Novel paradigms on scorpion toxins that affects the activating mechanism of sodium channels.
Scorpion toxins classified as beta-class are reviewed using a new paradigm. Four distinct sub types are recognized: "classical", "Tsgamma-like", "excitatory" and "depressant"beta-scorpion toxins. Recent experimental data have made possible to identify the interacting interfaces of the Na(+) channel-receptor site 4 with some of these toxins. The voltage-sensor trapping mechanism proposed for the action of these toxic peptides is analyzed in the context of what causes a modification of the activating mechanism of Na(+) channels. A cartoon model is presented with the purpose of summarizing the most current knowledge on the field. Finally, the recent advances on the knowledge of the specific interactions of beta-toxins and different sub types of Na(+) channels are also reviewed.
de la Vega
Ricardo C Rodríguez
RC
Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Av. Universidad 2001, Cuernavaca Morelos 62210, México. delavega@ibt.unam.mx
Possani
Lourival D
LD
D000818:Animals; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D012604:Scorpion Venoms / Q000494:pharmacology*; D026941:Sodium Channel Blockers / Q000494:pharmacology*; D015222:Sodium Channels / Q000187:drug effects*; D062585:Voltage-Gated Sodium Channel beta-4 Subunit
C477263:SCN4B protein, human; D012604:Scorpion Venoms; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D062585:Voltage-Gated Sodium Channel beta-4 Subunit