title: Current-voltage characteristics of seven-helix proteins from a cubic array of amino acids.
abstract: The electrical properties of a set of seven-helix transmembrane proteins, whose space arrangement [three-dimensional (3D) structure] is known, are investigated by using regular arrays of the amino acids. These structures, specifically cubes, have topological features similar to those shown by the chosen proteins. The theoretical results show a good agreement between the predicted current-voltage characteristics obtained from a cubic array and those obtained from a detailed 3D structure. The agreement is confirmed by available experiments on bacteriorhodopsin. Furthermore, all the analyzed proteins are found to share the same critical behavior of the voltage-dependent conductance and of its variance. In particular, the cubic arrangement evidences a short plateau of the excess conductance and its variance at high voltages. The results of the present investigation show the possibility to predict the I-V characteristics of a multiple-protein sample even in the absence of detailed knowledge of the proteins' 3D structure.
authors.affiliation: Dipartimento di Ingegneria dell'Innovazione, Università del Salento, via Monteroni, I-73100 Lecce, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Alfinito
authors.affiliation: Dipartimento di Matematica e Fisica, "Ennio de Giorgi," Università del Salento, via Monteroni, I-73100 Lecce, Italy.
authors.forename: Lino
authors.initials: L
authors.lastname: Reggiani
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D055724:Electrophysiological Phenomena; D008565:Membrane Proteins / Q000737:chemistry*; D008962:Models, Theoretical; D017434:Protein Structure, Tertiary
chemical_list: D000596:Amino Acids; D008565:Membrane Proteins