Chemical–biological characterization of a cruzain inhibitor reveals a second target and a mammalian off-target

• Jonathan W. Choy,
• Clifford Bryant,
• Claudia M. Calvet,
• Patricia S. Doyle,
• Shamila S. Gunatilleke,
• Siegfried S. F. Leung,
• Kenny K. H. Ang,
• Steven Chen,
• Jiri Gut,
• Juan A. Oses-Prieto,
• Jonathan B. Johnston,
• Michelle R. Arkin,
• Alma L. Burlingame,
• Jack Taunton,
• Matthew P. Jacobson,
• James M. McKerrow,
• Larissa M. Podust and
• Adam R. Renslo

Beilstein J. Org. Chem. 2013, 9, 15–25, doi:10.3762/bjoc.9.3

• )-1-(benzenesulfonyl)-5-phenylpent-1-en-3-yl]amino]-3-(4-methylphenyl)-1-oxopropan-2-yl]pyridine-4-carboxamide (4), which is trypanocidal at ten-fold lower concentrations than for 1. We now find that the trypanocidal activity of 4 derives primarily from the inhibition of T. cruzi 14-α-demethylase

• of this new class of inhibitors. Keywords: activity-based probes; Chagas’ disease; cruzain; CYP51; 14-α-demethylase; hybrid drugs; Trypanosoma cruzi; Introduction The kinetoplastid protozoan Trypanosoma cruzi is the causative agent of Chagas’ disease, a leading cause of heart failure in endemic

• investigated are cruzain [7][8][9][10], the major cysteine protease active in the parasite, and T. cruzi CYP51 (TcCYP51), a 14-α-demethylase enzyme of the cytochrome P450 family required for ergosterol biosynthesis [11][12][13][14]. TcCYP51 is analogous to the fungal enzyme targeted by the azole class of