Virtual Evaluation of Insecticidal Potential of Fused Vip3Aa and Garlic Lectin against Fall Armyworm (Spodoptera frugiperda)

Abstract

The use of transgenic crops to combat insect infestation has been proven to be an effective and environment-friendly approach. However, insecticidal proteins with a single mode of action are prone to the development of insect resistance. Researchers are now interested in combining insecticidal proteins to acquire multiple modes of action to address that problem. Here, we have performed a virtual evaluation of a fusion protein that was in silico constructed by combining the vegetative insecticidal protein (Vip3Aa) of Bacillus thurengensis and the garlic leaf lectin of Allium sativum (ASAL) with a flexible peptide linker (GGGGS)3. Two fusion modes were conducted, one with ASAL as the N-terminus (AV) and the other where Vip3Aa is the N-terminus (VA) of the fusion construct. Molecular dynamics simulation of the fusion constructs (AV and VA) revealed their differences in conformational changes and compactness, with VA being more stable and favorable. Protein-protein docking studies against the fall armyworm aminopeptidase-N of S. frugiperda resulted in the identification of interacting residues at the interface. A novel fusion protein proposed in this study would be valuable for rational design of potent insecticidal proteins with multiple modes of action.