Electrochemical studies on small electron transfer proteins using membrane electrodes

M. M. Correia dos Santos, P. M. Paes de Sousa, M. L. Simões Gonçalves, L. Krippahl, J. J.G. Moura, É Lojou, P. Bianco

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Membrane electrodes (ME) were constructed using gold, glassy carbon and pyrolytic graphite supports and a dialysis membrane, and used to study the electrochemical behavior of small size electron transfer proteins: monohemic cytochrome c522 from Pseudomonas nautica and cytochrome c533 as well as rubredoxin from Desulfovibrio vulgaris. Different electrochemical techniques were used including cyclic voltammetry (CV), square wave voltammetry (SW) and differential pulse voltammetry (DP). A direct electrochemical response was obtained in all cases except with rubredoxin where a facilitator was added to the protein solution entrapped between the membrane and the electrode surface. Formal potentials and heterogeneous charge transfer rate constants were determined from the voltammetric data. The influence of the ionic strength and the pH of the medium on the electrochemical response at the ME were analyzed. The benefits from the use of the ME in protein electrochemistry and its role in modulating the redox behavior are analyzed. A critical comparison is presented with data obtained at non-MEs. Finally, the interactions that must be established between the proteins and the electrode surfaces are discussed, thereby modeling molecular interactions that occur in biological systems.

Original languageEnglish
Pages (from-to)153-162
Number of pages10
JournalJournal Of Electroanalytical Chemistry
Volume541
DOIs
Publication statusPublished - 16 Jan 2003

Keywords

  • Cytochromes c and c
  • Membrane electrodes
  • Rubredoxin
  • Unmediated electrochemistry

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