Can selective peptides be combined efficiently with agrochemicals? A new approach to insect control
✍ Scribed by Gordon, Dalia
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 125 KB
- Volume
- 55
- Category
- Article
- ISSN
- 1526-498X
No coin nor oath required. For personal study only.
✦ Synopsis
Sodium channels have been a major target for the development of insecticides such as synthetic pyrethroids. However, insecticides currently available induce resistance and present limited selectivity to insect pests. Molecular and biochemical studies, as well as binding experiments using radiolabelled neurotoxins, have shown that sodium channels expressed in various insect orders must be structurally and pharmacologically different. At least three groups of peptide neurotoxins derived from scorpion venom are highly active on insects and very weakly or practically inactive on mammals. It is proposed that various insecticides are examined for possible cooperative interactions with the peptide toxins highly active on insects, and pairs of ligands are identi®ed that will increase the selectivity not only between mammals and insects but also between different pest and non-pest insects. This is feasible on the basis of the differential allosteric modulations observed between LqhaIT, an a-toxin highly active on insects, and brevetoxin on locust versus cockroach and rat brain sodium channels. Moreover, combination of LqhaIT with the pyrethroid deltamethrin increased the binding of [ 125 I] LqhaIT by more than 1.8-fold, and the combined presence of brevetoxin further increased the binding. Such allosteric modulation may provide a new approach to increase the selective activity of pesticides on target organisms by simultaneous application of allosterically interacting drugs, designed on the basis of the selective peptide toxins.