title: Scorpion beta-toxins and voltage-gated sodium channels: interactions and effects.
abstract: Scorpion beta-toxins (beta-ScTxs) modify the activity of voltage-gated sodium (Nav) channels, thereby producing neurotoxic effects in diverse organisms. For this reason, beta-ScTxs are essential tools not only for discriminating among different channel sub-types but also for studying the mechanisms of channel gating and the structure-function relationship involved in this process. This review considers both the structural and the functional implications of the beta-ScTxs after they bind to their receptor sites, in accord with their classification into a) anti-mammalian beta-ScTxs, b) anti-insect selective excitatory beta-ScTxs, c) anti-insect selective depressant beta-ScTxs and d) beta-ScTxs active on both insect and mammals Nav channels. Additionally, the molecular mechanism of toxin action by the "voltage sensor trapping" model is discussed, and the systemic effects produced by these toxins are reviewed.
authors.affiliation: Instituto de Biotecnologia, UNAM, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico. mapedmx@ibt.unam.mx
authors.forename: Martha
authors.initials: M
authors.lastname: Pedraza Escalona
authors.forename: Lourival D
authors.initials: LD
authors.lastname: Possani
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018698:Glutamic Acid / Q000502:physiology; D006801:Humans; D007313:Insecta / Q000187:drug effects; D008322:Mammals; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000494:pharmacology; D012604:Scorpion Venoms / Q000737:chemistry / Q000494:pharmacology*; D012605:Scorpions / Q000378:metabolism; D016415:Sequence Alignment; D061566:Voltage-Gated Sodium Channels / Q000187:drug effects* / Q000502:physiology*
chemical_list: D009498:Neurotoxins; D012604:Scorpion Venoms; D061566:Voltage-Gated Sodium Channels; D018698:Glutamic Acid