Characterization of mechanism of action of cruzain inhibitors selected by virtual screening

• Grant number: 08/11138-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2009
• End date: November 30, 2011
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Antonia Tavares Do Amaral
• Grantee: Erika Piccirillo
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Proteases are enzymes present in all living organisms responsible for numerous physiological processes and therefore are interesting targets for the development of bioactive compounds. Among the proteases of interest for Chagas disease, Cruzipain, or its recombinant form called Cruzain, is recognized as one of the main target for developing new antichagasic drugs. Chagas disease is endemic in Brazil and the weak chemotherapeutic arsenal, and the limited interest in the search for new antichagasic drugs - restricted to developing countries - motivate the search for new antichagasic drugs. Recently, in a PhD thesis developed in our research group, it has been proposed, validated and then applied to the ZINC database virtual screening models for cruzain inhibitors. The application of these virtual screening models selected 55 compounds, among them 19 were purchased and tested against cruzain. It was observed that one of them, the compound MALV-01 (Table 02) presented specific inhibition with Ki = 21mM, while the other 18 showed no significant inhibition under the same experimental conditions used, until the concentration of 592 mM or, until the compounds loss their solubility. The enzymatic assays were performed in the presence of 0.1% of Triton X-100 to minimize the possibility of occurrence of enzyme inhibition through the promiscuous mechanism In this context, this project aims to identify and characterize the mechanism of action of a compound (MALV-01 - Table 02), identified as cruzain inhibitor and verify the cruzain inhibitory activity for some of the compounds selected by the virtual screening model( MALV-02 the MALV-09, Tab.02), focusing, in particular, the time dependence of inhibition. (AU)