In-silico and in-vitro expression of Vigna aconitifolia lectin for insecticidal activity

Abstract

Lectin proteins are ubiquitously present in all life forms with various biological functions. Current study covers in silico analysis of Vigna aconitifolia lectin (Valectin) protein sequences, aiming identification of functional conserved domains and to predict its tertiary structures with different ligands. This study was carried out at ICAR-NIPB and division of entomology at ICAR-IARI, Pusa,New Delhi during 2015-18. Molecular Docking study of Valectin against alanylaminopeptidase N (APN) receptor of Acyrthosiphon pisum (pea aphid) revealed that ASP159, SER161, GLU164, SER181, ASN178, VAL177, SER35, VAL94, ASN92, LYS 141, ARG85, GLU138 and TYR139 residues of Valectin are critical for the interaction with insect receptor. The efficacy of Valectin protein was confirmed using wet lab experiments including molecular cloning, in-vitro expression and aphid bioassay. Western blot analysis using Anti-His antibody conjugate confirmed the presence of recombinant Valectin protein and characterized as ~30 kDa in size. The insecticidal potential of this protein was explored and bioassay results showed mortality of 59.25%, 66.66%, and 70.36% at concentration of 1, 10 and 20 μg/ml upon 96 h incubation against Lipaphis erysimi. Present studies by using various bio-computational tools will augment our understanding about the Valectin structure and could be used as a potential candidate gene for generating transgenic of crop plants for increased aphid resistance.