title: Cytochrome c peroxidase from Methylococcus capsulatus Bath.
abstract: A bacterial cytochrome c peroxidase was purified from the obligate methanotroph Methylococcus capsulatus Bath in either the fully oxidized or the half reduced form depending on the purification procedure. The cytochrome was a homo-dimer with a subunit mol mass of 35.8 kDa and an isoelectric point of 4.5. At physiological temperatures, the enzyme contained one high-spin, low-potential (Em7 = -254 mV) and one low-spin, high-potential (Em7 = +432 mM ) heme. The low-potential heme center exhibited a spin-state transition from the penta-coordinated, high-spin configuration to a low-spin configuration upon cooling the enzyme to cryogenic temperatures. Using M. capsulatus Bath ferrocytochrome c555 as the electron donor, the KM and Vmax for peroxide reduction were 510 +/- 100 nM and 425 +/- 22 mol ferrocytochrome c555 oxidized min-1 (mole cytochrome c peroxidase)-1, respectively.
authors.affiliation: Department of Microbiology, Immunology, and Preventive Medicine, Iowa State University, 207 Science Building I, Ames, IA 50011-3211, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Zahn
authors.forename: D M
authors.initials: DM
authors.lastname: Arciero
authors.forename: A B
authors.initials: AB
authors.lastname: Hooper
authors.forename: J R
authors.initials: JR
authors.lastname: Coats
authors.forename: A A
authors.initials: AA
authors.lastname: DiSpirito
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D003574:Cytochrome c Group / Q000737:chemistry; D003578:Cytochrome-c Peroxidase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006418:Heme / Q000032:analysis; D007526:Isoelectric Point; D007700:Kinetics; D008772:Methylococcaceae / Q000201:enzymology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
chemical_list: D000596:Amino Acids; D003574:Cytochrome c Group; D004791:Enzyme Inhibitors; D006418:Heme; D003578:Cytochrome-c Peroxidase