Figure 2.
Circular dichroism denaturation study of cruzain-K777 and procruzain. Minimal perturbations of the CD spectra of the cruzain-K777 complex with guanidinium hydrochloride (0 to 8 M GdnHCl final concentration, colored as indicated), and measured at (a) pH 5, (b) pH 7, and (c) pH 10 reflects the structural stability of the inhibited protease against chemical denaturation. (d) The CD spectra of procruzain in the absence of inhibitor, and measured at pH 10 indicates weaker overall stability against GdnHCl denaturation (0 to 5 M final concentration, colored as indicated). Comparisons of the θ222 band and estimated fractional helicity data are displayed in Supplemental Figure S3.