A toxin to nervous, cardiac, and endocrine ERG K + channels isolated from Centruroides noxius scorpion venom

Toxins isolated from a variety of venoms are tools for probing the physiological function and structure of ion channels. The ether-a-go-go-related genes (erg) codify for the K+ channels (ERG), which are crucial in neurons and are impaired in human long-QT syndrome and Drosophila ‘seizure’ mutants. We have isolated a peptide from the scorpion Centruroides noxius Hoffmann that has no sequence homologies with other toxins, and demonstrate that it specifically inhibits (IC50=16±1 nM) only ERG channels of different species and distinct histogenesis. These results open up the possibility of investigating ERG channel structure–function relationships and novel pharmacological tools with potential therapeutic efficacy.—Gurrola, G. B., Rosati, B., Rocchetti, M., Pimienta, G., Zaza, A., Arcangeli, A., Olivotto, M., Possani, L. D., Wanke, E. A toxin to nervous, cardiac, and endocrine ERG K+ channels isolated from Centruroides noxius scorpion venom.