Title
The Drosophila odorant-binding protein 28a is involved in the detection of the floral odour ß-ionone
Author
Daniel Gonzalez, Karen Rihani, Fabrice Neiers, Nicolas Poirier, Stéphane Fraichard, Guillaume Gotthard, Thomas Chertemps, Martine Maïbèche, Jean-François Ferveur, Loïc Briand
Year
2019
Journal
Cellular and Molecular Life Sciences
Abstract
Odorant-binding proteins (OBPs) are small soluble proteins that are thought to transport hydrophobic odorants across the aqueous sensillar lymph to olfactory receptors. A recent study revealed that OBP28a, one of the most abundant Drosophila OBPs, is not required for odorant transport, but acts in buffering rapid odour variation in the odorant environment. To further unravel and decipher its functional role, we expressed recombinant OBP28a and characterized its binding specificity. Using a fluorescent binding assay, we found that OBP28a binds a restricted number of floral-like chemicals, including ß-ionone, with an affinity in the micromolar range. We solved the X-ray crystal structure of OBP28a, which showed extensive conformation changes upon ligand binding. Mutant flies genetically deleted for the OBP28a gene showed altered responses to ß-ionone at a given concentration range, supporting its essential role in the detection of specific compounds present in the natural environment of the fly.
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Protein folding, Biochemistry