Priorização de proteínas quinases de Trypanosoma cruzi como potenciais alvos terapêuticos para o desenvolvimento de inibidores covalentes

Abstract

Chagas disease, a neglected tropical disease caused by the organism Trypanosoma cruzi (T. cruzi), continues having a major impact on public health and financial losses, even more than 100 years after its discovery. The treatment available today has low efficacy and causes severe side effects. As an effort to combat this disease, some therapeutic targets have been explored. T. cruzi has 190 protein kinases (PKs) in its genome that act in several physiological processes, thus constituting a potential source of therapeutic targets. The knowledge about kinase structures and the studies mapping reactive cysteine residues allow the rational design of covalent inhibitors for these proteins as a strategy that balances selectivity, efficacy, and safety. In this work, we used bioinformatics techniques to prioritize T. cruzi kinases that are potentially vital to the organism and promising targets for covalent inhibition. For that, we started with a database survey of the kinases of the Dm28c 2014 (171 PKs) and CL Brener Esmeraldo-like (175 PKs) strains, followed by the classification of the kinases in their typical groups and families. Then, we mapped the cysteines present in the active site of the kinases of the two strains. We mapped twenty-five strategic positions with stereochemical and electrostatic characteristics favorable for covalent inhibition. In addition, studies that validated the biological importance of T. brucei’s kinases in vivo, in proliferation, in the cell cycle, and in the survival of the parasite, supported the PKs prioritization. In this step, focused on the CL Brener strain, we prioritized three T. cruzi kinases: AUK1, CLK1 and CRK9. AUK1 is reported to have a role in cell division and, possibly, in parasite differentiation. We believe that CLK1 and CRK9 participate in cell division based on studies in T. brucei. In addition, CRK9 would also be involved in gene expression. Finally, to enable studies on the inhibition of these kinases, we built three-dimensional models employing comparative modeling, with subsequent stereochemical and energetic validation of the models generated. The information and discussions built throughout this study on T. cruzi protein kinases can support new proposals for therapeutic targets and bring new perspectives to the management of Chagas disease.