| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1162-2 | ||||
Resumo:Tuberculosis (TB) remains a formidable challenge in the global health landscape, standing out as one of the most lethal infectious diseases caused by a single pathogen. The effective treatment of TB is hindered by several factors, primarily due to poor adherence and completion of treatments. This is largely attributed to their prolonged duration and significant side effects. In this context, Plectasin, a fungal defensin isolated from Pseudopectania nigrella, presents a new ray of hope. This compound has demonstrated its efficacy against strains of Mycobacterium tuberculosis (MTB) as well as multi-drug-resistant MTB strains. The primary aim of this research was to develop more compact and potent analogs of Plectasin's antimicrobial peptide (AMP) that could eradicate MTB without causing adverse effects. To achieve this, the original AMP sequence, composed of 40 amino acids arranged in a beta-sheet and an alpha-helix, was fragmented. Through machine-learning-based bioinformatic analysis, it was determined that the anti-MTB activity resided in the beta-sheet. From this insight, permutations in the cysteines and glycines of the beta-sheet were executed, resulting in a library of 1,102 AMP analogs. Using bioinformatics techniques, we selected the four most promising analogs. This selection was based on their in silico antimycobacterial activity (AntiTbPpred), pharmacokinetic properties (pkCSM), half-life (plifepred), and was concluded with molecular docking assays between receptors and the AMP analogs (Vina). Subsequently, the four most promising analogs were synthesized using the F-moc solid-phase synthesis method. The synthesized products were subjected to LC/MS analysis and were purified with HPLC. Cytotoxicity assays were then conducted on MRC-5 lung fibroblasts, J774A.1 macrophages, and Caco-2 cells. The minimum inhibitory concentrations were determined using the resazurin microtiter assay on the H37Rv strain. Additionally, ethidium bromide accumulation assays were conducted to evaluate the AMPs' ability to inhibit efflux pumps. The results revealed a potent anti-MTB activity of AMPs DC05 and DC10. Furthermore, all AMPs did not induce cytotoxicity in any of the cell lines, even at concentrations exceeding 500 µM. The peptides DC08 and DC10 were found to be more efficient in inhibiting efflux pumps than the control drug, Verapamil, suggesting their potential against resistant MTB strains. This research underscores the potential of bioinformatic tools in the identification and development of new drugs, allowing for a significant reduction in costs and time in the drug discovery process. Palavras-chave: Tuberculosis, Antimicrobial peptide, Bioinformatic, Drug discovery Agência de fomento:CAPES | |||||