title: O2Activation by Non-Heme Iron Enzymes.
abstract: The non-heme Fe enzymes are ubiquitous in nature and perform a wide range of functions involving O2activation. These had been difficult to study relative to heme enzymes; however, spectroscopic methods that provide significant insight into the correlation of structure with function have now been developed. This Current Topics article summarizes both the molecular mechanism these enzymes use to control O2activation in the presence of cosubstrates and the oxygen intermediates these reactions generate. Three types of O2activation are observed. First, non-heme reactivity is shown to be different from heme chemistry where a low-spin FeIII-OOH non-heme intermediate directly reacts with substrate. Also, two subclasses of non-heme Fe enzymes generate high-spin FeIV═O intermediates that provide both σ and π frontier molecular orbitals that can control selectivity. Finally, for several subclasses of non-heme Fe enzymes, binding of the substrate to the FeIIsite leads to the one-electron reductive activation of O2to an FeIII-superoxide capable of H atom abstraction and electrophilic attack.
authors: Department of Chemistry, Stanford University , Stanford, California 94305, United States.|SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Edward I
authors: EI
authors: Solomon
authors: Department of Chemistry, Stanford University , Stanford, California 94305, United States.
authors: Serra
authors: S
authors: Goudarzi
authors: Department of Chemistry, Stanford University , Stanford, California 94305, United States.
authors: Kyle D
authors: KD
authors: Sutherlin
mesh_terms: D020134:Catalytic Domain; D002942:Circular Dichroism / Q000379:methods; D049308:Dioxygenases / Q000737:chemistry* / Q000378:metabolism; D004798:Enzymes / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D019159:Nonheme Iron Proteins / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D004798:Enzymes; D019159:Nonheme Iron Proteins; D049308:Dioxygenases; D010100:Oxygen