In Situ Monitoring of the Catalytic Activity of Cytochrome c Oxidase in a Biomimetic Architecture
| Autor: | Wolfgang Knoll, Marcel G. Friedrich, Markus A. Plum, Bernd Ludwig, M. Gabriella Santonicola, Renate L. C. Naumann, Vinzenz U. Kirste |
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| Rok vydání: | 2008 |
| Předmět: |
Biophysics
macromolecular substances Bioenergetics Photochemistry Redox Catalysis Electron Transport Complex IV Biomimetic Materials cytochrome c oxidase Cytochrome c oxidase electron transfer kinetics lipid membrane enzyme immobilization biomimetic materials Lipid bilayer Paracoccus denitrificans biology Chemistry Bilayer Cytochrome c biology.organism_classification Enzymes Immobilized Enzyme Activation biology.protein Cyclic voltammetry |
| Zdroj: | Biophysical Journal. 95(3):1500-1510 |
| ISSN: | 0006-3495 |
| DOI: | 10.1529/biophysj.107.122747 |
| Popis: | Cytochrome c oxidase (CcO) from Paracoccus denitrificans was immobilized in a strict orientation via a his-tag attached to subunit I on a gold film and reconstituted in situ into a protein-tethered bilayer lipid membrane. In this orientation, the cytochrome c (cyt c) binding site is directed away from the electrode pointing to the outer side of the protein-tethered bilayer lipid membrane architecture. The CcO can thus be activated by cyt c under aerobic conditions. Catalytic activity was monitored by impedance spectroscopy, as well as cyclic voltammetry. Cathodic and anodic currents of the CcO with cyt c added to the bulk solution were shown to increase under aerobic compared to anaerobic conditions. Catalytic activity was considered in terms of repeated electrochemical oxidation/reduction of the CcO/cyt c complex in the presence of oxygen. The communication of cyt c bound to the CcO with the electrode is discussed in terms of a hopping mechanism through the redox sites of the enzyme. Simulations supporting this hypothesis are included. |
| Databáze: | OpenAIRE |
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