Fig. 2.

Solution spectroscopy and equilibrium unfolding of PP32. (A) Far-UV CD spectrum showing characteristic β-strand signal with a minimum at 217 nm. (B) Tryptophan fluorescence emission spectra in buffer (continuous black line) and 6 M urea (broken red line). (C) Urea-induced denaturation monitored by CD at 220 nm (filled black circle, continuous black line) and fluorescence (open red circle, broken red line). Lines result from fitting a two-state unfolding model to the data. The CD data are adapted from ref. 25.