Expression And Functional Analysis Of A Recombinant Scorpion Neurototoxin AaIT

Based upon the amino acid sequences, insect-specific neurotoxin AaIT gene was designed and synthesized according to the bias in codon choice of E.coli. The AaIT gene was cloned into expression vector pET32a+ to construct the recombinant plasmid pET32a-AaIT, which was then transformed into E.coli Origami (DE3) strain. With IPTG induction, the fusion protein was expressed solubly, unfortunately, it had no biological activity. The AaIT gene was cloned into the yeast expression vector pPIC6αA resulting in the recombinant vector pPIC6αA-AaIT. The pPIC6αA-AaIT plasmid was linearized with Sal I and transformed to P. pastoris X-33 strain. Induced with methanol, the fusion protein AaIT was highly secreted expressed. The recombinant toxin was biologically active against Spodoptera exigua and Argyrogramma agnata by injection.