TY - JOUR
T1 - Enzyme electrokinetics
T2 - Hydrogen evolution and oxidation by Allochromatium vinosum [NiFe]-hydrogenase
AU - Léger, Christophe
AU - Jones, Anne K.
AU - Roseboom, Winfried
AU - Albracht, Simon P.J.
AU - Armstrong, Fraser A.
PY - 2002/12/31
Y1 - 2002/12/31
N2 - 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.
AB - 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.
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U2 - 10.1021/bi026586e
DO - 10.1021/bi026586e
M3 - Article
C2 - 12501202
AN - SCOPUS:0037207118
SN - 0006-2960
VL - 41
SP - 15736
EP - 15746
JO - Biochemistry
JF - Biochemistry
IS - 52
ER -