FIG 5.

NMR binding of FK506 and APX879 to the human, A. fumigatus, and M. circinelloides FKBP12 proteins. (A to C) Initial (0:1; in black) and final (2:1; in red) ¹⁵N-HSQC of the titration of APX879 with the human (A), A. fumigatus (B), and M. circinelloides (C) FKBP12 proteins. The FK506 final titration point (2:1) with the respective proteins is shown in blue for reference. Peaks doubling when protein is fully bound to APX879 are indicated by green squares (see Fig. S5 for full titration and zoomed regions where peak doublings are observed). (D) Protein chemical shift perturbation due to FK506 and APX879 binding. The red dashed line represents significant chemical shift perturbations (≥ protein mean + 1 standard deviation [SD]).