Banca de DEFESA: Israel Flor Silva de Araújo

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Israel Flor Silva de Araújo
DATE: 06/07/2023
TIME: 09:00
LOCAL: Auditório 2 do IB
TITLE:

Primary structure and activity on KV and CaV channels of the TfTx peptide, isolated from the venom of the scorpion Tityus fasciolatus

KEY WORDS:

Tityus fasciolatus; Scorpion; Peptide; Neurotoxin; Ionic Channel.

PAGES: 70
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Scorpions are well-adapted arachnids and have been around for approximately 400 million years. The Buthidae family is notable for the clinical importance of its species, which possess neurotoxic venoms. In Brazil, there are over 82 species, with a focus on the genus Tityus. The venom of these scorpions contains various compounds, such as peptides, enzymes, and inorganic salts, with diverse activities under study. In the central region of Brasília, near the University of Brasília, approximately 30 specimens of both male and female Tityus fasciolatus were collected. The animals were kept alive in the Animal Facility of the Institute of Biology at the University of Brasília, and through the process of electrostimulation, 46 milligrams of crude venom were extracted. The material underwent purification through two stages of High-Performance Liquid Chromatography (HPLC) to obtain 86.2 µg of pure TfTx peptide. The neurotoxin TfTx, a peptide isolated from the venom of Tityus fasciolatus, has a molecular mass of 3,583.64 Da [M+H]+ and its sequence revealed 31 amino acid residues stabilized by four disulfide bridges. In comparisons made in databases, it was observed that this peptide has a high degree of identity with peptides acting on potassium channels, Bmkk4 isolated from Mesobuthus martensii venom and pMeKTx7 isolated from Mesobuthus eupeus venom, in addition, a high degree of identity was also observed with two other peptides: CllNtx isolated from the venom of Centruroides limpidus and 'Peptide A' isolated from Centruroides hirsutipalpus. This second group of peptides has no regulated activity, and studies carried out with these recommendations show that they comprise a not yet described family of neurotoxins with possible activity on potassium channels. This work had as main objective the elucidation of the primary structure and the evaluation of the activity of the toxin in selective ion channels for potassium (KV1.4, KV3.1 and hERG1) and selective channels for calcium (CaV1.2, CaV1.3, CaV2 1, CaV2.2 and CaV2.3), however, no significant current or voltage change was observed to determine the activity of the peptides in these channels.

COMMITTEE MEMBERS:
Interno - ***.125.178-** - AISEL VALLE GARAY - UnB
Presidente - 405268 - ELISABETH NOGUEIRA FERRONI
Externo ao Programa - 1744566 - MAURICIO HOMEM DE MELLO - nullExterna à Instituição - THALITA SOARES CAMARGOS - CMB