Figure 5.
Summary of the cruzain-inhibitor NMR titration data. Chemical shift perturbations of the selectively labeled 15N-Cys, 15N-His, and 13C-Met cruzain resonances upon addition of the inhibitors listed in Table 1. The bar charts represent the summation of the chemical shift perturbations, and are separated as Cys/His/Met residues located (a) in the substrate binding pocket, (b) proximally to the substrate binding pocket, and (c) outside the substrate binding pocket. Average shift perturbations corresponding to the same residue classifications (d-f) are also plotted. The inhibitors are categorized as covalent irreversible (black), covalent reversible (red), non-covalent (blue), and non-interacting/aggregators (yellow). Asterisks indicate exchange broadening of the resonance peaks upon addition of inhibitor. Shift perturbations of the Cys, His, and Met residues plotted individually are displayed in Supplemental Figs. S6-S8.