Catalase from bovine liver aqueous suspension, 40,000-60,000 units/mg protein (E1%/405)

Synonym: H₂O₂:H₂O₂ oxidoreductase

CAS Number: 9001-05-2

Enzyme Commission (EC) Number: 1.11.1.6

MDL Number: MFCD00081483

eCl@ss: 32160410

Components
Catalase from bovine liver is a tetramer consisting of 4 equal subunits each with a 60 kDa molecular weight. Each of these subunits contains iron bound to a protoheme IX group. The enzyme will also strongly bind to NADP, where NADP and the heme group are within 13.7 angstroms.

Application
Catalase acts as a natural antioxidant to study the roles of reactive oxygen species in gene expression and apoptosis. It has also been used to protect against oxidative damage to proteins, lipids, and nucleic acids. Industrially, catalses have been used to remove hydrogen peroxide added to milk and cheese, in textile bleaching, and to examine its positive effects on the viability of DNA-repair mutants of E. coli.

Biochem/physiol Actions
Catalase catalyzes the degradation of hydrogen peroxide into water and oxygen. It can also react with alkylhydrogen peroxides, such as methylperoxide and ethylperoxide and the second H2O2 molecule can be replaced by methanol, ethanol, propanol, formate and nitrate as a hydrogen donor.

Caution
Solutions of catalse should not be frozen. Frozen solution will result in a 50-70% loss of activity.

Preparation Note
This product is offered as a catalase suspension in water containing 0.1% (w/v) thymol with activity of 40,000-60,000 units/mg protein. To remove the thymol preservative, the catalase crystals may be pelleted by centrifugation, the supernatant, discarded, the pellet resuspended in water, and then pelleted again. The enzyme is soluble in 50 mM potassium phosphate buffer at 1 mg/mL and pH 7.0.

Unit Definition
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.