Diazene--a not so innocent ligand for the binuclear center of cytochrome c oxidase.
Diazene reacts rapidly with cytochrome c oxidase to reduce cytochrome a and CuA and to form a charge-transfer complex with ferric cytochrome a3; the diazene may serve to bridge the heme iron of this cytochrome and CuB. The complex is characterized by an intense, optically active absorbance located at 847 nm. A similar band had been observed previously upon reduction of cytochrome oxidase with hydrazine [Markossian, K. A., Paitian, N. A., and Nalbandyan, R. M. (1983) FEBS Lett. 156, 235-238], but it appears that this band is actually due to the diazene produced as a result of the oxidation of the hydrazine that occurs in this process. A similar diazene to iron charge-transfer band is found following the reaction of diazene with ferric horseradish peroxidase and with hemin chloride but not with met-myoglobin.
Liao
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Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005-1892, USA.
Palmer
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D000818:Animals; D002417:Cattle; D004578:Electron Spin Resonance Spectroscopy; D003576:Electron Transport Complex IV / Q000737:chemistry* / Q000378:metabolism; D006418:Heme / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry; D007094:Imides / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D009211:Myoglobin / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen; D011190:Potassium Cyanide / Q000737:chemistry; D013053:Spectrophotometry
D006834:Hydrazines; D007094:Imides; D008024:Ligands; D009211:Myoglobin; C029424:hydrazine; D006418:Heme; D006735:Horseradish Peroxidase; D003576:Electron Transport Complex IV; C038867:diazene; D011190:Potassium Cyanide; D010100:Oxygen