Banca de DEFESA: CLAUDIA SIQUEIRA DE OLIVEIRA
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.DISCENTE : CLAUDIA SIQUEIRA DE OLIVEIRA
DATA : 19/03/2020
HORA: 09:00
LOCAL: programa de Biologia Experimental
TÍTULO:
Assessment of biological effects induced by marine extracts and investigation of the antimicrobial potential of synthetic peptides obtained from anemone phospholipase A2 Condylacts giganteaPALAVRAS-CHAVES:
Keywords: Marine invertebrate, Condylactis gigantea, phospholipase, antimicrobial.
PÁGINAS: 90
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:
Microbial resistance is a phenomenon developed by several microorganisms including bacteria, fungi, viruses and parasites. Infections caused by microorganisms resistance are generally at increased risk of worse clinical outcomes, death and increases cost health-care. The situation is reported worldwide, it is considered as an emerging global public health problem. Researchers, doctors and professionals in the field to invest in alternatives for the development of new drugs. In this context, studies involving marine invertebrates, as sources of bioactive molecules against pathogenic microorganisms is a line of research that has gained prominence today due to the success with the results obtained. This work we evaluate the biological effects induced by extracts from anemone Condylactis gigantea (CgTotal and CgPede) and investigate the antimicrobial potential of synthetic peptides obtained from phospholipase A2 called CgPLA2. The extracts were evaluated in vitro for the ability to produce hemolysis and cleave fluorescent phospholipids and in vivo for the ability to induce edema and myotoxicity. Cytotoxicity was observed using human tumor cell lines Jurkat (leukemia T) and B16F10 (melanoma). And the antimicrobial investigation was carried out against strains of E. faecalis (Van-A), E. faecalis (Van-B), S. aureus (MRSA) and K. peneumonie multiresistant. The search for epitopes in the CgPLA2 amino acid sequence was performed by comparing similarity between the phospholipase and bioactive peptide sequences deposited in the database. The CgTotal extract was fractionated by molecular exclusion chromatography, followed by ion exchange chromatography and reverse phase in a C18 column. The phospholipase activity of the fraction of interest and isolated molecule was identified by the hydrolysis of 4N3OBA acid. The results showed that CgTotal did not produce hemolysis, did not show phospholipase activity against the fluorescent substrate, did not show to be edematogenic, myotoxic or cytotoxic. CgParede, did not produce indirect hemolysis, did not show phospholipase activity, did not produce edema and myotoxicity, and was not cytotoxic against the B16F10 cell, but produced direct hemolysis and cytotoxicity on the Jurkat cell. Fractionation was efficient for the isolation of an acid molecule with phospholipase activity. Screening for epitopes with antimicrobial activity from the CgPLA2 sequence resulted in three synthetic peptides that did not show toxicity against the tested bacterial strains. The results obtained with this work, demonstrate that the extract of the anemone C. gigantea can be an interesting object of study to explore the cytotoxic potential on tumor cells. The fragments of the phospholipase expressed in this organism, can serve as inspiration for the rational design of synthetic peptides to be prospected against bacterial strains.
MEMBROS DA BANCA:
Externo ao Programa - 1530806 - ALEXANDRE DE ALMEIDA E SILVA
Externo à Instituição - CAROLINA BIONE GARCIA TELES - FIOCRUZ
Externo à Instituição - CESAR LUIZ DA SILVA GUIMARAES - FIOCRUZ
Presidente - 1522184 - LEONARDO DE AZEVEDO CALDERON
Externo ao Programa - 1523620 - RUBIANI DE CASSIA PAGOTTO