Recombinant expression and insecticidal properties of a Conus ventricosus conotoxin-GST fusion protein

► A system for heterologous expression of Conus ventricosus conotoxin Vn2 has been developed. ► Conotoxin Vn2 and its Asp2His mutant have been expressed fused to glutathione-S-transferase and purified to homogeneity. ► The toxicity of wild type and mutant conotoxins Vn2 has been assayed on the larvae of the moth Galleria mellonella. ► Conotoxin Vn2 has strong insecticidal properties at a dose of only 100 pmol/g of body weight. ► Mutation of Asp2 to His leads to enhanced toxicity in the larvae model system.