[NiFe] hydrogenases: structural and spectroscopic studies of the reaction mechanism.
[NiFe] hydrogenases catalyze the reversible oxidation of dihydrogen. For this simple reaction the molecule has developed a complex catalytic mechanism, during which the enzyme passes through various redox states. The [NiFe] hydrogenase contains several metal centres, including the bimetallic Ni-Fe active site, iron-sulfur clusters and a Mg(2+) ion. The Ni-Fe active site is located in the inner part of the protein molecule, therefore a number of pathways are involved in the catalytic reaction route. These consist of an electron transfer pathway, a proton transfer pathway and a gas-access channel. Over the last 10-15 years we have been investigating the crystal structures of the [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F, which is a sulfate-reducing anaerobic bacterium. So far the crystal structures of the oxidized, H(2)-reduced and carbon monoxide inhibited states have been determined at high resolution and have revealed a rather unique structure of the hetero-bimetallic Ni-Fe active site. Furthermore, intensive spectroscopic studies have been performed on the enzyme. Based on the crystal structure, a water-soluble Ni-Ru complex has been synthesized as a functional model for the [NiFe] hydrogenases. The present review gives an overview of the catalytic reaction mechanism of the [NiFe] hydrogenases.
Ogata
Hideaki
H
Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470, Mülheim an der Ruhr, Germany.
Lubitz
Wolfgang
W
Higuchi
Yoshiki
Y
D055162:Biocatalysis; D002248:Carbon Monoxide / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006864:Hydrogenase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D010084:Oxidation-Reduction; D013057:Spectrum Analysis
D004791:Enzyme Inhibitors; D002248:Carbon Monoxide; C043296:nickel-iron hydrogenase; D006864:Hydrogenase