Charybdotoxin Refined model of Charybdotoxin Identifiers Symbol ? PDB 2crd Other data
Charybdotoxin (CTX) is a 37 amino acid neurotoxin from the venom of the scorpion Leiurus quinquestriatus hebraeus that blocks calcium-activated potassium channels. This blockade causes hyperexcitability of the nervous system.
Scorpions such as the deathstalker paralyze their prey by injecting a potent mix of peptide toxins. Charybdotoxin (CTX), a 37 amino acid neurotoxin, is one of the peptide toxins that can be extracted from the venom of the scorpion. Its structure is very similar to that of margatoxin. Charybdotoxin contains three disulfide bridges.
Mode of action
Charybdotoxin occludes the pore of calcium-activated voltage-gated K+ channels by binding to one of four independent, overlapping binding sites. It binds both to the open and the closed states. In addition, the block is enhanced as the ionic strength is lowered. The blockade of K+ channels by the charybdotoxin peptide causes neuronal hyperexcitability.
Anti-scorpion venom serum (AScVS) is an effective and safe method of therapy in severe scorpion envenoming syndrome. Compared with other therapies like alpha blockers it has a relatively short recovery period (10 vs 16–42 hours).
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- ^ Natu VS, Murthy RK, Deodhar KP (April 2006). "Efficacy of species specific anti-scorpion venom serum (AScVS) against severe, serious scorpion stings (Mesobuthus tamulus concanesis Pocock)—an experience from rural hospital in western Maharashtra". J Assoc Physicians India 54: 283–7. PMID 16944610.
Toxins (enterotoxin/neurotoxin/hemotoxin/cardiotoxin/phototoxin) Bacterial toxinsGram positiveCocciGram negative MycotoxinsAflatoxin · Amatoxin (alpha-amanitin, beta-amanitin, gamma-amanitin, epsilon-amanitin) · Citrinin · Cytochalasin · Ergotamine · Fumonisin (Fumonisin B1, Fumonisin B2) · Gliotoxin · Ibotenic acid · Muscimol · Ochratoxin · Patulin · Phalloidin · Sterigmatocystin · Trichothecene · Vomitoxin · Zeranol · Zearalenone Invertebrates Vertebratesreptile/snake venom: Bungarotoxin (Alpha-Bungarotoxin, Beta-Bungarotoxin) · Calciseptine · Taicatoxin · Calcicludine · Cardiotoxin IIInote: some toxins are produced by lower species and pass through intermediate species Channel blocker: potassium channel blockers Antiarrhythmic III/delayed rectifier Other/ungrouped/unknown
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