Uses
Pulmonary artery endothelial cells treated with PEG-catalase showed effective inhibition of 20- HETE (hydroxyeicosatetraenoic acid)-induced increase in fluorescence. However, the experiment excludes potential nonspecific fluorescence of DCF (dichlorofluorescein). This experiment studied the effect of 20-HETE on superoxide production and NADPH oxidase activation.
Biochem/physiol Actions
Catalase from bovine liver catalyzes the decomposition of H2O2 into water and oxygen. It is a tetramer consisting of four equal subunits with a molecular weight of 60 kDa each. Each subunit contains iron bound to a protoheme IX group. The enzyme also strongly binds NADP, which is in close proximity to the heme group. Catalase activity is constant over the pH range of 4.0-8.5. The pI is found to be 5.4. The enzyme activity is inhibited by 3-amino-1-H-1,2,4 triazole, cyanide, azide, hydroxylamine, cyanogen bromide, 2-mercaptoethanol, dithiothreitol, dianisidine, and nitrate. Incubation of catalase with ascorbate or ascorbate/Cu2+ results in degradation of the catalase molecule. It does not require any activators.
