Iberiotoxin

Iberiotoxin is a toxin isolated from Buthus tamulus scorpion venom. Iberiotoxin is a selective high conductance high conductance Ca2+-activated K+ channel inhibitor with a Kd of ~1 nM. Iberiotoxin does not block other types of voltage-dependent ion channels[1][2][3].

O=C([C@@H](NC([C@@H](N1)CCC1=O)=O)CC2=CC=CC=C2)N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(NCC(N[C@H](C(N[C@H](C(N[C@H](C(NCC(N[C@H]3CCCCN)=O)=O)CCCNC(N)=N)=O)CC(O)=O)=O)C(C)C)=O)=O)CC4=CC=CC=C4)=O)CC(C)C)=O)CC(O)=O)=O)CCCCN)=O)CSSC[C@@H](C(N[C@H](C(N[C@H](C(O)=O)CCC(N)=O)=O)CC5=CC=C(O)C=C5)=O)NC6=O)=O)C(C)C)=O)CO)=O)CC7=CNC8=CC=CC=C78)=O)CSSC[C@@H](C(N[C@H]6CCCNC(N)=N)=O)NC9=O)=O)CCC(O)=O)=O)CCCCN)=O)CO)=O)C(C)C)=O)CO)=O)CSSC[C@@H](C(N[C@H](C(NCC(N[C@H](C(N[C@H]9CCCCN)=O)CCCCN)=O)=O)CCSC)=O)NC3=O)=O)CC(O)=O)=O)C(C)C)=O)CC(O)=O)=O)[C@@H](C)O

[1] A Galvez, et al. Purification and Characterization of a Unique, Potent, Peptidyl Probe for the High Conductance Calcium-Activated Potassium Channel From Venom of the Scorpion Buthus Tamulus. J Biol Chem. 1990 Jul 5;265(19):11083-90.|[2]Santiago Echeverry, et al. Activation of BK Channel Contributes to PL-Induced Mesenchymal Stem Cell Migration. Front Physiol. 2020 Mar 24;11:210.|[3]S Candia, et al. Mode of Action of Iberiotoxin, a Potent Blocker of the Large Conductance Ca(2+)-activated K+ Channel. Biophys J. 1992 Aug;63(2):583-90.|[4]R J Wang, et al. Downregulation of Large Conductance Calcium-Activated Potassium Channels in Paraventricular Nucleus Contributes to Sympathoexcitation in Rats With Chronic Heart Failure. Zhonghua Xin Xue Guan Bing Za Zhi. 2018 Mar 24;46(3):178-186.