Structure and Function Studies of Asian Corn Borer Ostrinia furnacalis Pheromone Binding Protein2

Abstract

Lepidopteran male moths have an extraordinarily sensitive olfactory system that is capable of detecting and responding to minute amounts of female-secreted pheromones over great distances. Pheromone-binding proteins (PBPs) in male antennae ferry the hydrophobic ligand across the aqueous lymph to the olfactory receptor neuron triggering the response. PBPs bind ligands at physiological pH of the lymph and release them at acidic pH near the receptor while undergoing a conformational change. In Anthereae polyphemus PBP1, ligand binding to the hydrophobic pocket and its release is regulated by two biological gates: His70 and His95 at one end of the pocket and C-terminus tail at the other end. Interestingly, in Asian corn borer Ostrinia furnacalis PBP2 (OfurPBP2), critical residues for ligand binding and release are substituted in both biological gates. The impact of these substitutions on the ligand binding and release mechanism in OfurPBP2 is not known. We report here overexpression of soluble OfurPBP2 and structural characterization at high and low pH by circular dichroism (CD) and NMR. Ligand binding and ab initio model development were carried out with fluorescence and small-angle X-ray scattering (SAXS) respectively. OfurPBP2 in solution at pH 6.5 is homogeneous, well-folded and has a compact globular shape.

Ligand- and pH-Induced Structural Transition of Gypsy Moth Lymantria dispar Pheromone-Binding Protein 1 (LdisPBP1)

“…However, in studies that used delipidated samples, the A-form was not completely transformed into the B-form (at most ∼50%) at neutral pH. , This is the case observed in our pH titration of delipidated LdisPBP1. In contrast with BmorPBP, ApolPBP1, AtraPBP1, and OfurPBP2, the LdisPBP1 conformation at high pH showed extensive 1 H N – 15 N peak broadening and weak peak intensities in the 15 N HSQC spectra, which prevented elucidation of the second form by NMR.…”

AlepPBP2, but not AlepPBP3, may involve in the recognition of sex pheromones and maize volatiles inAthetis lepigone

“…In addition, all residues predicted were found to be consistent in the binding to both sex pheromones, indicating that these residues may be involved in the specific recognition of sex pheromones. It has been found that some residues may affect the structure of proteins (Dong et al ., 2017 b ; Mazumder et al ., 2018). Therefore, X-ray diffraction of protein–ligand complexes (Mazumder et al ., 2018) and the mutant binding assay (Laughlin et al ., 2008; Zhang et al ., 2020 b ) could be used to further analyze the molecular mechanisms of the interaction between insect PBPs and ligands.…”

“…It has been found that some residues may affect the structure of proteins (Dong et al ., 2017 b ; Mazumder et al ., 2018). Therefore, X-ray diffraction of protein–ligand complexes (Mazumder et al ., 2018) and the mutant binding assay (Laughlin et al ., 2008; Zhang et al ., 2020 b ) could be used to further analyze the molecular mechanisms of the interaction between insect PBPs and ligands.…”

Molecular Docking and Dynamics Simulation of Several Flavonoids Predict Cyanidin as an Effective Drug Candidate Against SARS-CoV-2 Spike protein

“…Periodic boundary conditions (PBC) were used with a constant number of particles in the system, constant pressure, and constant temperature (NPT) simulation criteria. Equilibration of the system at 1 bar pressure for 1 ns was connected using a Parrinello-Rahman Barostat in this simulation [39]. Using trajectories obtained from MD simulations Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), and the radius of gyration (Rg), were analyzed.…”