6533b829fe1ef96bd12899e7

RESEARCH PRODUCT

Electrochemical detection of the 2-isobutyl-3-methoxypyrazine model odorant based on odorant-binding proteins: The proof of concept

Maud SigoillotLoïc BriandEmilie BarouMarcel BouvetRita Meunier-prest

subject

Models MolecularIsothermal microcalorimetryOdorant bindingBiophysicsAnalytical chemistryCalorimetryReceptors OdorantElectrochemistryBinding CompetitiveCaffeic AcidsElectrochemistryPhysical and Theoretical ChemistryVoltammetryBinding SitesChemistryVitamin K 3Electrochemical TechniquesGeneral MedicineCombinatorial chemistryFluorescenceRecombinant ProteinsDissociation constantImmobilized ProteinsSpectrometry FluorescencePyrazinesCalibrationTitrationBiosensor

description

Abstract We developed an electrochemical assay for the detection of odorant molecules based on a rat odorant-binding protein (rOBP3). We demonstrated that rOBP3 cavity binds 2-methyl-1,4-naphtoquinone (MNQ), an electrochemical probe, as depicted from the decrease of its electrochemical signal, and deduced the dissociation constant, Kd MNQ  = 0.5(± 0.2) μM. The amount of MNQ displaced from rOBP3 by 2-isobutyl-3-methoxypyrazine (IBMP), a model odorant molecule, was measured using square-wave voltammetry. The release of MNQ by competition led to an increase of the electrochemical response. In addition, this method allowed determination of the dissociation constant of rOBP3 for IBMP, Kd IBMP  = 0.5(± 0.1) μM. A negative control was performed with a non-binding species, caffeic acid (CA). The determined binding affinity values were confirmed using a fluorescent competitive binding assay and isothermal titration microcalorimetry. This electrochemical assay opens the way for designing robust, reliable and inexpensive odorant biosensors.

yearjournalcountryeditionlanguage
2014-02-14Bioelectrochemistry
https://doi.org/10.1016/j.bioelechem.2014.06.006