title: Divergent modes of enzyme inhibition in a homologous structure-activity series.
abstract: A docking screen identified reversible, noncovalent inhibitors (e.g., 1) of the parasite cysteine protease cruzain. Chemical optimization of 1 led to a series of oxadiazoles possessing interpretable SAR and potencies as much as 500-fold greater than 1. Detailed investigation of the SAR series subsequently revealed that many members of the oxadiazole class (and surprisingly also 1) act via divergent modes of inhibition (competitive or via colloidal aggregation) depending on the assay conditions employed.
authors.affiliation: Small Molecule Discovery Center, Sandler Center for Basic Research in Parasitic Diseases, and Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th Street, San Francisco, CA 94158, USA.
authors.forename: Rafaela S
authors.initials: RS
authors.lastname: Ferreira
authors.forename: Clifford
authors.initials: C
authors.lastname: Bryant
authors.forename: Kenny K H
authors.initials: KK
authors.lastname: Ang
authors.forename: James H
authors.initials: JH
authors.lastname: McKerrow
authors.forename: Brian K
authors.initials: BK
authors.lastname: Shoichet
authors.forename: Adam R
authors.initials: AR
authors.lastname: Renslo
mesh_terms: D003102:Colloids; D003546:Cysteine Endopeptidases / Q000737:chemistry; D015853:Cysteine Proteinase Inhibitors / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D016208:Databases, Factual; D006016:Glycolates / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D008958:Models, Molecular; D010069:Oxadiazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D021261:Parasitic Sensitivity Tests; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D013329:Structure-Activity Relationship; D014344:Trypanocidal Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D014349:Trypanosoma cruzi / Q000187:drug effects* / Q000201:enzymology
chemical_list: D003102:Colloids; D015853:Cysteine Proteinase Inhibitors; D006016:Glycolates; D010069:Oxadiazoles; D015800:Protozoan Proteins; D014344:Trypanocidal Agents; D003546:Cysteine Endopeptidases; C074032:cruzain, Trypanosoma cruzi