Volume 85, Number 6, March 2009
Article Number 68002
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 01 April 2009
EPL, 85 (2009) 68002
DOI: 10.1209/0295-5075/85/68002

Charge transport in bacteriorhodopsin monolayers: The contribution of conformational change to current-voltage characteristics

E. Alfinito1, 2 and L. Reggiani1, 2

1   Dipartimento di Ingegneria dell'Innovazione, Università del Salento - via Arnesano, I-73100 Lecce, Italy, EU
2   CNISM, Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia via della Vasca Navale 84, I-00146 Roma, Italy, EU

received 13 November 2008; accepted in final form 23 February 2009; published March 2009
published online 1 April 2009

When moving from native to light-activated bacteriorhodospin, modification of charge transport consisting of an increase of conductance is correlated to the protein conformational change. A theoretical model based on a map of the protein tertiary structure into a resistor network is implemented to account for a sequential tunneling mechanism of charge transfer through neighbouring amino acids. The model is validated by comparison with current-voltage experiments. The predictability of the model is further tested on bovine rhodopsin, a G-protein coupled receptor (GPCR) also sensitive to light. In this case, results show an opposite behaviour with a decrease of conductance in the presence of light.

87.85.jc - Electrical, thermal, and mechanical properties of biological matter.
87.15.hp - Conformational changes.
87.10.Rt - Monte Carlo simulations.

© EPLA 2009