FIG. 3.
Effect of (a) local (on a single cross bridge) and (b) global (on the full SF segment) force on the fraction η of bound actomyosin bonds in the SF segment in the absence of cell contraction (υs = 0). Predictions are shown in the case of an actomyosin slip bond α* = 0, moderate catch bond α* = 0.5, and strong catch bond α* = 1. These results clearly show the force-induced stabilization of the cross bridges as the bond catchiness is increased (a). They also show a dramatic disassembly of the actomyosin bundle when the applied force F* reaches its critical value (b). f* = f/ζ and F* = F/ζ.