Figure 3. Thermal and Chemical stabilities of URN1-FF at different pHs.

Thermal stabilities were studied monitoring the changes by (a) far-UV CD at 222 nm and by (b) intrinsic fluorescence at 350 nm. Equilibrium urea unfolding curves at 310 K were followed by (c) far-UV CD at 222 nm and by (d) tryptophan intrinsic fluorescence at 350 nm. Protein samples are represented at pH 2.0 by squares; pH 2.5, diamonds; pH 3.0, circles; and pH 5.7, triangles.