X-Ray Absorption Edge Studies on Oxidized and Reduced Cytochrome c Oxidase
The x-ray absorption edge spectra of the Cu and Fe centers in oxidized and reduced cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase; EC 1.9.3.1) have been obtained using synchrotron radiation from the SPEAR storage ring at the Stanford Linear Accelerator Center. In addition, oxidized an...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 74; no. 9; pp. 3821 - 3825 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences of the United States of America
01.09.1977
National Acad Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | The x-ray absorption edge spectra of the Cu and Fe centers in oxidized and reduced cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase; EC 1.9.3.1) have been obtained using synchrotron radiation from the SPEAR storage ring at the Stanford Linear Accelerator Center. In addition, oxidized and reduced plastocyanin as well as a number of model copper compounds in various oxidation states were also examined. A comparison of the absorption edge fine structure of cytochrome oxidase with those of the models indicates that one of the two coppers in the oxidized protein is in the + 1 oxidation state. Upon reduction of the protein with dithionite, the second copper becomes Cu(I). The shift in the Fe K-edge of cytochrome oxidase upon reduction is small (about 2 eV or 3 × 10-19J) and is comparable to that previously observed for the reduction of the heme iron of cytochrome c. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.74.9.3821 |