A comparison of catalytic site intermediates of cytochrome c oxidase and peroxidases.
Compounds I and II of peroxidases such as horseradish peroxidase and cytochrome c peroxidase are relatively well understood catalytic intermediates in terms of their structures and redox states of iron, heme, and associated radical species. The intermediates involved in the oxygen reduction chemistry of the cytochrome c oxidase superfamily are more complicated because of the need for four reducing equivalents and because of the linkage of the oxygen chemistry with vectorial proton translocations. Nevertheless, two of these intermediates, the peroxy and ferryl forms, have characteristics that can in many ways be considered to be counterparts of peroxidase compounds I and II. We explore the primary factors that minimize the generation of unwanted reactive oxygen species products and ensure that the principal enzymological function becomes either that of a peroxidase or an oxidase. These comparisons can provide insights into the nature of biological oxygen reduction chemistry and guidance for the engineering of biomimetic synthetic materials.
Rich
P R
PR
Glynn Laboratory of Bioenergetics, Department of Biology, University College London, London WC1E 6BT, UK. prr@ucl.ac.uk
Iwaki
M
M
D000818:Animals; D001669:Biochemical Phenomena; D001671:Biochemistry; D032701:Biomimetics; D002384:Catalysis; D020134:Catalytic Domain; D004563:Electrochemistry / Q000379:methods; D003576:Electron Transport Complex IV / Q000737:chemistry*; D006801:Humans; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010544:Peroxidases / Q000737:chemistry*; D021381:Protein Transport; D017382:Reactive Oxygen Species; D013053:Spectrophotometry / Q000379:methods
D017382:Reactive Oxygen Species; D010544:Peroxidases; D003576:Electron Transport Complex IV; D010100:Oxygen