Extended x-ray absorption fine structure of copper in cytochrome c oxidase: Direct evidence for copper-sulfur ligation

Creators: Scott, Robert A.; Cramer, Stephen P.; Shaw, Robert W.; Beinert, Helmut; Gray, Harry B.

Abstract

The copper x-ray fluorescence excitation spectrum of cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) has been recorded in the 245-270 K range. The beat pattern observed in the extended x-ray absorption fine structure can be accounted for only by postulating a combination of sulfur and nitrogen (or oxygen) ligands to the copper. The average Cu-S distance is 2.27± 0.02 angstrom and the average Cu-N (or Cu-O) distance is 1.97± 0.02 angstrom. The amplitudes require ca. 1-1.5 sulfurs and 2 nitrogens (or oxygens) per copper. The distribution of sulfur ligands between CuA and CuB sites is not known, although there is some evidence that two sulfur atoms are bound to CuA.

Additional Information

Copyright © 1981 by the National Academy of Sciences. Contributed by Harry B. Gray, August 25, 1980. We thank Drs. Sunney Chan, Keith Hodgson, and Bo Malmstrom for helpful discussions. We thank the staffs of the Stanford Synchrotron Radiation Laboratory (especially Robert Filippi) and of the Stanford Linear Accelerator Center (especially Robert Mason) for assistance in equipment design and experimental execution. R.A.S. acknowledges a National Institutes of Health Fellowship (1-F32-HL06047-01). Experiments at the Stanford Synchrotron Radiation Laboratory were supported by National Science Foundation Grant DMR-07692-A02 in cooperation with the Stanford Linear Accelerator Center and the Department of Energy. Research at the Institute for Enzyme Research was supported by National Institutes of Health Grant GM-12394. H.B. acknowledges a Research Career Award (S-K06-GM-18442). R.W.S. acknowledges a National Institutes of Health Fellowship (S F32 GM05772-02) and a National Institute of Arthritis, Metabolism, and Digestive Diseases Postdoctoral Training Grant (2 T32 AM07049-07). Research at the California Institute of Technology was supported by National Science Foundation Grant CHE77-11389. This is contribution no. 6295 from the Arthur Amos Noyes Laboratory. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

Files

SCOpnas81.pdf

Files (710.0 kB)

Name	Size	Download all
SCOpnas81.pdf md5:5aa3f0e1d9e23cedecbbdb4f8519de5c	710.0 kB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes