Banca de DEFESA: GERCIANE SILVA DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : GERCIANE SILVA DE OLIVEIRA
DATE: 30/08/2022
TIME: 08:00
LOCAL: Plataforma digital GoogleMeet: https://meet.google.com/vgd-wqrn-hbe
TITLE:

EVALUATION OF THE GENOTOXICITY OF TRYPSIN INHIBITOR ISOLATED FROM TAMARIND SEED (Tamarindus indica L.) AND OF THE IN VITRO AND IN SILIUM ANTIBACTERIAL POTENTIAL OF ITS DERIVATIVE PEPTIDES

KEY WORDS:

Protease inhibitors. Antimicrobial peptides. Molecular Dynamics Simulation.

PAGES: 109
BIG AREA: Ciências da Saúde
AREA: Nutrição
SUMMARY:

Bacterial infections have become a global concern. As a result, the search for natural and safe therapeutic agents with antibacterial action, such as protease inhibitors, is increasing. In the present study, the genotoxicity of the trypsin inhibitor isolated from tamarind seeds (ITT) was evaluated and the antibacterial effect of its derived peptides was investigated in vitro and in silico. For this, initially, the ITT was obtained by trypsin-Sepharose 4B affinity chromatography and identified. Biological safety was evaluated through the cytotoxicity of ITT using the MTT method and genotoxicity using the CBMN in CHO-K1 cells, using 0.3 and 0.6 mg/mL. The ITT digestion pattern was established by means of simulated digestion and proteolytic hydrolysis in vitro, simulating the oral, gastric and intestinal phases according to the INFOGEST protocol, however, digestion fluids were not used for hydrolysis. To determine enzymatic susceptibility, the digested/hydrolyzed ITT was monitored by molecular mass analysis and inhibitory activity on trypsin. The antibacterial activity in vitro was tested for the hydrolyzed ITT. For in silico cleavage, the theoretical model of ITT, number 56, and conformation number 287 (ITTp 56/287) was used, being subjected to theoretical cleavage with the combination of trypsin and chymotrypsin (determined by simulated digestion), using the analysis tool PeptideCutter from the ExPASy server. Subsequently, to select the peptide with antibacterial potential, these were aligned with the ITTp 56/287 to identify the positions of amino acid residues using the CLUSTAL W server and after selecting the peptide with the greatest antibacterial potential, the molecular dynamics (DM ) using the GROMACS package. The ITT (0.3 and 0.6 mg/mL) did not cause cytotoxicity or genotoxicity in the cells (p<0.05), when digested/hydrolyzed in vitro, it remained intact in the oral and gastric phases, while the intestinal enzymes (trypsin and chymotrypsin) were effective in cleaving the ITT. The hydrolyzed ITT (7mg/mL) evaluated for antibacterial activity in vitro against E. faecalis, S. aureus and S. epidermidis, at the concentrations tested, did not show bacteriostatic or bactericidal activity. In silico analysis, Peptidetripchyme59 (TVSQTPIDIPIGLPVR) showed amphipathic amino acid residues, hydrophobicity 0.636 and α-helix structure. In DM, Peptidotrychyme59 showed interaction potential energy (EPI) of -518.08 kcal.mol-1 with the membrane of Gram-positive bacteria and threonine and arginine residues showed the best EPI. Therefore, the results bring new perspectives of studies and applications for ITT and its derived peptides on antibacterial activity.

 

COMMITTEE MEMBERS:
Presidente - 2578619 - ANA HELONEIDA DE ARAUJO MORAIS
Interna - 2378605 - CRISTIANE FERNANDES DE ASSIS
Externa à Instituição - RICHELE JANAINA ARAUJO MACHADO - UNICHRISTUS