title: Isolation and characterization of two toxins from the Mexican scorpion Centruroides limpidus limpidus Karsch.
abstract: 1. Several toxic polypeptides were found in the venom of the scorpion Centruroides limpidus limpidus. Comparative studies of the potency of the venom in different strains of mice were conducted. 2. A new type of toxin (component II.9), specific for crustaceans (crayfish and isopods), was isolated from this scorpion and was shown to have the following N-terminal amino acid sequence: Lys-Lys-Asp-Gly-Tyr-Leu-Val-Asn-Lys-Tyr-Thr-Gly-Cys-Lys-Val-Asn-Cys- Tyr-Lys-Leu-Gly-Glu-Asn-Lys-Phe-Cys-Asn-Arg-Glu-. 3. A polypeptide toxic to mice (component II.6) from this venom was shown to have the following N-terminal sequence: Lys-Glu-Gly-Tyr-Leu-Val-Asn-His-Ser-Thr-Gly-Cys-Lys-Tyr- Glu-Cys-Tyr-Lys-Leu-Gly-Asp-Asn-Asp-Tyr-Cys-Leu-Arg-Glu-Cys-Lys-. 4. In cultured chick dorsal root ganglion cells, 1 microM of toxin II.6 was shown to reduce the size of sodium currents and to slow-down their activation-inactivation kinetics. The toxin had also a depressive action on the classical Ca2+ current activated at high membrane potentials (greater than 0 mV).
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004558:Electric Stimulation; D004594:Electrophysiology; D007473:Ion Channels / Q000187:drug effects; D007928:Lethal Dose 50; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D012604:Scorpion Venoms / Q000302:isolation & purification* / Q000633:toxicity; D012605:Scorpions; D012995:Solubility
chemical_list: D007473:Ion Channels; D012604:Scorpion Venoms