Different binding properties of two general-odorant binding proteins in Athetis lepigone with sex pheromones, host plant volatiles and insecticides.

Athetis lepigone (Alep) is a polyphagous pest native to Europe and Asia that has experienced major outbreaks in the summer maize area of China since 2011 and has shown evidence of resistance to some insecticides. Insect olfaction is crucial for recognition of sex pheromones, host plant volatiles and even insecticides, in which two general-odorant binding proteins (GOBPs) play important roles. To elucidate the functions of GOBPs in A. lepigone, we first expressed the two AlepGOBP proteins in the E. coli expression system. Then, the results of fluorescence competitive binding assays demonstrated that the high binding affinity of AlepGOBP2 with sex pheromones [(Z)-7-dodecenyl acetate (Z7-12:Ac), Ki = 0.65 µM; (Z)-9-tetradecenyl acetate (Z9-14:Ac), Ki = 0.83 µM], two maize plant volatiles [Ocimene, Ki = 9.63 µM; (E)-ß-Farnesene, Ki = 4.76 µM] and two insecticides (Chlorpyrifos Ki =5.61 µM; Phoxim, Ki = 4.38 µM). However, AlepGOBP1 could only bind Ocimene (Ki = 13.0 µM) and two insecticides (Chlorpyrifos Ki =4.46 µM; Phoxim, Ki = 3.27 µM). These results clearly suggest that AlepGOBP1 and AlepGOBP2 differentiate among odorants and other ligands. The molecular docking results further revealed different key residues involved in the ligand binding of AlepGOBPs. In summary, this study provides a foundation for exploring the olfactory mechanism of A. lepigone and identified two potential target genes for the development of highly effective insecticides in the future.

Self-Assembly of Integrin Ligands on the Apical Membrane Inhibits the Migration of Glioma Cells.

Malignant brain cancer remains challenging in treatment due to the highly invasive quality of gliomas. Inspired by the upregulated expression of integrin ß1 subunits in tumors, we designed and synthesized an integrin-targeting self-assembling ligand based on a laminin-derived peptide that selectively forms nanofibrous microdomains on the apical membrane of glioma cells, inhibiting their migration and invasion.