Figure 9.
The fraction of closed bonds as a function of the ECM stiffness EECM. We consider here 120 parallel filaments, each of which is tensed by 4 × 105 motors. Each of these motors possesses an effective stall force of 10 pN (34). The constant work Wmax varies between the curves (dotted line depicts Wmax = 13 fJ; dashed line, 7 fJ; solid line, 1 fJ), corresponding to between 0.6 and 8 kBT per motor. If the external rigidity is too high, a catch-bond cluster is unable to hold on and detaches.