Thermodynamic behavior.

The heat capacity is computed using the fluctuation relation Cp = (var E)/T2. The self-avoiding random walk Rg is computing using Rg = (1.9Å)(Nres)0.6 for chemically-denatured proteins [19]. In the upper two panels (A) and (B), the Cp and Rg values are obtained from simulations started from either the native (blue line) or a random unfolded state (red line). In the lower two panels (C) and (D), the brown points are from high temperature simulations, while the green points (unfolded state) and blue points (folded state) are from simulations at the peak of the heat capacity. The simulation units are converted to physical units by assuming that the physical energy unit is 0.6 kcal/mol and that T = 1 corresponds to 300 K.