Synonyms: IbTX
Compound class:
Peptide
Comment: From the venom gland of Mesobuthus tamulus (Eastern Indian scorpion). Iberiotoxin is selective for KCa1.1 channels that associate with β1, β2 and β3 regulatory subunits [1-3]. In contrast the KCa1.1 channels containing the β4 subunit that are found predominantly in the central nervous system are resistant to iberiotoxin inhibition [6]
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Immunopharmacology Comments |
Iberiotoxin is somewhat selective for KCa1.1 channels that associate with β3b regulatory subunits that are expressed by invasive RA fibroblast-like synoviocytes [4], a cell-type involved in rheumatoid arthritis (RA) progression [5]. This selectivity should spare the CNS KCa1.1 β4 channels, and limit the CNS side-effects associated with non-selective inhibitors like paxilline. Efficacy of iberiotoxin-mediated KCa1.1 channel blockade on fibroblast-like synoviocytes in rodent models of RA suggests this molecular mechanism as a novel approach for the development of RA therapeutucs [5]. |