Functional expression of olfactory receptor and its application for biomimetic sensors

Abstract

ODR-10, an olfactory receptor protein of C. elegans, was used as a model of olfactory receptors expressed in human embryonic kidney (HEK)-293 cells as a fusing protein with 6×his-tag and rho-tag. The expression of the target protein was analyzed by RT-PCR (reverse transcription-polymerase chain reaction), Western blot and immunocytochemistry methods. The specific binding to odorant molecules of the olfactory receptor was measured using intracellular Ca 2+ assays. Then the olfactory receptor ODR-10 was immobilized onto the surface of quartz crystal microbalance (QCM) sensor to fabricate the olfactory receptor-based gas biosensor. The results demonstrated that this biosensor can detect the natural ligand of ODR-10 (diacetyl) with high sensitivity and specificity. All these results indicated that the olfactory receptor ODR-10 has been expressed successfully in the heterologous cell system and it can be used as the sensitive material in the development of biomimetic olfactory receptor-based biosensors.