Mechanistic events underlying odorant binding protein chemoreception.
Odorant binding proteins (OBP's) are small hydrophilic proteins, belonging to the lipocalin family dedicated to bind and transport small hydrophobic ligands. Despite many works, the mechanism of ligand binding, together with the functional role of these proteins remains a topic of debate and little is known at the atomic level. The present work reports a computational study of odorants capture and release by an OBP, using both constrained and unconstrained simulations, giving a glimpse on the molecular mechanism of chemoreception. The residues at the origin of the regulation of the protein door opening are identified and a tyrosine amino-acid together with other nearby residues appear to play a crucial role in allowing this event to occur. The simulations reveal that this tyrosine and the protein's L5 loop are implicated in the ligand contact with the protein and act as an anchoring point for the ligand. The protein structural features required for the ligand entry are highly conserved among many transport proteins, suggesting that this mechanism could somewhat be extended to some members of the larger family of lipocalin.
Golebiowski
Jérôme
J
Laboratoire de Chimie des Molecules Bioactives et des Aromes, Faculté des sciences de Nice-Sophia Antipolis, Centre National de la Recherche Scientifique, UMR 6001, Université de Nice-Sophia-Antipolis, France. jerome.golebiowski@unice.fr
Antonczak
Serge
S
Fiorucci
Sébastien
S
Cabrol-Bass
Daniel
D
D000596:Amino Acids; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D019295:Computational Biology; D003198:Computer Simulation; D017124:Conserved Sequence; D008024:Ligands; D008958:Models, Molecular; D011485:Protein Binding; D018035:Receptors, Odorant / Q000737:chemistry* / Q000378:metabolism
D000596:Amino Acids; D002352:Carrier Proteins; D008024:Ligands; D018035:Receptors, Odorant; C045648:odorant-binding protein