Reduction Potentials of [FeFe]-Hydrogenase Accessory Iron-Sulfur Clusters Provide Insights into the Energetics of Proton Reduction Catalysis
| Autor: | Jacob H. Artz, S. Garrett Williams, Anne K. Jones, Paul W. King, Michael W. Ratzloff, John W. Peters, Oleg A. Zadvornyy, David W. Mulder, Carolyn E. Lubner, Axl X. LeVan, Michael W. W. Adams |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Iron-Sulfur Proteins Hydrogenase Proton Electron donor 010402 general chemistry Electrochemistry 01 natural sciences Biochemistry Catalysis law.invention 03 medical and health sciences chemistry.chemical_compound Colloid and Surface Chemistry Computational chemistry law Cluster (physics) Electron paramagnetic resonance Clostridium biology Chemistry Electron Spin Resonance Spectroscopy Active site General Chemistry 0104 chemical sciences Molecular Docking Simulation Crystallography 030104 developmental biology biology.protein Biocatalysis Potentiometry Thermodynamics Protons Oxidation-Reduction |
| Zdroj: | Journal of the American Chemical Society. 139(28) |
| ISSN: | 1520-5126 |
| Popis: | An [FeFe]-hydrogenase from Clostridium pasteurianum, CpI, is a model system for biological H2 activation. In addition to the catalytic H-cluster, CpI contains four accessory iron–sulfur [FeS] clusters in a branched series that transfer electrons to and from the active site. In this work, potentiometric titrations have been employed in combination with electron paramagnetic resonance (EPR) spectroscopy at defined electrochemical potentials to gain insights into the role of the accessory clusters in catalysis. EPR spectra collected over a range of potentials were deconvoluted into individual components attributable to the accessory [FeS] clusters and the active site H-cluster, and reduction potentials for each cluster were determined. The data suggest a large degree of magnetic coupling between the clusters. The distal [4Fe-4S] cluster is shown to have a lower reduction potential (∼ |
| Databáze: | OpenAIRE |
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