Figure 3: Convergence to the denatured stateD0 . a) 15N-HSQC spectra (zoom) of mHIV-1-PR1-95 showing T80 in 12 different15N-HSQC spectra recorded under various denaturing conditions. All peaks converge to the same position for T80 inD0 . Red peaks: urea 8 M (light red), urea 6 M (medium red) and urea 4 M (dark red). Green peaks: acetic acid 45% (light green), acetic acid 25% (medium green) and acetic acid 9% (dark green). Blue peaks: GdmCl 4 M (light blue), GdmCl 2 M (medium blue), GdmCl 1 M (dark blue). Purple peaks: sodium phosphate 20 mM, pH 6) at 5oC (light violet), 15 oC (dark violet). Black peaks: sodium phosphate 20 mM, pH 6 at 25oC (denatured state D0 ). b) Schematic of T80 1H chemical shifts of mHIV-1-PR as a function of denaturant concentrations; the x-values are annotated in the graph (red: urea; blue: GdmCl; green: acetic acid; purple: different temperatures; black: physiological condition at 25 oC (Dphys state)). All 1H chemical shifts converge to the D0 state value. c) Same for 15N chemical shifts.