Effect of mant-dATP/mant-ATP ratio on the displacement reaction for the three types of myofibrils. Myofibrils with increasing concentrations of mant-dATP from 0 to 100%. A, bovine masseter myofibrils. B, rabbit psoas myofibrils. C, porcine ventricle myofibrils (fast phase in white bars, and slow phase in black bars). For each myofibril type, the data for 100% mant-dATP + mavacamten are also shown. 3 μM mavacamten for bovine masseter and porcine ventricle, 30 μM mavacamten for rabbit psoas. The values for kobs are summarized in Table S1.