Abstract
Potentiometric titrations of the cytochrome c oxidase (CcO) immobilized in a biomimetic membrane system were followed by two-dimensional surface-enhanced IR absorption spectroscopy (2D SEIRAS) in the ATR-mode. Direct electron transfer was employed to vary the redox state of the enzyme. The CcO was shown to undergo a conformational transition from a non-activated to an activated state after it was allowed to turnover in the presence of oxygen. Differences between the non-activated and activated state were revealed by 2D SEIRA spectra recorded as a function of potential. The activated state was characterized by a higher number of correlated transitions as well as a higher number of amino acids associated with electron transfer.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acids / chemistry
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Amino Acids / metabolism
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Bacterial Proteins / chemistry*
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Bacterial Proteins / metabolism
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Crystallography, X-Ray
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Electrochemical Techniques / methods*
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Electron Transport
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Electron Transport Complex IV / chemistry*
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Electron Transport Complex IV / metabolism
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Enzyme Activation
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Hydrophobic and Hydrophilic Interactions
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Models, Molecular
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Oxidation-Reduction
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Oxygen / chemistry
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Oxygen / metabolism
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Protein Conformation*
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Protein Subunits / chemistry
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Protein Subunits / metabolism
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Rhodobacter sphaeroides / enzymology
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Spectroscopy, Fourier Transform Infrared / methods*
Substances
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Amino Acids
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Bacterial Proteins
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Protein Subunits
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Electron Transport Complex IV
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Oxygen