FIGURE 3.

Frequency histograms of unbinding events obtained at the loading rate of 2060 pN/s. The bin size of unbinding force is 20 pN. Peaks in the histograms were fitted using Gaussian functions, as described in previous work (22). The maximum value of each Gaussian curve corresponds to the most probable unbinding forces F*. Inset shows typical experimental force-displacement measurements. The top curve indicates no occurrence of unbinding events. Unbinding peaks were selected only if they are well isolated; i.e., starting and ending near the baseline, for example those indicated by a black arrow in the blue, green, and red curves. No peak was considered in the orange curve.