X‐ray absorption edge studies on cyanide‐bound cytochrome <i>c</i> oxidase

Hu, Valerie W.; Chan, Sunney I.

doi:10.1016/0014-5793(77)80708-4

Cited by 21 publications

(1 citation statement)

References 16 publications

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“…Early experiments were performed by Hu, Chan, and Brown, who concluded from the shape and position ofthe edge that one copper ofthe resting enzyme was actually in the reduced [Cu(I)] form (9). Hu et al, also investigated the effects ofcyanide treatment on the iron and copper absorption edges, finding no change in the copper edge of either the -oxidized or the dithionite-reduced sample (10). Later work was done by Powers and coworkers (11), who disputed the previous Cu(I) assignment and attributed some findings ofthe work by Hu et al., to adventitious copper and photoreduction.…”

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confidence: 99%

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

Scott

Cramer

Shaw

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

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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 Å and the average Cu—N (or Cu—O) distance is 1.97 ± 0.02 Å. The amplitudes require ca , 1-1.5 sulfurs and 2 nitrogens (or oxygens) per copper. The distribution of sulfur ligands between Cu A and Cu B sites is not known, although there is some evidence that two sulfur atoms are bound to Cu A .

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confidence: 99%