Figure 4. Urea-induced equilibrium denaturation curves of profilin-1.

(A) Ratio between fluorescence emitted at 369 and 319 nm. (B) Mean residue ellipticity per residue at 222 nm. (C) Fraction of folded protein calculated from the fluorescence data reported in panel (A) (orange circles) and from the CD data shown in panel (B) (green squares). The fraction folded was calculated with equation (1). In all panels, the solid line represents the best fits of the data points to the equation edited by Santoro and Bolen²⁵.