One of two copper atoms is not necessary for the cytochrome c oxidase activity of Pseudomonas AM 1 cytochrome aa3.
From Pseudomonas AM 1 grown in a medium deficient in Cu, aa3-type cytochrome c oxidase was purified which contained 2 molecules of haem a and one atom of Cu per molecule. The enzyme showed absorption peaks at 428 and 595 nm in the oxidized form and at 442 and 604 nm in the reduced form, and its CO complex showed peaks at 432 and 602 nm. The enzyme in the oxidized state showed an obscure absorption peak around 800 nm instead of a peak at 820 nm. One mol of the enzyme oxidized maximally 76, 75, and 98 mol of the ferrocytochromes c of Candida krusei, horse and Pseudomonas AM 1 per sec, respectively. These reactions were 50% inhibited by 7 microM KCN. The product of reduction of O2 catalyzed by the enzyme was concluded to be H2O on the basis of the ratio of ferrocytochrome c oxidized to O2 consumed.
D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D002175:Candida / Q000201:enzymology; D003300:Copper / Q000502:physiology*; D003574:Cytochrome c Group / Q000378:metabolism; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D006418:Heme / Q000378:metabolism; D006736:Horses / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology*; D013055:Spectrophotometry, Infrared
D001426:Bacterial Proteins; D003574:Cytochrome c Group; D005656:Fungal Proteins; D006418:Heme; D003300:Copper; D003576:Electron Transport Complex IV; D010100:Oxygen