Iberiotoxin is a selective and reversible inhibitor of high-conductance calcium-activated potassium channel. A toxin purified from the Eastern Indian red scorpion Buthus tamulus.
Iberiotoxin, recombinant from Mesobuthus tamulus has been used as an inhibitor of large-conductance calcium-activated K+ channels to study its effect on the NLRP3 (nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3) inflammasome activation in bone marrow-derived macrophages (BMDMs). It has also been used to block Ca2+- activated K+ channels to determine interleukin(IL)-1β in BMDCs following inflammasome activation.
Selective probe for high-conductance calcium-activated potassium channels.
iberiotoxin is a 37 amino acid peptidyl toxin isolated from the scorpion mesobuthus tamulus and was shown to selectively block large conductance ca2+-activated k+ channels(bkca) in smooth muscle cells.in single channel recordings, iberiotoxin can reversibly block outward currents mediated by bkca in excised membrane patches from bovine aortic smooth muscle with an ic50 value of 250 pm. it is also a noncompetitive, partial inhibitor of charybdotoxin binding in bovine aortic sarcolemmal membrane vesicles (ki = 250 pm).[1]. galvez a, gimenez-gallego g, reuben j p, 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. the journal of biological chemisty, 1990, 265(19): 11083-11090.
The single chain peptide iberiotoxin (IbTX) is a selective and reversible inhibitor of high-conductance calcium-activated potassium channels (PK,Ca). It occurs naturally in the venom of the scorpion Buthus tamulus. IbTX also modulates the binding of charybdotoxin (CbTX) to smooth muscle sarcolemmal membranes in a non-competitive manner. IbTX is similar in size to CbTX and shares considerable sequence homology with CbTX. However, IbTX differs in its overall charge in having one fewer basic and four more acidic residues than CbTX.
