1. Isolation and characterization of a novel lepidopteran-selective toxin from the venom of South Indian red scorpion, Mesobuthus tamulus.
- Author
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Wudayagiri R, Inceoglu B, Herrmann R, Derbel M, Choudary PV, and Hammock BD
- Subjects
- Amino Acid Sequence, Animals, Biological Assay, Chromatography, High Pressure Liquid, Chromatography, Ion Exchange, Insecticides isolation & purification, Mice, Models, Molecular, Molecular Sequence Data, Scorpion Venoms isolation & purification, Sequence Alignment, Insecticides chemistry, Insecticides toxicity, Lepidoptera drug effects, Scorpion Venoms chemistry, Scorpion Venoms toxicity
- Abstract
Background: Scorpion venom contains insect and mammal selective toxins. We investigated the venom of the South Indian red scorpion, Mesobuthus tamulus for the purpose of identifying potent insecticidal peptide toxins., Results: A lepidopteran-selective toxin (Buthus tamulus insect toxin; ButaIT) has been isolated from this venom. The primary structure analysis reveals that it is a single polypeptide composed of 37 amino acids cross-linked by four disulfide bridges with high sequence homology to other short toxins such as Peptide I, neurotoxin P2, Lqh-8/6, chlorotoxin, insectotoxin I5A, insect toxin 15 and insectotoxin I1. Three dimensional modeling using Swiss automated protein modeling server reveals that this toxin contains a short alpha-helix and three antiparallel beta-strands, similar to other short scorpion toxins. This toxin is selectively active on Heliothis virescens causing flaccid paralysis but was non-toxic to blowfly larvae and mice., Conclusion: This is the first report of a Heliothine selective peptide toxin. Identification of diverse insect selective toxins offer advantages in employing these peptides selectively for pest control.
- Published
- 2001
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