Fine discrimination of volatile compounds by graphene-immobilized odorant-binding proteins

SENSORS AND ACTUATORS B-CHEMICAL

卷:256

Article

Kotlowski, Caroline^1,2  Larisika, Melanie^1,2  Guerin, Patrick M.³  Kleber, Christoph¹  Krober, Thomas³  Mastrogiacomo, Rosa⁴  Nowak, Christoph^1,2  Pelosi, Paolo⁴  Schutz, Stefan⁵  Schwaighofer, Andreas⁶  Knoll, Wolfgang^1,2 

[1] Ctr Elect Surface Technol, A-2700 Wiener Neustadt, Austria

[2] Austrian Inst Technol, A-1190 Vienna, Austria

[3] Univ Neuchatel, Inst Biol, CH-2000 Neuchatel, Switzerland

[4] Univ Pisa, Dept Agr Food & Environm, I-56124 Pisa, Italy

[5] Univ Gottingen, Dept Forest Zool & Forest Conservat, Buesgen Inst, D-37077 Gottingen, Germany

[6] Vienna Univ Technol, Inst Chem Technol & Analyt, Getreidemarkt 9-164 UPA, A-1060 Vienna, Austria

关键词: Honeybee (Apis mellifera);    Odorant detection;    Odorant-binding protein;    Reduced graphene oxide;    Olfactory electronic biosensor;    Field-effect transistor;   

DOI  :  10.1016/j.snb.2017.10.093

来源: Elsevier

【 摘 要 】

We describe the fabrication and performance of a biosensor for odorants, using wildtype and engineered mutants of the Italian honeybee (Ap is mellifera ligustica) odorant binding protein 14 (OBP14), immobilized onto a reduced graphene oxide field-effect transistor (rGO-FET). The binding properties of the protein when immobilized on the biosensor are similar to those measured in solution, thus providing a method for measuring affinities to small molecules as an alternative to the current fluorescence assay. Out of the 14 chemicals tested, the best ligands for wildtype OBP14 were eugenol, homovanillic acid and related compounds sharing a phenol-methoxy backbone. Other chemicals, including methyl eugenol, showed affinities to OBP14 100-1000 times lower. We have also tested two mutants of OBP14. The first, bearing a HisTag at its N-terminus for better orientation on the sensor surface, showed only minor differences in its binding properties for chemicals when compared to the wildtype. The second contained an additional disulfide bond between helices alpha 3 and alpha 6, thus reducing the dynamics of OBP14 and leading to a higher affinity for eugenol. These data also demonstrate that it is feasible to produce biosensors with desired ligand specificities by introducing selected mutations into the structure of OBPs or other active proteins. (C) 2017 Published by Elsevier B.V.

【 授权许可】

Free