The differential preference of scorpion alpha-toxins for insect or mammalian sodium channels: implications for improved insect control.

Journal Article (Review;Journal Article)

Receptor site-3 on voltage-gated sodium channels is targeted by a variety of structurally distinct toxins from scorpions, sea anemones, and spiders whose typical action is the inhibition of sodium current inactivation. This site interacts allosterically with other topologically distinct receptors that bind alkaloids, lipophilic polyether toxins, pyrethroids, and site-4 scorpion toxins. These features suggest that design of insecticides with specificity for site-3 might be rewarding due to the positive cooperativity with other toxins or insecticidal agents. Yet, despite the central role of scorpion alpha-toxins in envenomation and their vast use in the study of channel functions, molecular details on site-3 are scarce. Scorpion alpha-toxins vary greatly in preference for sodium channels of insects and mammals, and some of them are highly active on insects. This implies that despite its commonality, receptor site-3 varies on insect vs. mammalian channels, and that elucidation of these differences could potentially be exploited for manipulation of toxin preference. This review provides current perspectives on (i) the classification of scorpion alpha-toxins, (ii) their mode of interaction with sodium channels and pharmacological divergence, (iii) molecular details on their bioactive surfaces and differences associated with preference for channel subtypes, as well as (iv) a summary of the present knowledge about elements involved in constituting receptor site-3. These details, combined with the variations in allosteric interactions between site-3 and the other receptor sites on insect and mammalian sodium channels, may be useful in new strategies of insect control and future design of anti-insect selective ligands.

Full Text

Duke Authors

Cited Authors

  • Gordon, D; Karbat, I; Ilan, N; Cohen, L; Kahn, R; Gilles, N; Dong, K; Stühmer, W; Tytgat, J; Gurevitz, M

Published Date

  • March 2007

Published In

Volume / Issue

  • 49 / 4

Start / End Page

  • 452 - 472

PubMed ID

  • 17215013

Electronic International Standard Serial Number (EISSN)

  • 1879-3150

International Standard Serial Number (ISSN)

  • 0041-0101

Digital Object Identifier (DOI)

  • 10.1016/j.toxicon.2006.11.016

Language

  • eng