-ATPase activities (see panel G) were fit with the Michaelis-Menten equation. E, catalytic efficiency (determined by dividing Vmax by Km). For the ATPase activity parameters, the histograms show calculated values, standard deviations and statistical significances from multiple experiments (n = 4). F, actin sliding velocity and standard deviations as assessed by video microscopy from multiple biological replicates (n = 3; at least 40 filaments tracked per replicate). G, comparison of actin-stimulated Mg-ATPase activity for myosins isolated from indirect flight muscles of wild-type transgenic control, E496R, R713E, and E496R/R713E lines. Basal Mg-ATPase activities were subtracted from all data points. For all parameters, statistical significance is denoted as: * = p < 0.05; ** = p < 0.01; *** = p < 0.001; ns = not significant.