Figure 3.

Work loop analysis. (A) Representative work loop traces. Control (solid) and R759E-2 (shaded) work loop traces from single fibers run under identical ML strain and frequency conditions, 0.75% ML and 150 Hz. Both loops generated net positive work (counterclockwise loops as indicated by the arrows) with the mutant loop generating a small clockwise subloop (work absorption) at the beginning of shortening. (B) Power as a function of sinusoidal ML change from 0.0625% to 1.5% ML (peak to peak) at a frequency of 150 Hz. (C) Power as a function of frequency at a ML change of 0.75%. Data are from control (N = 10) and mutant R759E-2 (N = 12) fibers. Mean ± SE. (Asterisk) Statistically different from control fibers (Student's t-test, p < 0.05). Experiments were performed at 15°C.