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OcyKTx2, a new K⁺-channel toxin characterized from the venom of the scorpion Opisthacanthus cayaporum.
- Source :
-
Peptides [Peptides] 2013 Aug; Vol. 46, pp. 40-6. Date of Electronic Publication: 2013 May 15. - Publication Year :
- 2013
-
Abstract
- 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).<br /> (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Subjects :
- Amino Acid Sequence
Animals
Cells, Cultured
Humans
Intercellular Signaling Peptides and Proteins
Peptides chemistry
Peptides isolation & purification
Potassium Channel Blockers chemistry
Potassium Channel Blockers isolation & purification
Potassium Channel Blockers metabolism
Protein Binding
Scorpion Venoms chemistry
Scorpion Venoms isolation & purification
Scorpions metabolism
Sequence Alignment
Sequence Analysis, Protein
Kv1.3 Potassium Channel antagonists & inhibitors
Peptides metabolism
Scorpion Venoms metabolism
Shaker Superfamily of Potassium Channels antagonists & inhibitors
Subjects
Details
- Language :
- English
- ISSN :
- 1873-5169
- Volume :
- 46
- Database :
- MEDLINE
- Journal :
- Peptides
- Publication Type :
- Academic Journal
- Accession number :
- 23684923
- Full Text :
- https://doi.org/10.1016/j.peptides.2013.04.021