Iberiotoxin. A Potent and Specific Blocker of KCa1.1 (BK,�slo, Large Conductance Ca2+�Dependent K+) Channels.
Iberiotoxin�is a 37 amino acid peptidyl toxin isolated�from the scorpion�Mesobuthus tumulus�and was shown to�block large conductance Ca2+�activated K+�channels in smooth muscle cells.
Later it was shown to specifically block KCa1.1�(Slo) channels with Ki�of about 1 nM.
In addition, experiments with cloned KCa1.1 channels demonstrate the strong effect of the�slo(B) subunits on the potency of block by Iberiotoxin.