Charybdotoxin blocks both Ca-activated K channels and Ca-independent voltage-gated K channels in rat brain synaptosomes

FEBS Lett. 1989 Jul 3;250(2):433-6. doi: 10.1016/0014-5793(89)80771-9.

Abstract

Charybdotoxin (ChTX), a 4.3 kDa polypeptide toxin from the venom of the scorpion Leiurus quinquestriatus, blocks both a Ca-activated K channel (IC50 approximately 15 nM) and a Ca-independent voltage-gated K channel (IC50 approximately 40 nM) in rat brain synaptosomes. These results indicate that in this preparation ChTX is not specific for the Ca-activated K channel and suggest that there may be structural homology among the toxin-binding sites on various types of K channels.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain / drug effects*
  • Calcium / pharmacology*
  • Charybdotoxin
  • Potassium Channels / drug effects*
  • Rats
  • Scorpion Venoms / toxicity*
  • Synaptosomes / drug effects*

Substances

  • Potassium Channels
  • Scorpion Venoms
  • Charybdotoxin
  • Calcium