Peptide toxins that selectively target insect Na(V) and Ca(V) channels.
Numerous metazoans express venoms for the purpose of defense, competitor deterrence or prey capture. Peptide neurotoxins are particularly well represented in the venoms of arachnids, cnidarians and mollusks and these toxins often possess high affinity and specificity for particular classes of ion channels. Some of these toxins have become the defining pharmacology for certain vertebrate ion channel subtypes. Unfortunately, due to differences in the structure, pharmacology and ion selectivity of insect voltage-gated sodium (Na(V)) and calcium (Ca(V)) channels compared with their vertebrate counterparts, these peptide toxins have proven less useful for the characterization of insect ion channels. Despite these disparities in channel structure and function, the armament of peptide toxins that specifically modulate the activity of insect ion channels is slowly expanding. This review focuses on insect-selective peptide toxins and their utility for the study of insect Na(V) and Ca(V) channels. The high affinity and selectivity of some of these neurotoxins means that they have the potential to become the defining pharmacology for specific subtypes of insect ion channels. In addition, it might be possible to exploit the phyletic specificity of these toxins as the basis for rational development of novel classes of ion channel insecticides.
Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia. glenn.king@imb.uq.edu.au
Glenn F
GF
King
Pierre
P
Escoubas
Graham M
GM
Nicholson
D000818:Animals; D015220:Calcium Channels / Q000187:drug effects*; D016503:Drug Delivery Systems; D007313:Insecta; D007306:Insecticides / Q000737:chemistry* / Q000494:pharmacology; D015640:Ion Channel Gating; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D015222:Sodium Channels / Q000187:drug effects*; D013111:Spider Venoms
D015220:Calcium Channels; D007306:Insecticides; D010455:Peptides; D015222:Sodium Channels; D013111:Spider Venoms