Topological change and impedance spectrum of rat olfactory receptor I7: A comparative analysis with bovine rhodopsin and bacterior

TL;DR

This study models the impedance spectrum changes in rat olfactory receptor I7 upon activation, comparing it with bovine rhodopsin and bacteriorhodopsin, suggesting potential for novel nanobiosensors based on GPCR electrical properties.

Contribution

It introduces a theoretical model linking protein morphological changes to impedance spectra, advancing the understanding of GPCR-based sensing mechanisms.

Findings

Impedance decreases by up to 60% upon receptor activation.

Model predictions align with experimental data on rat OR I7.

Successful validation with bacteriorhodopsin experiments.

Abstract

We present a theoretical investigation on possible selection of olfactory receptors (ORs) as sensing components of nanobiosensors. Accordingly, we generate the impedance spectra of the rat OR I7 in the native and activated state and analyze their differences. In this way, we connect the protein morphological transformation, caused by the sensing action, with its change of electrical impedance. The results are compared with those obtained by studying the best known protein of the GPCR family: bovine rhodopsin. Our investigations indicate that a change in morphology goes with a change in impedance spectrum mostly associated with a decrease of the static impedance up to about 60 % of the initial value, in qualitative agreement with existing experiments on rat OR I7. The predictiveness of the model is tested successfully for the case of recent experiments on bacteriorhodopsin. 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.