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Bioblasts - Richard Altmann and MiPArt by Odra Noel
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Catalase catalyzes the dismutation of hydrogen peroxide to water and oxygen. Perhaps all cells have catalase, but mitochondria of most cells lack catalase. Cardiac mitochondria are exceptional in having mt-catalase activity (rat heart mitochondria: Radi et al 1991; mouse heart mitochondria: Rindler et al 2013).

Abbreviation: Ctl

Reference: Radi 1991 J Biol Chem, Rindler 2013 J Biol Chem, MiPNet09.12

MitoPedia topics: Enzyme 

Communicated by Gnaiger E (2015-03-05).

Application in HRR

Clt: Catalase (from bovine liver, lyophilized powder; 2,000-5,000 U/mg protein); Sigma C 9322; store at -20 °C.

Catalase is included in the mitochondrial respiration medium MiR06 (MiR06 = MiR05 plus catalase), so as to allow for re-oxygenation of the respiration medium (without lifting the stopper and risking the introduction of air bubbles) by addition of a small volume of a 200 mM stock solution of H2O2.

Preparation of catalase stock solution

Stock solution: 112,000 U/mL (dissolved in MiR05)
Example: 'Catalase lypophilized powder; 2,800 U/mg solid and 3,500 units/mg protein'
1) Use 'units/mg solid' for your calculations
2) Result: 40 mg catalase powder (2,800 U/mg) are dissolved in 1 mL MiR05 to obtain a catalase stock solution with 112,000 U/mL.
3) Divide into 0.2 mL portions.
4) Store frozen at -20 °C.

Unit definition: * Units of enzymatic activity (U) in µmol/min; assay used by Sigma Aldrich: ' One unit will decompose 1.0 μmole of H2O2 per min at pH 7.0 at 25 °C, while the H2O2 concentration falls from 10.3 to 9.2 mM, measured by the rate of decrease of A240. '

Oxygraph-2k manual titrations MiPNet09.12 O2k-Titrations

  • Titration volume: 5 µL Ctl using a 25 µL syringe (2 mL O2k-chamber).
  • Final concentration: 280 U/mL.