Synthesis and pharmacological evaluation of modulatory compounds for the caseinolytic proteases (ClpP1P2) of Mycobacterium tuberculosis and their application in the BacPROTAC strategy

• Grant number: 24/03928-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: January 01, 2025
• End date: July 31, 2028
• Field of knowledge: Health Sciences - Pharmacy
• Principal Investigator: Jean Leandro dos Santos
• Grantee: Andressa Francielli Bonjorno
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb), which still poses a significant challenge to Public Health, mainly due to the emergence of multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) strains. According to the World Health Organization (WHO), in 2022, approximately 7.5 million new cases of TB were diagnosed, with 1.3 million deaths attributed to the disease. Among these cases, 410,000 patients had multidrug-resistant TB (MDR-TB) or extensively drug-resistant TB (XDR-TB). The search for new drugs constitutes one of the pillars established by the WHO to mitigate the disease. Among the potentially promising targets present in Mtb, the caseinolytic proteases (Clp) play a crucial role in the ubiquitination system of mycobacteria, promoting protein degradation by the bacillus. By exploiting the planning strategy called BacPROTACs, new ligands of mycobacterial Clp will be developed to target the selective degradation of a specific protein of interest (PI). Nitroreductases (NRTs) are enzymes present in Mtb that appear to be associated with the anaerobic metabolism of non-replicating bacilli. Studies by our research group have shown the potent anti-Mtb effect of NTR ligands (delamanid and pretomanid), under conditions simulating the intramacrophage dormancy state. Thus, we hypothesize that the degradation of NTRs by exploiting the BacPROTAC strategy could lead to more effective and safer compounds, due to a potential selective effect against Mtb. This project aims to develop new Clp ligands, conjugated with NTR ligands planned from the structure of delamanid, with the aim of disrupting the survival mechanisms used by Mtb, and presenting effects against MDR-TB, XDR-TB strains, and activity in dormant bacilli. The planned compounds will be synthesized and characterized by analytical methods, and the evaluation of derivatives through phenotypic screening will be assessed against MTB H37Rv strains and clinical isolates of MDR-TB and XDR-TB. Additionally, assays to evaluate mutagenicity, genotoxicity, activity against NTR, and Clp will be conducted. Finally, it is expected that this study will identify new drug candidates that could act as an alternative to the treatment of multidrug-resistant TB, improving the current treatment.