MODULATION BY HEPARIN OF THE INHIBITORY ACTIVITY OF COMPOUNDS DERIVED FROM CHALCONES, FLAVONOIDS, PALLADIUM COMPLEXES AND AMINOTHIAZOLE ON CATHEPSINS B AND L

• Grant number: 25/02023-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Biochemistry - Enzymology
• Principal Investigator: Wagner Alves de Souza Júdice
• Grantee: Maria Luiza Gonçalves Gallego Rosa
• Host Institution: Pró-Reitoria Acadêmica. Universidade de Mogi das Cruzes (UMC). Campus da Sede Mogi das Cruzes. Mogi das Cruzes , SP, Brazil

Abstract

This research project aims to investigate the influence of heparin on the inhibition of cathepsins B and L by various compounds, including chalcone derivatives, flavonoids, palladium complexes, and aminothiazoles. These proteolytic enzymes play critical roles in protein degradation and cellular regulation and are frequently implicated in the progression of diseases such as cancer. Under pathological conditions, their activity may become dysregulated, promoting cell proliferation, tissue invasion, and metastasis. Consequently, selective inhibition of these enzymes represents a promising strategy for developing novel therapeutic approaches. The presence of glycosaminoglycans (GAGs), such as heparin, can significantly impact the efficacy of enzyme inhibitors, highlighting the need for a detailed understanding of this interaction. Studies indicate that heparin can modulate cathepsin activity by enhancing cathepsin B function, accelerating cathepsin L inhibition, and stabilizing their structure under alkaline conditions. Additionally, GAGs play a key role in the activation of extracellular cathepsins in various pathological contexts, reinforcing the importance of evaluating how heparin affects the inhibition of these enzymes by different compounds. This study aims to elucidate the inhibition mechanisms of cathepsins B and L in the presence of heparin by determining kinetic parameters (Ki, ¿Ki, kcat, Km, and kcat/Km) at different pH values. Furthermore, it seeks to optimize the expression and purification of these enzymes. Enzymatic assays will be conducted using spectrofluorimetry, incubating cathepsins with varying concentrations of inhibitors in the presence or absence of heparin. Data analysis will be performed using the Grafit® 5.0.13 software to assess the impact of pH on enzymatic activity and inhibitor efficacy.