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Neurochemical Research

, Volume 33, Issue 8, pp 1525–1533 | Cite as

Two Novel Ergtoxins, Blockers of K+-channels, Purified from the Mexican Scorpion Centruroides elegans elegans

  • Rita Restano-Cassulini
  • Timoteo Olamendi-Portugal
  • Fernando Zamudio
  • Baltazar Becerril
  • Lourival Domingos Possani
Original Paper

Abstract

Voltage-gated potassium channels of the ether-a-go-go related gene (ERG) family are implicated in many important cellular processes. Three such genes have been cloned (erg1, erg2 and erg3) and shown to be expressed in the central nervous system (CNS) of mammalians. This communication describes the isolation and characterization of two isoforms of scorpion toxin (CeErg4 and CeErg5, systematic nomenclature γ-KTx1.7 and γ-KTx1.8, respectively) that can discriminate the various subtypes of ERG channels of human and rat. These peptides were purified from the venom of the Mexican scorpion Centruroides elegans elegans. They contain 42 amino acid residues, tightly folded by four disulfide bridges. Both peptides block in a reversible manner human and rat ERG1 channels, but have no effect on human ERG2. They also block completely and irreversibly the rat ERG2 and the human ERG3 channels hence are excellent tools for the discrimination of the various sub-types of ion-channels studied.

Keywords

Ergtoxin ERG channel CeErg4 CeErg5 Centruroides elegans elegans Ion-channel Scorpion Potassium channel 

Notes

Acknowledgments

This work was partially supported by grants numbers: 014109 from Fondo Salud-CONACyT, 48646 SEP-CONACyT) and DGAPA-UNAM IN227507 to LDP. The authors are indebted to Profs. J. Schwarz, B. Ganetzky and A. Arcangeli for donation of the plasmids used in this work.

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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Rita Restano-Cassulini
    • 1
  • Timoteo Olamendi-Portugal
    • 1
  • Fernando Zamudio
    • 1
  • Baltazar Becerril
    • 1
  • Lourival Domingos Possani
    • 1
  1. 1.Departamento de Medicina Molecular y Bioprocesos, Instituto de BiotecnologíaUniversidad Nacional Autónoma de MéxicoCuernavacaMexico

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