MINERAÇÃO DE UM PEPTÍDEO COM POTENCIAL ANTIMICROBIANO E ANTICÂNCER A PARTIR DA SEQUÊNCIA DO INIBIDOR DE TRIPSINA DE Inga laurina (ILTI)

Abstract

Antimicrobial resistance represents a serious threat to public health, necessitating the urgent development of effective therapeutic alternatives. Among emerging approaches, antimicrobial peptides (AMPs) are particularly promising due to their low propensity to induce resistance, attributed to their direct mechanism of action on the cell membrane, as well as the high efficacy rates observed. This study aimed to develop a peptide with both antimicrobial and anticancer activity, employing computational tools to guide its design and evaluate its activity, toxicity, and structural conformation. The process began with the segmentation and prediction of the amino acid sequence of the ILTI (Inga laurina trypsin inhibitor) protein, using the CAMPR3, NEPTUNE, Sense the Moment, ACPred, AntiCP, Happenn, Ennact, and ToxinPred servers. The top-performing sequence, designated GWA-18, was further refined using the Joker algorithm, which rearranged hydrophobic and hydrophilic residues to generate the bioinspired peptide GWA-17. Following synthesis, the secondary structure of GWA-17 was characterized by circular dichroism, revealing an α-helical conformation in the presence of 50% trifluoroethanol and SDS. Antimicrobial activity was determined using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays, while cell viability was assessed in BV-2 microglia cells and the tumor cell lines HeLa, B16F10-nex2, SK-mel-28, and A375. GWA-17 demonstrated significant antimicrobial activity, with MIC and MBC values ranging from 4 to 64 μM. Notably, Escherichia coli and Staphylococcus epidermidis exhibited MIC values of 4 μM and 16 μM, respectively. A membrane permeability assay, using the Sytox™ Green fluorescent probe, confirmed that GWA-17 disrupts the bacterial membrane, with noticeable effects within the first 5 minutes of incubation, suggesting a rapid and effective mechanism of action. In cell viability assays, GWA-17 reduced the viability of the tested cancer cell lines, with IC50 values of 21.63 μM for B16F10-nex2, 30.28 μM for HeLa, 51.59 μM for SK-mel-28, and 29.57 μM for A375, inducing apoptotic cell death. Additionally, IC50 values of 31.57 μM for FN1 and 32.72 μM for normal BV-2 cells were observed. Furthermore, GWA-17 exhibited a favorable safety profile, displaying minimal hemolytic activity up to 50 μM, a concentration exceeding the therapeutic range established in previous assays. These findings highlight GWA-17 as a promising bifunctional candidate, exhibiting both antibacterial and anticancer activity, particularly in resistance scenarios, with potential clinical applications in infectious disease control and cancer therapy.