title: Interaction of p-phenylenediamine with the iron-bleomycin complex.
abstract: The iron-bleomycin complex has been shown to catalyze the oxidation of p-phenylenediamine to a stable, purple coloured oxidation product, characterized by an absorption maximum around 520 nm. Molecular oxygen is used for reoxidizing Fe(II)-bleomycin after reduction by p-phenylenediamine. An apparent Michaelis constant of 5.2 mM and a catalytic constant of 17.2 min-1 were obtained from kinetic studies. ATP, ADP and orthophosphate inhibited the catalytic oxidation of p-phenylenediamine, while AMP was without effect. It is proposed that p-phenylenediamine may be used as 'substrate' in kinetic studies involving the 'oxidase' activity of iron-bleomycin.
authors.affiliation: Department of Medical Biochemistry, University of Oslo, Norway.
authors.forename: R A
authors.initials: RA
authors.lastname: Løvstad
mesh_terms: D001761:Bleomycin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D004396:Coloring Agents / Q000737:chemistry; D004347:Drug Interactions; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D010655:Phenylenediamines / Q000737:chemistry / Q000378:metabolism*; D010710:Phosphates / Q000737:chemistry; D013997:Time Factors
chemical_list: D004396:Coloring Agents; D010655:Phenylenediamines; D010710:Phosphates; C023503:iron bleomycin; D001761:Bleomycin; D007501:Iron; C029728:4-phenylenediamine