title: The aerobic reduction of Fe(III) complexes by hemoglobin and myoglobin.
abstract: The ability of hemoglobin (myoglobin) to reduce directly low-molecular-weight complexes of Fe(III) to form methemoglobin (metmyoglobin) and the Fe(II)-tris(2,2'-bipyridine) complex under aerobic conditions is described. The reduction is not mediated by superoxide, O-.2, as shown by increased rates under anaerobic conditions and lack of inhibition by superoxide dismutase. The chemical nature of the Fe(III) complex presented influences the rate of reduction; one of the most effective chelating agents of cellular origin is Fe(III) X ATP. This mechanism may be of fundamental importance in the mobilization and utilization of iron in biological systems.
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives / Q000378:metabolism*; D005296:Ferrous Compounds / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D007700:Kinetics; D008706:Methemoglobin / Q000378:metabolism*; D009211:Myoglobin / Q000378:metabolism*; D010084:Oxidation-Reduction; D011485:Protein Binding; D011725:Pyridines / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D005296:Ferrous Compounds; D009211:Myoglobin; D011725:Pyridines; C024793:tris(2,2'-bipyridyl)-Fe(II) complex; D015082:2,2'-Dipyridyl; D008706:Methemoglobin; D007501:Iron; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase