A recombinant fusion protein containing a spider toxin specific for the insect voltage-gated sodium ion channel shows oral toxicity towards insects of different orders

Yang, S.; Pyati, P.; Fitches, E.; Gatehouse, J.A.

Abstract

Recombinant fusion protein technology allows specific insecticidal protein and peptide toxins to display activity in orally-delivered biopesticides. The spider venom peptide δ-amaurobitoxin-PI1a, which targets insect voltage-gated sodium channels, was fused to the “carrier” snowdrop lectin (GNA) to confer oral toxicity. The toxin itself (PI1a) and an amaurobitoxin/GNA fusion protein (PI1a/GNA) were produced using the yeast Pichia pastoris as expression host. Although both proteins caused mortality when injected into cabbage moth (Mamestra brassicae) larvae, the PI1a/GNA fusion was approximately 6 times as effective as recombinant PI1a on a molar basis. PI1a alone was not orally active against cabbage moth larvae, but a single 30 μg dose of the PI1a/GNA fusion protein caused 100% larval mortality within 6 days when fed to 3rd instar larvae, and caused significant reductions in survival, growth and feeding in 4th – 6th instar larvae. Transport of fusion protein from gut contents to the haemolymph of cabbage moth larvae, and binding to the nerve chord, was shown by Western blotting. The PI1a/GNA fusion protein also caused mortality when delivered orally to dipteran (Musca domestica; housefly) and hemipteran (Acyrthosiphon pisum; pea aphid) insects, making it a promising candidate for development as a biopesticide.

Citation

Yang, S., Pyati, P., Fitches, E., & Gatehouse, J. (2014). A recombinant fusion protein containing a spider toxin specific for the insect voltage-gated sodium ion channel shows oral toxicity towards insects of different orders. Insect Biochemistry and Molecular Biology, 47, 1-11. https://doi.org/10.1016/j.ibmb.2014.01.007

• Journal Article Type: Article
• Acceptance Date: Jan 21, 2014
• Publication Date: Apr 1, 2014
• Deposit Date: Mar 2, 2015
• Publicly Available Date: May 8, 2015
• Journal: Insect Biochemistry and Molecular Biology
• Print ISSN: 0965-1748
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 47
• Pages: 1-11
• DOI: https://doi.org/10.1016/j.ibmb.2014.01.007
• Keywords: Neurotoxin, Insecticide, Recombinant protein expression system, Protein transport, Crop protection, Biotechnology.