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Radi 1991 J Biol Chem

From Bioblast
Publications in the MiPMap
Radi R, Turrens JF, Chang LY, Bush KM, Crapo JD, Freeman BA (1991) Detection of catalase in rat heart mitochondria. J Biol Chem 266:22028-34.

ยป PMID: 1657986 Open Access

Radi R, Turrens JF, Chang LY, Bush KM, Crapo JD, Freeman BA (1991) J Biol Chem

Abstract: The presence of heme-containing catalase in rat heart mitochondria (20 +/- 5 units/mg) was demonstrated by biochemical and immunocytochemical analysis. Intact rat heart mitochondria efficiently consumed exogenously added H2O2. The rate of H2O2 consumption was not influenced by succinate, glutamate/malate, or N-ethylmaleimide but was significantly inhibited by cyanide. Hydrogen peroxide decomposition by mitochondria yielded molecular oxygen in a 2:1 stoichiometry, consistent with a catalytic mechanism. Mitochondrial fractionation studies and quantitative electron microscopic immunocytochemistry revealed that most catalase was matrix-associated. Electrophoretic analysis and Western blotting of the mitochondrial matrix fraction indicated the presence of a protein with similar electrophoretic mobility to bovine and rat liver catalase and immunoreactive to anti-catalase antibody. Myocardial tissue has a lower catalase-specific activity and a greater mitochondrial H2O2 production/g of tissue than most organs. Thus catalase, representing 0.025% of heart mitochondrial protein, is important for detoxifying mitochondrial derived H2O2 and represents a key antioxidant defense mechanism for myocardial tissue. โ€ข Keywords: Catalase

โ€ข O2k-Network Lab: UY Montevideo Radi R


Stress:Oxidative stress;RONS  Organism: Rat  Tissue;cell: Heart