Figure 2.

500-MHz ¹H NMR spectra (50 mM sodium phosphate, 90% D₂O/10% H₂O, pH* 7.0, 30°C) of 2 mM horse cyt c and (A) no denaturant added (native state), (B) 6.3 M urea-d₄, (C) 7.0 M urea-d₄, and (D) 9.2 M urea-d₄. Resonances attributed to native (His-Met ligated) cyt c are labeled N(assignment) in A. Well-resolved resonances with relative intensity of three attributed to the non-native species L (or H) are labeled L^I, L^II, etc. (or H^I, H^II, etc.). Resolved non-native resonances with relative intensity of one are labeled with lowercase letters (h^I or l^I, etc.).