Photochemical generation and reactions of heme cation radicals in heme proteins.
A novel approach is described for generating reactive oxidizing centers in heme proteins, with zinc hemoglobin (Zn Hb) and zinc cytochrome c (Zn cyt c) used as examples. The reaction of 3Zn* Hb with [CoIII(NH3)5 Cl]2+, and of 3Zn* cyt c with methyl viologen are described. In the case of Zn Hb the cation radical produced decays with a rate constant of k3 = 2400s-1. Using this value the rate of the reaction (formula; see text) can be calculated to be 4500s-1.
Magner
E
E
Department of Chemistry, University of Rochester, NY 14627.
McLendon
G
G
D003574:Cytochrome c Group; D004579:Electron Transport; D005609:Free Radicals; D006418:Heme; D006420:Hemeproteins; D006454:Hemoglobins; D007700:Kinetics; D008665:Metalloporphyrins; D010084:Oxidation-Reduction; D010782:Photolysis; D015032:Zinc
D003574:Cytochrome c Group; D005609:Free Radicals; D006420:Hemeproteins; D006454:Hemoglobins; D008665:Metalloporphyrins; C052598:zinc hemoglobin; C017802:zinc hematoporphyrin; D006418:Heme; D015032:Zinc