Polypeptide neurotoxins alter ion channel gating by binding to extracellular receptor sites, even though the voltage sensors are in their S4 transmembrane segments. By analysis of sodium channel chimeras, a beta-scorpion toxin is shown here to negatively shift voltage dependence of activation and enhance closed state inactivation by binding to a receptor site that requires glycine 845 (Gly-845)...

BACKGROUND Symptomatic acute epileptic seizures may occur in up to 5% of individuals, especially children, with scorpion stings. The occurrence of a long-lasting brain lesion or the development of epilepsy after a scorpion sting has never been observed. OBJECTIVE To describe the development of epilepsy secondary to an extensive hemispheric destructive brain lesion after a scorpion sting. PA...

The unique fold of scorpion toxins is a natural scaffold for protein engineering, in which multiple disulfide bonds are crucial structural elements. To understand the respective roles of these disulfide bridges, a mutagenesis analysis for the four disulfide bonds, 12-63, 16-36, 22-46 and 26-48, of a representative toxin BmK M1 from the scorpion Buthus martensii Karsch was carried out. All cyste...

Proteomic analysis of the scorpion venom Scorpio maurus palmatus was performed using reverse-phase HPLC separation followed by mass spectrometry determination. Sixty five components were identified with molecular masses varying from 413 to 14,009 Da. The high percentage of peptides (41.5%) was from 3 to 5 KDa which may represent linear antimicrobial peptides and KScTxs. Also, 155 expressed sequ...

Potassium channels are involved in the maintenance of resting membrane potential, control of cardiac and neuronal excitability, neurotransmitters release, muscle contractility and hormone secretion. The Tityus stigmurus scorpion is widely distributed in Northeastern Brazil and known to cause severe human envenomations, inducing pain, hypoesthesia, edema, erythema, paresthesia, headaches and vom...