Banca de QUALIFICAÇÃO: JOELTON IGOR OLIVEIRA DA CRUZ

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : JOELTON IGOR OLIVEIRA DA CRUZ
DATE: 05/09/2022
TIME: 09:00
LOCAL: Plataforma Google Meet (defesa remota)
TITLE:

STRUCTURAL AND FUNCTIONAL ASPECTS RELATED TO AN ISOLATED PROTEASE INHIBITOR AND FRACTIONS OBTAINED FROM Poincianella pyramidalis (Tul.) SEEDS.

KEY WORDS:

Poincianella pyramidalis, antibacterial, modulation, coagulation, inflammation

PAGES: 65
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

Plants are subject to a diversity of unfavorable biotic and abiotic conditions, constantly undergoing some evolutionary adaptation that can favor their reproduction and survival. The elaboration of sophisticated defense strategies against pests and pathogens, includes the synthesis of several natural bioactive compounds such as protease inhibitors, which stand out as part of this adaptive biological arsenal and are widely used in the most diverse lines of research. In this theme, this work aimed to evaluate the crude extract and fractions, as well as the isolated inhibitor, obtained from the seed Poincianella pyramidalis (Tul.) regarding the antielastic, anticoagulant, antibacterial and antibiotic modulating activities. The isolated inhibitor (named PpTI) was able to reduce 50% of the activities of trypsin, human neutrophil elastase (ENL) and chymotrypsin enzymes at concentrations of 0.017, 0.021 and 0.156 µg/µL, respectively. Its antitrypsin activity was maintained at high temperatures (80 ºC) and a wide pH range (2 to 12). In the in vitro assays, PpTI proved to be able to prolong the clotting time by more than 80 seconds for the intrinsic pathway (TPPa) at a concentration of 20 µg/mL. It was also observed that PpTI does not have antimicrobial activity for the tested strains ATCC Escherichia coli, ATCC Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA). The protein extracts were obtained from extraction with 0.05M Tris-HCL buffer pH 7.5 and subsequent fractionation with ammonium sulfate in different saturation ranges 0-30%, 30-60% and 60-90% of sodium sulfate ammonium. The electrophoretic profile revealed several protein bands between 12 KDa and 225 KDa. The  ntimicrobial activity was performed using the microdilution assay and the modulatory action of the antibiotics ampicillin, norfloxacin and gentamicin were determined using a MIC/8 subinhibitory concentration. It was observed that at a concentration of 128 µg/mL the samples associated with the different antibiotics (aminoglycoside, β-lactam and fluoroquinolone) had a synergistic action against the multidrug-resistant strains of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus at a significance level of p < 0.0001. The samples were able to inhibit the action of the serine protease tested in percentages above 80%. In this way, the success of this study may allow for a better effectiveness and reduction in the cost of treatment and the development of new tools to combat inflammation and clotting disorders, as well as infections caused by resistant bacteria.

COMMITTEE MEMBERS:
Externo à Instituição - FRANCISCO ELICLECIO RODRIGUES DA SILVA
Externo à Instituição - ANDERSON FELIPE JÁCOME DE FRANÇA - UFRN
Externa à Instituição - PAULA IVANI MEDEIROS DOS SANTOS - IFRN