Difference between revisions of "Catalase"

Revision as of 11:56, 15 April 2014

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Catalase

Description

Catalase catalyzes the dismutation of hydrogen peroxide to water and oxygen.

Abbreviation: Ctl

Reference: MiPNet09.12

MitoPedia topics: Enzyme

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.

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.

@@ Line 13: / Line 13: @@
 == Application in [[HRR]]  ==
-'''Clt: Catalase''' (from bovine liver,lyophilized powder, 2.000-5.000 units/mg protein); Sigma C 9322, store at -20 °C
+'''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 [[MiPNet14.13_Medium-MiR06 | 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 H<sub>2</sub>O<sub>2</sub>.
@@ Line 19: / Line 19: @@
 === Preparation of catalase stock solution ===
-::'''Stock solution:''' 112.000 U/ml (dissolved in MiR05)
+::'''Stock solution:''' 112,000 U/ml (dissolved in MiR05)
-::'''Example:''' 'Catalase lypophilized powder, 2800 units/mg solid and 3500 units/mg protein'
+::'''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 (2800 U/mg) are dissolved in 1 ml MiR05 to obtain a catalase stock solution with 112.000 U/ml.
+::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.
@@ Line 30: / Line 30: @@
-'''Oxygraph-2k manual titrations:''' [[MiPNet09.12]]
+'''Oxygraph-2k manual titrations''' [[MiPNet09.12 O2k-Titrations]]
-::* Titration volume: 5 µl Ctl using a 25 µl syringe
+::* Titration volume: 5 µl Ctl using a 25 µl syringe (2 ml O2k-chamber).
-::* Final conc. in 2 ml O2k-chamber: 280 U/ml
+::* Final concentration: 280 U/ml.