Prediction of Catch-Slip Bond Transition of Kindlin2/β3 Integrin via Steered Molecular Dynamics Simulation

Kindlin2 is believed to be crucial in integrin activation, which mediates the cell–extracellular matrix adhesion and signaling, but the mechanoregulation of the interaction between Kindlin2 and integrin remains unclear. Here, we performed the so-called "ramp-clamp" steered molecular dynamics simulation on the crystal structure of Kindlin2 bound with β3 integrin. The results showed that the complex had a better mechanical strength for its rupture force of about 200 pN under pulling with the velocity of 1 Å/ns, and was mechanostable for its conformational conservation under constant tensile force (≤60 pN). The catch-slip bond transition with a force threshold of 20 pN was demonstrated by the dissociation probability, the interaction energy, the interface H-bond number, and the force-induced allostery of the complex. This study might provide a novel insight into force-dependent Kindlin2/integrin-related signaling and its structural basis in cellular processes as well as a rational SMD-based computer strategy for predicting the structure–function relationship of the stretched complex.