The role of O2.- in the production of HO.: in vitro and in vivo.
In vitro O2.- reduces Fe(III) to Fe(II), which, in turn, reduces the H2O2, yielding Fe(II)O or HO.. In vivo O2.- increases the supply of free iron by oxidatively attacking the [4Fe-4S] clusters of dehydratases such that they release Fe(II), which can then reduce H2O2. In vivo, O2.- also increases the production of H2O2 by acting as an oxidant toward the dehydratases and toward other cellular reductants.
Liochev
S I
SI
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Fridovich
I
I
D000154:Aconitate Hydratase / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D005609:Free Radicals; D006836:Hydro-Lyases / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000494:pharmacology*
D005296:Ferrous Compounds; D005609:Free Radicals; D007506:Iron-Sulfur Proteins; D013481:Superoxides; D017665:Hydroxyl Radical; D009249:NADP; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D006836:Hydro-Lyases; D000154:Aconitate Hydratase