LAUSR

Abstract Pulse beetle (Callosobruchus chinensis) is a cosmopolitan stored grain pest of legumes responsible for significant losses in them during storage. A proteinaceous α-amylase inhibitor, isolated and purified from Withania somnifera (WSAI), affected various growth and developmental parameters of Callosobruchus chinensis. Whereas female fecundity, adult emergence and % seed damaged were found to be reduced, mean development period and feeding deterrence index increased as a function of WSAI treatment. Almost 59% relative amylase activity was observed at 50 µg/mL of WSAI and confirmed by starch activity gel assay. Longevity of survived insects of treated sets was reduced by 2 days compared to control sets. Possible homology modelled structures for WSAI and C. chinensis proteins were proposed. The In-silico protein-protein docking studies revealed the hydrogen bonding network, binding energy (−16.5 Kcal) and amino acids involved in forming interactions which will be helpful in understanding the mechanism of inhibition in future. Graphical Abstract