This title appears in the Scientific Report :
2003
Please use the identifier:
http://hdl.handle.net/2128/2650 in citations.
Please use the identifier: http://dx.doi.org/10.1073/pnas.1530408100 in citations.
Direct Observation of Protonation Reactions during the Catalytic Cycle of Cytochrome c Oxidase
Direct Observation of Protonation Reactions during the Catalytic Cycle of Cytochrome c Oxidase
Cytochrome c oxidase, the terminal protein in the respiratory chain, converts oxygen into water and helps generate the electrochemical gradient used in the synthesis of ATP. The catalytic action of cytochrome c oxidase involves electron transfer, proton transfer, and O2 reduction. These events trigg...
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Personal Name(s): | Nyquist, R. |
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Heitbrink, D. / Bolwien, C. / Wells, T. A. / Gennis, R. B. / Heberle, J. | |
Contributing Institute: |
Biologische Strukturforschung; IBI-2 |
Published in: | Proceedings of the National Academy of Sciences of the United States of America, 100 (2003) S. 8715 - 8720 |
Imprint: |
Washington, DC
Academy
2003
|
Physical Description: |
8715 - 8720 |
PubMed ID: |
12851460 |
DOI: |
10.1073/pnas.1530408100 |
Document Type: |
Journal Article |
Research Program: |
Neurowissenschaften |
Series Title: |
Proceedings of the National Academy of Sciences of the United States of America
100 |
Subject (ZB): | |
Link: |
Get full text OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1073/pnas.1530408100 in citations.
Cytochrome c oxidase, the terminal protein in the respiratory chain, converts oxygen into water and helps generate the electrochemical gradient used in the synthesis of ATP. The catalytic action of cytochrome c oxidase involves electron transfer, proton transfer, and O2 reduction. These events trigger specific molecular changes at the active site, which, in turn, influence changes throughout the protein, including alterations of amino acid side chain orientations, hydrogen bond patterns, and protonation states. We have used IR difference spectroscopy to investigate such modulations for the functional intermediate states E, R2,Pm, and F. These spectra reveal deprotonation of its key glutamic acid E286 in the E and in the Pm states. The consecutive deprotonation and reprotonation of E286 twice within one catalytic turnover illustrates the role of this residue as a proton shuttle. In addition, the spectra point toward deprotonation of a redox-active tyrosine, plausibly Y288, in the F intermediate. Structural insights into the molecular mechanism of catalysis based on the subtle molecular changes observed with IR difference spectroscopy are discussed. |