Banca de QUALIFICAÇÃO: Luis Felipe Santos Menezes

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Luis Felipe Santos Menezes
DATE: 09/12/2022
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Effects of epilepsy-associated mutations (I1596S, V1627M and L1650P) on human Nav1.2 channel functioning and the electrophysiological characterization of the Tst2 peptide, a Nav channel modulator isolated from the scorpion Tityus stigmurus.

KEY WORDS:

Epilepsy, voltage-gated sodium channel, patch-clamp, scorpion toxin and channelopathies.

PAGES: 75
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Epilepsy is a disease caused by exaggerated activity of neurons or abnormal brain synchrony. It can be focal, generalized, or unknown. Infections (viral or bacterial in the brain), autoimmune diseases, acquired causes, and genetic mutations are the main causes. Among those caused by mutations, we can highlight mutations in voltage-gated ion channels (Na+ , K+ , Ca2+ and Cl- ). In literature, it can cite studies relating epilepsy and mutations in voltage-gated sodium channels, as a family with benign familial neonatal-infantile seizures (BFNIS) which after genetics analyses identified the presence of I1596S mutation. The study reporting the V1627M mutations that is associated with epilepsy of infancy with migrating focal seizures (EIMFS). Finally, a study reporting a patient with a mutation in the SCN2A gene (L1650P) described related to early childhood epileptic encephalopathy (EIEE). Part of the population with epilepsy is resistant to the action of drugs. It is necessary to search for new ways of treating the disease, with natural products, such as compounds of scorpion’s venom. The objective of this project is evaluate the effects of epilepsy-associated mutations (I1596S, V1627M and L1650P) on human Nav1.2 channel functioning and the electrophysiological characterization of the Tst2 peptide from the Tityus stigmurus scorpion. The purification and identification of the peptide was done by HPLC and MALDI-TOF/TOF. The mutation will be performed by the directed mutagenesis system QuikChange II (Agilent Technologies) and the electrophysiological recordings are being made in whole-cell mode, using the EPC 10 Heka amplifier through the PatchMaster software. The purification occurred in three steps, the toxin eluted at 37,8% on crude venom chromatography and the monoisotopic mass (MALDI-TOF/TOF) was [M+H]+ 6985,74 Da. Electrophysiological characterization (Nav1.1-Nav1.7) of the peptide (100 nM) was made. For activation, the most affected channel was Nav1.1 (with prepulse) and Nav1.7 (without prepulse). Nav1.3 was the most affected in inactivation and Nav1.4 for recovery from inactivation. No change in the rapid inactivation was observed. Next steps: partial sequencing of the peptide, carry out the mutations in Nav1.2, and analyzing them electrophysiologically.

BANKING MEMBERS:
Externa à Instituição - LUCIANA MIDORI INUZUKA NAKAHARADA - SÍRIO
Externa à Instituição - CAROLINE BARBOSA FARIAS MOURAO - IFB
Externa à Instituição - LILIAN DOS ANJOS CARNEIRO - UNIEURO
Presidente - 1666182 - WERNER LEOPOLDO TREPTOW