A network model to investigate structural and electrical properties of proteins

TL;DR

This paper introduces an impedance network model to analyze how conformational changes in proteins like rhodopsin and AChE affect their electrical properties, aiding in the development of bioelectronic devices.

Contribution

The study presents a novel impedance network model that can detect protein conformational changes through electrical response analysis, advancing molecular electronics research.

Findings

Rhodopsin shows a stronger electrical differential response than AChE.

The model can monitor structural and conformational changes in proteins.

Supports hypothesis of a mixed native state in proteins.

Abstract

One of the main trend in to date research and development is the miniaturization of electronic devices. In this perspective, integrated nanodevices based on proteins or biomolecules are attracting a major interest. In fact, it has been shown that proteins like bacteriorhodopsin and azurin, manifest electrical properties which are promising for the development of active components in the field of molecular electronics. Here we focus on two relevant kinds of proteins: The bovine rhodopsin, prototype of GPCR protein, and the enzyme acetylcholinesterase (AChE), whose inhibition is one of the most qualified treatments of Alzheimer disease. Both these proteins exert their functioning starting with a conformational change of their native structure. Our guess is that such a change should be accompanied with a detectable variation of their electrical properties. To investigate this conjecture, we present an impedance network model of proteins, able to estimate the different electrical response associated with the different configurations. The model resolution of the electrical response is found able to monitor the structure and the conformational change of the given protein. In this respect, rhodopsin exhibits a better differential response than AChE. This result gives room to different interpretations of the degree of conformational change and in particular supports a recent hypothesis on the existence of a mixed state already in the native configuration of the protein.