Characterization of three pheromone-binding proteins (PBPs) of Helicoverpa armigera (Hübner) and their binding properties

Three pheromone-binding proteins of Helicoverpa armigera were cloned and expressed in Escherichia coli. In order to characterize their physiological properties, ligand-binding experiments were performed using five biologically relevant substances including sex pheromones and interspecific signals. The results showed that one of the pheromone-binding proteins, HarmPBP1, binds strongly to each of the two principal pheromone components of H. armigera, (Z)-11-tetradecenal and (Z)-9-hexadecenal, but not to the interspecific signal (Z)-9-tetracecenal. The two remaining pheromone-binding proteins, HarmPBP2 and HarmPBP3, showed only weak affinities with the ligands tested. The 3-D structure of HarmPBP1 was predicted and the docking experiments indicate that the key binding site of (Z)-9-hexadecenal to HarmPBP1 includes Thr112, Lys111, and Phe119 whereas that of (Z)-11-tetradecenal includes Ser9, Trp37, Phe36, and Phe119.

Graphical abstractPheromone binding proteins of Helicoverpa armigera were binding with two sex pheromone components (Z) 11-tetradecenal and (Z) 9-hexadecenal, and some interspecific signals.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We get three PBPs from the cDNA library of the antennae of Helicoverpa armigera. ► Analyzed the three PBP genes with other Lepidoptera. ► Expressed the three PBPs in E. coli and purified them. ► Tested five sex pheromones with each PBP by binding experiment.