Charybdotoxin blocks both Ca-activated K channels and Ca-independent voltage-gated K channels in rat brain synaptosomes.
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.
Schneider
M J
MJ
Department of Physiology, University of Maryland School of Medicine, Baltimore 21201.
Rogowski
R S
RS
Krueger
B K
BK
Blaustein
M P
MP
D000818:Animals; D001921:Brain / Q000187:drug effects*; D002118:Calcium / Q000494:pharmacology*; D018999:Charybdotoxin; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D012604:Scorpion Venoms / Q000633:toxicity*; D013574:Synaptosomes / Q000187:drug effects*
D015221:Potassium Channels; D012604:Scorpion Venoms; D018999:Charybdotoxin; D002118:Calcium