Banca de DEFESA: RODRIGO DE PAULO OSORIO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RODRIGO DE PAULO OSORIO
DATE: 28/09/2021
TIME: 09:30
LOCAL: google meet
TITLE:

Analysis of the relationship between the antioxidant potential of ferulic and p-coumaric acids and the catalase enzyme from Saccharomyces cerevisiae.

KEY WORDS:

Oxidative stress, phenolic acids, catalase, Saccharomyces cerevisiae.

PAGES: 72
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Bioquímica dos Microorganismos
SUMMARY:

Oxidative stress is a condition generated by the inability of the antioxidant defense system to control the action of oxidants in cells, which can react with lipids, proteins and DNA, damaging the properties of cells structures. Oxidative stress has been associated with several pathologies, such as neurodegenerative diseases, diabetes and cancer. Ferulic and p-coumaric acids are exogenous antioxidants related to positive effects against neurodegenerative diseases. However, it is important to understand better the action mechanisms of these compounds. Thus, cell viability, catalase activity, antioxidant activity and molecular modeling experiments were carried out in order to analyze the relationship between the antioxidant potential of ferulic and p-coumaric acids and the catalase enzyme from Saccharomyces cerevisiae. Both acids did not show toxicity at the concentration of 10 µg.mL^-1 for cells. The analysis of the effect of these acids on catalase activity under different concentrations of hydrogen peroxide (0,0 mM, 0,5 mM and 2,5 mM) revealed catalase activity of 77,76% and 53,63%; 127,52% and 104,39%; and 83,67% and 70,61% for ferulic and p-coumaric acids in relation to the negative control, respectively. Regarding the antioxidant potential, pretreatment with acids showed an increase in cell viability after oxidative stress with hydrogen peroxide (2,0 mM). These results were observed in the BY4741 control (greater than 20% increase) and the catalase deficient Δctt1 strain mutant (greater than 25% increase). Analyzing by molecular docking (GOLD), it was found that possibly the amino acid residues Val111, Pro124, Phe148, Phe149 and Phe159 are important for the interactions of both phenolic acids with the enzyme. By allowing the flexibility of the side chains with amino acid residues Val111, Phe148, Phe149, Phe156, Phe159 and Ile160, the scores for phenolic acids are high, with an emphasis on the side chain of residue Phe159. In conclusion, ferulic acid and p-coumaric acid provide cellular protection against oxidative stress and this protection is apparently unrelated to their direct effect on catalase.

BANKING MEMBERS:
Presidente - 1844240 - CRISTIANO JORGE RIGER
Interno - 1700480 - ARTHUR EUGEN KUMMERLE
Interna - 1681790 - CRISTIANE MARTINS CARDOSO DE SALLES
Externa à Instituição - JOELMA FREIRE DE MESQUITA - UNIRIO
Externa à Instituição - CARMELITA GOMES DA SILVA - IFRJ