Banca de QUALIFICAÇÃO: PRISCILLA OLIVEIRA GIL

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : PRISCILLA OLIVEIRA GIL
DATE: 31/05/2022
TIME: 13:30
LOCAL: meet.google.com/gmi-gyvi-tsh
TITLE:

ENTEROCIN B: EXPRESSION, PURIFICATION, CHARACTERIZATION AND ANALYSIS OF ITS FUNGICIDAL EFFECT ON CANDIDA sp.

KEY WORDS:

 Enterocin B, Bioinformatic, Cancer, Candidiasis.

PAGES: 62
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

Enterococcus are gram-positive, non-spore-forming bacteria found in the gastrointestinal tract, widely used as probiotics and in the production of fermented foods. Previous studies have shown that enterocins found in these microorganisms might exert antitumor, antimicrobial, anticandida and antioxidant activities, among others. Enterocin B, synthesized by E. faecium, is one important IIc subclass of bacteriocins, which has already shown to be effective against pathogenic bacteria, viruses and tumor cells. The present study aims the heterologous expression of enterocin B in E. coli cells, the purification through an affinity column, the characterization from bioinformatics tools and the evaluation of its antitumor and antifungal effect in A549 lung carcinoma cells and Candida sp. strains, respectively. The results obtained from the bioinformatics analysis show that the peptide sequence has 53 amino acids, a theoretical pI of 9.25, a molecular weight of 5.4 kDa, and that it undergoes glycosylation at serine position 17 and 50, and phosphorylation at serine position 17. Its cellular localization is cytoplasmatic, it is soluble and has no signal peptide in the analyzed sequence. It has 18 hydrophobic amino acids, 18 hydrophilic amino acids, 7 positive and 3 negative. The predicted function analyzed by the InterPro program was not found, probably due to the lack of deposit of its functions in the database. The genomic analysis suggested that among the 74 Enterococcus genomes deposited in NCBI, the peptide sequence of enterocin B was only found in E. faecium and E. mundtii strains. In the in vitro assays it was possible to observe that the peptide was expressed fully in the form of inclusion bodies in E. coli BL-21 cells at 37 °C and only partially soluble using E. coli ArcticExpress cells at 16 °C. Purification occurred favorably when using 30 mM and 500 mM imidazole in the wash and elution, respectively.  Further experiments of this work are still necessary to conclude the antitumor and antifungal action of enterocin B.

BANKING MEMBERS:
Interna - 1716846 - VANESSA FARIA CORTES
Externo à Instituição - LEONARDO VAZQUEZ - UIUC
Externa à Instituição - SIMONE DA FONSECA PIRES - IFSUDESTEMG