Figure 3.

Histogram of the unfolding forces for the (I27-I28)₄ polyprotein. There are two clearly separated peaks, one at 211 pN and a second at 306 pN (n = 270). The line corresponds to Monte Carlo simulations of the unfolding forces (10,000 trials) of a protein chimera modeled as a double tetramer with two different domains placed in series. The unfolding rate for the first four domains was k_u⁰ = 7.0 × 10⁻⁴ s⁻¹, and the unfolding rate for the second four domains was k_u^{0 = 2.5 × 10−6 s−1. The unfolding distance for both domains was assumed to be Δx_u = 0.25 nm.}