Investigation of the relationship between the structure and function of Ts2, a neurotoxin from Tityus serrulatus venom.
FEBS J
; 279(8): 1495-504, 2012 Apr.
Article
em En
| MEDLINE
| ID: mdl-22356164
Scorpion toxins targeting voltage-gated sodium (Na(V)) channels are peptides that comprise 60-76 amino acid residues cross-linked by four disulfide bridges. These toxins can be divided in two groups (α and ß toxins), according to their binding properties and mode of action. The scorpion α-toxin Ts2, previously described as a ß-toxin, was purified from the venom of Tityus serrulatus, the most dangerous Brazilian scorpion. In this study, seven mammalian Na(V) channel isoforms (rNa(V)1.2, rNa(V)1.3, rNa(V)1.4, hNa(V)1.5, mNa(V)1.6, rNa(V)1.7 and rNa(V)1.8) and one insect Na(V) channel isoform (DmNa(V)1) were used to investigate the subtype specificity and selectivity of Ts2. The electrophysiology assays showed that Ts2 inhibits rapid inactivation of Na(V)1.2, Na(V)1.3, Na(V)1.5, Na(V)1.6 and Na(V)1.7, but does not affect Na(V)1.4, Na(V)1.8 or DmNa(V)1. Interestingly, Ts2 significantly shifts the voltage dependence of activation of Na(V)1.3 channels. The 3D structure of this toxin was modeled based on the high sequence identity (72%) shared with Ts1, another T. serrulatus toxin. The overall fold of the Ts2 model consists of three ß-strands and one α-helix, and is arranged in a triangular shape forming a cysteine-stabilized α-helix/ß-sheet (CSαß) motif.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Venenos de Escorpião
/
Canais de Sódio
/
Ativação do Canal Iônico
/
Neurotoxinas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
FEBS J
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido