Scorpion toxins as tools for studying potassium channels.

The search for peptidyl inhibitors of K+ channels is a very active area of investigation. In addition to scorpion venoms, other venom sources have been investigated; all of these sources have yielded novel peptides with interesting properties. For instance, spider venoms have provided peptides that block other families of K+ channels (e.g., Kv2 and Kv4) that act via mechanisms which modify the gating properties of these channels. Such inhibitors bind to a receptor on the channel that is different from the pore region in which the peptides discussed in this chapter bind. In fact, it is possible to have a channel occupied simultaneously by both inhibitor types. It is expected that many of the methodologies concerning peptidyl inhibitors from scorpion venom, which have been developed in the past and outlined above, will be extended to the new families of K+ channel blockers currently under development.