Virtual screening, molecular dynamics and binding energy-MM-PBSA studies of natural compounds to identify potential EcR inhibitors against Bemisia tabaci Gennadius

Abstract

Whitefly (Bemisia tabaci Gennadius) is a hmpteran phyto polyphagous sucking insect pest which is an important pest of cotton that causes economic losses to the crop by reducing its yield and quality. Ecdysteroids like 20-hydroxy ecdysone (20-E), have significant role in larval moulting, development, and reproduction in pterygota insects. Intending to obstruct these fundamental, developmental physiological processes, the receptor of 20-E, the Ecdysone Receptor (BtEcR) of Bemisia tabaci has been targeted. To identify potent inhibitors of BtEcr, 98,072 natural compounds were retrieved from ZINC database. A structure-based virtual screening of these compounds was conducted for their binding to BtEcR and the top two compounds (ZINC08952607 and ZINC04264850) were selected based on minimum binding energy. 50 ns molecular dynamics simulation (MDS) study was then performed for the prediction of dynamics and stability of BtEcR and top-scoring ligand-BtEcR complexes. Besides, g_mmpbsa tool was used to calculate and analyse binding free energy of BtEcR-ligand complexes. The results revealed that ZINC08952607 and ZINC04264850 had binding free energy of −170.156 kJ/mol and −200.349 kJ/mol, respectively. Thus, these ligands can be utilized as lead compounds for the development of environmentally safe insecticides against the whitefly.