FIG. 2.

(a) Energy landscape of the actomyosin bond in the direction of applied force. The bond needs to go over the energy barrier (or transition state) in order to switch from its bound to unbound state. For a catch bond, the height of the energy barrier increases with moderate force until it starts decreasing for larger magnitude. This ultimately yields a force-induced stabilization of the bond. (b) Relationship between the height ΔE_b of the energy barrier and applied force as predicted by the Pereverzev and Prezhdo model [42] used in this study, for different values of bond catchiness α^⋆. The case α^⋆ = 0 corresponds to a slip bond response.