Banca de DEFESA: ELLYNES AMANCIO CORREIA NUNES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ELLYNES AMANCIO CORREIA NUNES
DATE: 15/10/2024
TIME: 15:00
LOCAL: Videoconferência - Link para acesso: https://meet.google.com/krm-hkji-tes
TITLE:

PURIFICATION, CHARACTERIZATION AND BACTERIOSTATIC ACTIVITY OF A MANGANESE-DEPENDENT LECTIN FROM THE VENOM OF Bothrops moojeni

KEY WORDS:

 

Biological activity. Snake venoms. Bioprospecting.

PAGES: 97
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

Bioactive molecules isolated from venomous animals constitute a variety of components with biological activities that can be directed to the treatment of different diseases. Snake venoms are composed of approximately 90% proteins and peptides. These toxins perform different biochemical mechanisms and are therefore responsible for the clinical response observed in snakebites. Knowledge of snake proteins allows the study of heterologous activities related to these toxins, such as antibacterial and antitumor activity. In this context, the objective of this study was to conduct a bibliographic review on the protein group of lectins isolated from snake venoms and to isolate, characterize and understand the biological activities of a lectin from the venom of the snake Bothrops moojeni. A literature review was conducted on lectins isolated and characterized from snake venoms, focusing on their main characteristics and classification, with an emphasis on studies from the last decade. It was found that, to date, snake venom lectins are predominantly classified as C-type lectins and C-type lectin-like proteins, exhibiting diverse biological activities. These include potential applications in the treatment of neoplastic and hematologic diseases, as well as demonstrated antibacterial properties. In addition, the identification of a protein with lectin activity was performed using Size Exclusion Chromatography (SEM) and Reverse-Phase High Performance Liquid Chromatography (RP-HPLC). The following procedures included analysis by Polyacrylamide Gel (SDS-PAGE), as well as hemagglutination assays, inhibition of hemagglutinating activity, and evaluation of ion, pH and temperature dependence. Additionally, hemolytic activity, antibacterial activity against the bacterial strains Acinetobacter baumannii and Staphylococcus aureus, and antibiofilm activity was evaluated. Molecular exclusion generated a chromatographic profile with 6 peaks that were analyzed by polyacrylamide gel electrophoresis and subjected to hemagglutination assays. Hemagglutinating activity was observed in fractions 5 and 6, with the best result for fraction 5, which was named BmoojL. It was also confirmed that BmoojL is manganese-dependent. Furthermore, BmoojL was inhibited in the presence of the carbohydrate’s glucose, fructose, mannose, fucose and N-acetylgalactosamine, and was active at temperatures up to 80 °C and in pH ranges from 5 to 9. The hemolytic assay showed that the molecule did not promote hemagglutination at the concentrations tested (31.25 - 500 µg. mL-1), with a hemolysis percentage below 10%. The antibacterial assays showed that despite not reaching the minimum inhibitory concentration, BmoojL reduced the bacterial growth of A. baumannii from the concentration of 64 µg. mL-1. The antibiofilm assay showed that for S. aureus, BmoojL was effective, considerably reducing biofilm growth at all concentrations tested (16 - 512 µg. mL-1) by approximately 50%. It was also shown that the ion, in isolation and associated with another protein, did not perform significant activity, as observed with BmoojL. Furthermore, it was found that BmoojL inhibited bacterial growth, indicating that the molecule acts bacteriostatically. Thus, the study allowed the isolation of a molecule with manganese-dependent lectin activity with the potential to exert antibacterial and antibiofilm activity, contributing to the research of bioactive molecules derived from venomous snakes. Although the literature recommends some studies involving such molecules and their heterologous activity, when compared to other molecular groups, the study involving lectins from venomous animals remain an underexplored area of research. These findings show what there is still to know about these molecules and to direct and propose new activities that may add to biotechnological research involving these animal groups.

COMMITTEE MEMBERS:
Presidente - ***.121.724-** - LUDOVICO MIGLIOLO - UCDB
Interna - 1549705 - ADRIANA FERREIRA UCHOA
Interno - 1149356 - ELIZEU ANTUNES DOS SANTOS
Externa à Instituição - JULIANA PAVAN ZULIANI - UNIR
Externo à Instituição - OCTÁVIO LUIZ FRANCO - UCDB