Enzyme electrokinetics: Hydrogen evolution and oxidation by Allochromatium vinosum [NiFe]-hydrogenase

Christophe Léger, Anne K. Jones, Winfried Roseboom, Simon P.J. Albracht, Fraser A. Armstrong

Research output: Contribution to journalArticle

101 Citations (Scopus)

Abstract

The mechanism of catalytic hydrogen evolution and oxidation by Allochromatium vinosum [NiFe]-hydrogenase has been studied by protein film voltammetry (PFV) with the enzyme adsorbed at a pyrolytic graphite edge electrode. By analyzing the entire shapes of catalytic voltammograms, the energetics of the catalytic cycles (reduction potentials and acidity constants of the active states), including the detailed profiles of activity against pH and the sequences of proton and electron transfers, have been determined, and these are discussed with respect to the mechanism. PFV, which probes rates as a continuous function of the electrochemical potential (i.e., in the "potential domain"), is proven to be an invaluable tool for determining the redox properties of an active site in the presence of its substrate, at room temperature, and during turnover. This is especially relevant in the case of the active states of hydrogenase, since one of its substrates (the proton) is always present at significant levels in the titration medium at physiological pH values.

Original languageEnglish
Pages (from-to)15736-15746
Number of pages11
JournalBiochemistry
Volume41
Issue number52
DOIs
Publication statusPublished - Dec 31 2002

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry

Cite this