In Silico Comparision of the Ligand Binding Domain of Ecdysone Receptor of Two Lepidopterous Insect Pests, Helicoverpa Armigera and Spodoptera Litura

The physiological process of molting in insects is governed by hormones. The ecdysteroid hormones coordinate the major stages of insect development by binding to the ecdysone receptor (EcR). Attempts to control insects through targeting the EcR are now gaining importance. In this study the protein sequence of ecdysone receptor of Helicoverpa armigera (Hub) and Spodoptera litura (Fab) were modeled specifically by extracting geometric restraints for corresponding atoms using the Homology modeling approach. The 3D structural comparison of the targets shows that the structures are closely related to each other with the low RMS value of 0.70Å. We analyzed the similarity in the ligand binding domain (LBD) of Ecdysone receptor of the lepidopteran pests by fixing the non-steroidal, synthetic agonist BYI06830 used in agrochemical pest control as the ligand. The comparison of EcR in complex with non-steroidal synthetic agonist results in partially overlapping residues in the LBD and the residue involved in the H-bond formation was found to be identical. We suggest that these findings of ligand-dependent binding pocket similarities have potential applications for developing a potent solution against the challenging pests.