Molecular Recognition of Odorant‐Binding Proteins WmagOBP39280 and WmagOBP42531 to Wohlfahrtia magnifica Pheromones and Bactrian Camel Volatiles

ABSTRACT

Wohlfahrtia magnifica , a worldwide pest, causes myiasis in many domestic animals. Its pheromones and volatiles from Bactrian camels were reported to attract or repel W. magnifica , but the molecular mechanisms are still unclear. A small protein in the insect olfactory system, called odorant binding protein (OBP), plays a crucial role in odor reception. In this study, two W. magnifica odorant‐binding proteins (WmagOBPs) genes, WmagOBP42531 and WmagOBP39280, were cloned from the antennae of W. magnifica , and then expressed and purified by prokaryotic expression. Fluorescence binding assays demonstrated that WmagOBP39280 exhibits high binding affinity to methylheptenone, butylbutyrate, p‐ ethylacetophenone, acetophenone ( K _i : 4.69, 4.15, 3.48, 4.06), while WmagOBP42531 exhibits high binding affinity to p‐ ethylacetophenone and dipentene ( K _i : 4.85, 4.98) and moderate binding to methylheptenone, 1‐octene‐3‐ol, acetophenone, ethylbenzene. o ‐xylene ( K _i : 7.00, 5.96, 5.72, 7.86, 6.15). Molecular docking and molecular dynamics simulation results suggest that a stable complex could be formed between WmagOBP42531 and 1‐octene‐3‐ol, acetophenone, p ‐ethylacetophenone, or o ‐xylene; between WmagOBP39280 and acetophenone, butylbutyrate, p ‐ethylacetophenone, or methylheptenone, with Gibbs free energy (ΔG) ranging from −26.84 to −14.7 kcal/mol. RMSD, RMSF, and radius of gyration suggested the spontaneous binding of WmagOBP42531 and WmagOBP39280 to odor ligands.