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OcyKTx2, a new K⁺-channel toxin characterized from the venom of the scorpion Opisthacanthus cayaporum.
Schwartz, Elisabeth F; Bartok, Adam; Schwartz, Carlos Alberto; Papp, Ferenc; Gómez-Lagunas, Froylan; Panyi, Gyorgy; Possani, Lourival D.
Afiliação
  • Schwartz EF; Department of Physiological Sciences, Institute of Biological Sciences, University of Brasilia, Brasilia, 70910-900 DF, Brazil. efschwa@unb.br
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 K⁺-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 K⁺-channels with a Kd of 82 nM, and presents an even better affinity toward hKv1.3, blocking it with a Kd of ∼18 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).
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Peptídeos / Venenos de Escorpião / Superfamília Shaker de Canais de Potássio / 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

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Peptídeos / Venenos de Escorpião / Superfamília Shaker de Canais de Potássio / 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