Charybdotoxin
Charybdotoxin is a 37 amino acid peptide isolated from the venom of the scorpion Leiurus quinquestriatus hebraeus that blocks voltage gated and Ca2+ activated K+ channels. This blockade causes hyperexcitability of the nervous system. The toxin reversibly blocks channel activity by interacting at the external pore of the channel protein with an apparent Kd of 2.1 nM. ChTX also blocks Kv1.2 (Kd 14 nM) and Kv1.3 (Kd 2.6nM) channels.
Peptides & proteins
95751-30-7
Gimenez-Gallego G., et al. (1988) Purification, sequence, and model structure of charybdotoxin, a potent selective inhibitor of calcium-activated potassium channels. Proc. Natl. Acad. Sci. U.S.A.; Sugg E.E., et al. (1990) Synthesis and structural characterization of charybdotoxin, a potent peptidyl inhibitor of the high conductance Ca2(+)-activated K+ channel. J. Biol. Chem.; Goldstein SA, Miller C. (1993) Mechanism of charybdotoxin block of a voltage-gated K+ channel. Biophys J.; Goldstein SA, Pheasant DJ, Miller C. (1994) The charybdotoxin receptor of a Shaker K+ channel: peptide and channel residues mediating molecular recognition. Neuron.
RT