Exploring the different inhibitors of Apis dorsata amylase inhibitors from different plant sources using docking approach

Abstract

The putative protein sequence of amylase from honey bee Apis dorsata was retrieved through NCBI database (GenBank ID XP_006614569.1) consisting of 493 amino acids. To identify the conserved residues, and domains in Apis α-amylase, the protein sequence was aligned with six other amylase sequences from Apis cerana (95%), Apis mellifera (94%), Drosophila ananassae (65%), Drosophila punjabiensis (61%), Drosophila melanogaster (59%) and Tenebrio molitor (59%). The presence of three active site residues (Asp²⁰⁷, Glu²⁴⁴ and Asp³⁰⁹) in catalytic domain along with domain B, and CBM-domain C showed that A. dorsata amylase is active and belong to family GH13. Plant inhibitors like luteolin, rosmarinic acid, saponin II and azadiriadone were docked on active site of amylase using Autodock Vina program with binding energy -9.2 to -6.3 Kcal/mol. Azadiradone, luteolin and rosmarinic acid interacted with catalytic residues as well as substrate binding site, thus blocking both sites. While saponin II showed little interactions with catalytic site residues but it was strongly associated with Lys³⁵² present in a loop right above the active site, which is conserved in all α-amylases of Apis species. Amylase of Apis dorsata is a calcium dependent enzyme like all Apis amylases due to the presence of four functional active residues (Asn¹¹⁸, Arg¹⁶⁸, Asp¹⁷⁷ and His²¹¹). This inhibitor’s effect shall be useful in developing potential insecticides and pesticides.