Slotoxin. A Novel, High Conductance Ca2+-Activated K+�(BK, KCa1.1) Channel Blocker
Native Slotoxin was originally isolated from Centruroides noxius scorpion venom. Native Slotoxin blocks the Maxi K (BKCa or slo, KCNMA1, KCa1.1) channels. Slotoxin blocks differentially channels formed by the alpha1 subunit alone and channels�formed by the alpha1 combined with auxiliary beta subunits. In Xenopus oocytes expressing hSlo (alpha1 alone), Kd was calculated to be 1.5 nM and the block is complete and reversible. With the additional co-expression of either the beta1 or beta4 subunits, the block becomes�irreversible or causes the channel to be almost insensitive to the toxin, respectively.
Ion Channel Modulators; K+�Channel Blockers.