title: Nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitors as promising new leads for Chagas disease chemotherapy.
abstract: A century after discovering that the Trypanosoma cruzi parasite is the etiological agent of Chagas disease, treatment is still plagued by limited efficacy, toxicity, and the emergence of drug resistance. The development of inhibitors of the major T. cruzi cysteine protease, cruzain, has been demonstrated to be a promising drug discovery avenue for this neglected disease. Here we establish that a nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitor substantially ameliorates symptoms of acute Chagas disease in a mouse model with no apparent toxicity. A high-resolution crystal structure confirmed the mode of inhibition and revealed key binding interactions of this novel inhibitor class. Subsequent structure-guided optimization then resulted in inhibitor analogues with improvements in potency despite minimal or no additions in molecular weight. Evaluation of the analogues in cell culture showed enhanced activity. These results suggest that nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitors have the potential to fulfill the urgent need for improved Chagas disease chemotherapy.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
authors.forename: Katrien
authors.initials: K
authors.lastname: Brak
authors.forename: Iain D
authors.initials: ID
authors.lastname: Kerr
authors.forename: Kimberly T
authors.initials: KT
authors.lastname: Barrett
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Fuchi
authors.forename: Moumita
authors.initials: M
authors.lastname: Debnath
authors.forename: Kenny
authors.initials: K
authors.lastname: Ang
authors.forename: Juan C
authors.initials: JC
authors.lastname: Engel
authors.forename: James H
authors.initials: JH
authors.lastname: McKerrow
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Doyle
authors.forename: Linda S
authors.initials: LS
authors.lastname: Brinen
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Ellman
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D014355:Chagas Disease / Q000188:drug therapy*; D003546:Cysteine Endopeptidases; D005260:Female; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000469:parasitology; D051379:Mice; D008809:Mice, Inbred C3H; D008958:Models, Molecular; D021261:Parasitic Sensitivity Tests; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors*; D011804:Quinolines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D014344:Trypanocidal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D014349:Trypanosoma cruzi / Q000187:drug effects
chemical_list: D007659:Ketones; D015800:Protozoan Proteins; D011804:Quinolines; D014230:Triazoles; D014344:Trypanocidal Agents; D003546:Cysteine Endopeptidases; C074032:cruzain, Trypanosoma cruzi