Fig. 5.

Unfolding force distribution. (A) The distribution of all unfolding forces (black) does not fit well to a model that assumes a single well-defined initial state (blue), which cannot account for the long tail at high forces, but it is described well by a model allowing for heterogenous initial states (red). (B) Most of the unfolding events belong to a single cluster (cyan) defined by an unfolding force below ∼30 pN and contour length below ∼12 nm. (C) The unfolding force distribution for the dominant cluster in B is well fit by both models used in A.