title: Does the peroxide compound of cytochrome oxidase contain a ferryl iron?
abstract: The reaction of peroxide with cytochrome oxidase generates a peroxide compound having a Soret maximum at 428 nm. X-ray absorption spectroscopy analysis of the local structure of the active site iron shows marked similarity to that of the cytochrome c peroxidase intermediate Compound ES, which contains a short iron to proximal nitrogen distance compared to globins. Reductive titration of the 580 nm band of this compound indicates that the iron is one oxidizing equivalent above the resting oxidized form. These results support the presence of a ferryl iron (Fe(IV) = O) in the peroxide compound similar to that found for the peroxidases.
authors.affiliation: Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia 19104.
authors.forename: C
authors.initials: C
authors.lastname: Kumar
authors.forename: A
authors.initials: A
authors.lastname: Naqui
authors.forename: L
authors.initials: L
authors.lastname: Powers
authors.forename: Y C
authors.initials: YC
authors.lastname: Ching
authors.forename: B
authors.initials: B
authors.lastname: Chance
mesh_terms: D000818:Animals; D002417:Cattle; D003300:Copper; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005583:Fourier Analysis; D007501:Iron / Q000032:analysis; D008929:Mitochondria, Heart / Q000201:enzymology; D010084:Oxidation-Reduction; D010545:Peroxides / Q000378:metabolism*; D013057:Spectrum Analysis
chemical_list: D010545:Peroxides; D003300:Copper; D007501:Iron; D003576:Electron Transport Complex IV