Pheromone discrimination by the pheromone-binding protein of Bombyx mori.
Pheromone-binding proteins are postulated to contribute to the exquisite specificity of the insect's olfactory system, acting as a filter by preferentially binding only one of the components of the natural pheromone. Here, we investigated the possible discrimination of the two very similar components of the natural pheromone gland from the silk moth, Bombyx mori, bombykol and bombykal, by the only pheromone-binding protein (BmorPBP) known to be expressed in the pheromone-detecting sensilla. Free-energy calculations and virtual docking indicate that both bombykol and bombykal bind to BmorPBP with similar affinity. In addition, in vitro competitive binding assays showed that both bombykol and bombykal were bound by BmorPBP with nearly the same high affinity. While BmorPBP might filter out other physiologically irrelevant compounds hitting the sensillar lymph, discrimination between the natural pheromone compounds must be achieved by molecular interactions with their cognate receptors.
Gräter
Frauke
F
Department of Theoretical and Computational Biophysics, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
Xu
Wei
W
Leal
Walter
W
Grubmüller
Helmut
H
D000466:Alkadienes / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D012831:Bombyx / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry*; D003198:Computer Simulation; D005233:Fatty Alcohols / Q000737:chemistry; D006860:Hydrogen Bonding; D019476:Insect Proteins / Q000737:chemistry*; D036341:Intercellular Signaling Peptides and Proteins; D008958:Models, Molecular; D010675:Pheromones / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D013816:Thermodynamics
D000466:Alkadienes; D000596:Amino Acids; D002352:Carrier Proteins; D005233:Fatty Alcohols; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010675:Pheromones; C403094:pheromone-binding protein, Bombyx; C066482:bombykal; C006787:bombykol