Figure 7.

Inverse temperature dependence of the unfolding rate and unfolding free energy barrier. Filled points (•) are the experimentally determined unfolding rates. Circled points (⊙) are the inverse of the time taken to reach the transition state in MD simulation. In A–C, the solid lines are fits of Equation 3 (see text) to the experimental data. Dashed lines are fits of Equation 3 with ΔC_p^‡ = 0 to the high temperature MD data. The dotted line is the activation free energy, ΔG^‡(T), from the fit of Equation 3 with ΔC_p^‡ constant in units of RT. (A) Unfolding data for EnHD from Mayor et al. (2003). (B) Unfolding data for α₃D from Zhu et al. (2003). (C,D) Unfolding data for CI2. Experimental data are from Tan et al. (1996). The point at 1/T = 2.8 × 10⁻³ is the folding rate at the T_m. In D, the solid line is a fit of Equation 3 with ΔC_p^‡ = 6030 − 16.8T (Tan et al. 1996; see text). The dashed line is an extrapolation of Equation 3 with ΔC_p^‡ = 0 based on the values of ΔH^‡ and ΔS^‡ at 360 K (1/T = 2.78 × 10⁻³).