Fluorescent Ligands of Kv1 Channels on the Basis of Hongotoxin: Atto488-Hongotoxin

Development of fluorescently labeled peptide toxins, highly efficient and selective ligands of potassium (K+) channels, is an actual demand for different applications ranging from drug-screening techniques to in vitro and in vivo fluorescent imaging of K+ channels. Hongotoxin 1 (HgTx1), the 39-aa peptide toxin from the venom of scorpion Centruroides limbatus, is a potent blocker of potassium voltage-gated Kv1 -Kv3 channels. Its mutant forms, either radiolabeled ( 125 I-HgTX1-A19Y/Y37F) or fluorescently labeled (HgTX1-A19C) were used to probe localization in tissues [1], pharmacology [2] and subunit organization of .