A comparative study of the electrical properties of rat I7 and human17-40 olfactory receptors for the realization of a nanobiosensor

We present a procedure of investigation of the sensing protein behaviour when captures a molecule (ligand). In particular the procedure is applied to a couple of olfactory receptors (ORs), the human OR17-40 and the rat OR-I7. The interest in these proteins resides in the possible selection of olfactory receptors as sensing components of nanobiosensors. Accordingly, within a simple network model, we produce the impedance spectra of the ORs under consideration, in the native and activated state and analyze their differences. Furthermore, we get insights on the protein structure by means of the so-called contact maps. The impedance spectra connect the protein morphological transformation, caused by the sensing action, with its change of electrical impedance; the contact maps give complementary information on the structural protein transformations. Our investigations indicate that a change in morphology goes with a change in impedance spectrum and that the size of the variation is in qualitative agreement with existing experiments on these proteins. The present results point to a promising development of a new class of nanobiosensors based on the electrical properties of GPCR and other sensing proteins