OcyKTx2, a new Kâº-channel toxin characterized from the venom of the scorpion Opisthacanthus cayaporum.
Peptides
; 46: 40-6, 2013 Aug.
Article
em En
| MEDLINE
| ID: mdl-23684923
Opisthacanthus cayaporum belongs to the Liochelidae family, and the scorpions from this genus occur in southern Africa, Central America and South America and, therefore, can be considered a true Gondwana heritage. In this communication, the isolation, primary structure characterization, and Kâº-channel blocking activity of new peptide from this scorpion venom are reported. OcyKTx2 is a 34 amino acid long peptide with four disulfide bridges and molecular mass of 3807 Da. Electrophysiological assays conducted with pure OcyKTx2 showed that this toxin reversibly blocks Shaker B Kâº-channels with a Kd of 82 nM, and presents an even better affinity toward hKv1.3, blocking it with a Kd of â¼18 nM. OcyKTx2 shares high sequence identity with peptides belonging to subfamily 6 of α-KTxs that clustered very closely in the phylogenetic tree included here. Sequence comparison, chain length and number of disulfide bridges analysis classify OcyKTx2 into subfamily 6 of the α-KTx scorpion toxins (systematic name, α-KTx6.17).
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
/
Venenos de Escorpião
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Superfamília Shaker de Canais de Potássio
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Canal de Potássio Kv1.3
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Peptides
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos