Scorpion insect neurotoxin LqhIT2 is a promising oral biopesticide: high-level preparation in Pichia pastoris and bioactivity assays.

Background: Discovering insecticidal proteins with high activity and strict insect specificity and applying them to the biological control of insect pests is of great significance. Oral LqhIT2 has insecticidal activity, which most other insecticidal neurotoxin proteins do not have, but the large-scale preparation of the toxin is difficult and one of the obstacles to determining its anti-insect potential for biological control.

Results: In this study, the expression level of recombinant LqhIT2 (rLqhIT2) in Pichia pastoris was as high as 1.

The fusion protein of scorpion neurotoxin BjαIT and Galanthus nivalis agglutinin (GNA) enhanced the injection insecticidal activity against silkworms, but only has lethal activity against newly hatched larva when administered orally.

Fusing insect derived neurotoxic peptides with Galanthus nivalis agglutinin (GNA) has been shown to enhance the insecticidal activity of the neuropeptides, especially when administered orally. This study produced a recombinant scorpion insect specific neurotoxin BjαIT, GNA, and a fusion protein BjαIT/GNA using Pichia pastoris as an expression host. Recombinant rBjαIT/GNA was found to be easily degraded during expression in yeast which and produced a main protein product with a molecular weight of approximately 14 kDa.