title: Thiobacillus novellus cytochrome c oxidase contains one heme alpha molecule and one copper atom per catalytic unit.
abstract: The minimal structural unit of cytochrome c oxidase purified from Thiobacillus novellus was composed of one molecule each of two subunits with molecular masses of 32 and 23 kDa, respectively, and the unit had one molecule of heme a and one atom of copper. In the presence of n-octyl-beta-D-thioglucoside, the oxidase existed as the monomeric form of the unit, while it occurred as the dimeric form of the unit in the presence of Tween 20. The monomeric form showed an active cytochrome c oxidizing activity and reduced molecular oxygen to water with ferrocytochrome c. Namely, it has been shown that the bacterial cytochrome c oxidase with one heme a molecule and one copper atom per molecule can catalyze oxidation of ferrocytochrome c with concomitant reduction of molecular oxygen to water.
authors.affiliation: Department of Life Science, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Kanagawa.
authors.forename: K
authors.initials: K
authors.lastname: Shoji
authors.forename: T
authors.initials: T
authors.lastname: Yamazaki
authors.forename: T
authors.initials: T
authors.lastname: Nagano
authors.forename: Y
authors.initials: Y
authors.lastname: Fukumori
authors.forename: T
authors.initials: T
authors.lastname: Yamanaka
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D002850:Chromatography, Gel; D003300:Copper / Q000032:analysis*; D003574:Cytochrome c Group / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006418:Heme / Q000032:analysis*; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D013053:Spectrophotometry
chemical_list: D003574:Cytochrome c Group; D006418:Heme; D003300:Copper; D003576:Electron Transport Complex IV