Screening and Identification of Metacaspase Inhibitors: Evaluation of Inhibition Mechanism and Trypanocidal Activity
| Autor: | Fernán Agüero, Brian Pérez, Vanina E. Alvarez, Emir Salas-Sarduy, Juan José Cazzulo, León A. Bouvier |
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| Rok vydání: | 2020 |
| Předmět: |
Proteases
Trypanosoma cruzi Plasmodium falciparum Trypanosoma brucei brucei Trypanosoma brucei 03 medical and health sciences parasitic diseases Chlorocebus aethiops medicine Animals Humans Pharmacology (medical) Chagas Disease Vero Cells Mechanisms of Action: Physiological Effects 030304 developmental biology Pharmacology chemistry.chemical_classification 0303 health sciences Virtual screening biology 030302 biochemistry & molecular biology biology.organism_classification Antiparasitic agent Trypanocidal Agents Metacaspase Infectious Diseases Enzyme chemistry Mechanism of action Biochemistry medicine.symptom |
| Zdroj: | Antimicrob Agents Chemother |
| ISSN: | 1098-6596 |
| Popis: | A common strategy to identify new antiparasitic agents is the targeting of proteases, due to their essential contributions to parasite growth and development. Metacaspases (MCAs) are cysteine proteases present in fungi, protozoa, and plants. These enzymes, which are associated with crucial cellular events in trypanosomes, are absent in the human host, thus arising as attractive drug targets. To find new MCA inhibitors with trypanocidal activity, we adapted a continuous fluorescence enzymatic assay to a medium-throughput format and carried out screening of different compound collections, followed by the construction of dose-response curves for the most promising hits. We used MCA5 from Trypanosoma brucei (TbMCA5) as a model for the identification of inhibitors from the GlaxoSmithKline HAT and CHAGAS chemical boxes. We also assessed a third collection of nine compounds from the Maybridge database that had been identified by virtual screening as potential inhibitors of the cysteine peptidase falcipain-2 (clan CA) from Plasmodium falciparum. Compound HTS01959 (from the Maybridge collection) was the most potent inhibitor, with a 50% inhibitory concentration (IC50) of 14.39 µM; it also inhibited other MCAs from T. brucei and Trypanosoma cruzi (TbMCA2, 4.14 µM; TbMCA3, 5.04 µM; TcMCA5, 151 µM). HTS01959 behaved as a reversible, slow-binding, and noncompetitive inhibitor of TbMCA2, with a mechanism of action that included redox components. Importantly, HTS01959 displayed trypanocidal activity against bloodstream forms of T. brucei and trypomastigote forms of T. cruzi, without cytotoxic effects on Vero cells. Thus, HTS01959 is a promising starting point to develop more specific and potent chemical structures to target MCAs. |
| Databáze: | OpenAIRE |
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