title: Insights into structural features determining odorant affinities to honey bee odorant binding protein 14.
abstract: Molecular interactions between odorants and odorant binding proteins (OBPs) are of major importance for understanding the principles of selectivity of OBPs towards the wide range of semiochemicals. It is largely unknown on a structural basis, how an OBP binds and discriminates between odorant molecules. Here we examine this aspect in greater detail by comparing the C-minus OBP14 of the honey bee (Apis mellifera L.) to a mutant form of the protein that comprises the third disulfide bond lacking in C-minus OBPs. Affinities of structurally analogous odorants featuring an aromatic phenol group with different side chains were assessed based on changes of the thermal stability of the protein upon odorant binding monitored by circular dichroism spectroscopy. Our results indicate a tendency that odorants show higher affinity to the wild-type OBP suggesting that the introduced rigidity in the mutant protein has a negative effect on odorant binding. Furthermore, we show that OBP14 stability is very sensitive to the position and type of functional groups in the odorant.
authors.affiliation: Austrian Institute of Technology GmbH, AIT, Donau-City Str. 1, 1220 Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schwaighofer
authors.affiliation: Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria.
authors.forename: Maria
authors.initials: M
authors.lastname: Pechlaner
authors.affiliation: Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria.
authors.forename: Chris
authors.initials: C
authors.lastname: Oostenbrink
authors.affiliation: Center of Electrochemical Surface Technology, CEST, Viktor-Kaplan-Straße 2, 2700 Wiener Neustadt, Austria.
authors.forename: Caroline
authors.initials: C
authors.lastname: Kotlowski
authors.affiliation: Institut für Biologische Chemie, Universität Wien, Währinger Straße 38, 1090 Wien, Austria.
authors.forename: Can
authors.initials: C
authors.lastname: Araman
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Mastrogiacomo
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.affiliation: Austrian Institute of Technology GmbH, AIT, Donau-City Str. 1, 1220 Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Knoll
authors.affiliation: Austrian Institute of Technology GmbH, AIT, Donau-City Str. 1, 1220 Vienna, Austria; Center of Electrochemical Surface Technology, CEST, Viktor-Kaplan-Straße 2, 2700 Wiener Neustadt, Austria. Electronic address: c.nowak@ait.ac.at.
authors.forename: Christoph
authors.initials: C
authors.lastname: Nowak
authors.affiliation: Austrian Institute of Technology GmbH, AIT, Donau-City Str. 1, 1220 Vienna, Austria. Electronic address: Melanie.Larisika@ait.ac.at.
authors.forename: Melanie
authors.initials: M
authors.lastname: Larisika
mesh_terms: D000818:Animals; D001516:Bees / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D009154:Mutation; D009812:Odorants / Q000032:analysis; D055550:Protein Stability; D018035:Receptors, Odorant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D019476:Insect Proteins; D018035:Receptors, Odorant; C045648:odorant-binding protein
keywords: Circular dichroism; Ligand binding; Molecular dynamics; Odorant binding protein; Thermal stability