GdmCl- and Urea-induced Unfolding Parameters for the hFXN Variants.

Parameter mNU is the slope of the linear dependency of free energy of unfolding (ΔGNU°) on denaturant concentration and ΔG°NU H2O is ΔG°NU at zero denaturant concentration. In the fittings, we used the predicted mNU values for GdmCl- and urea-induced unfolding considering a globular protein of a given molecular weigtht, 2.9 and 1.45 kcal mol−1 M−1 for hFXN90–210 and 2.5 and 1.25 kcal mol−1 M−1 for hFXN90–195 [68]. The units of mNU are kcal mol−1 M−1. Cm and free energy are M and kcal mol−1, respectively. CD signals are in [Θ] ×1 10−3 (deg cm2 dmol−1), and fluorescence intensity signals are arbitry units. The parameters were calculated by nonlinear least square fit of the data shown in Figure 4 as described in Materials and Methods.