Catalase from human erythrocytes

General description

Research area: Cell Signaling

Human catalase is a member of the monofunctional heme-containing catalases. It is an intracellular enzyme located at higher concentrations in the liver, erythrocytes, and kidney. Catalase is a homo-tetrameric protein and comprises amino acid residues, one heme group that is iron III protoporphyrin IX, and a nicotinamide adenine dinucleotide phosphate (NADPH) molecule. It is a ubiquitous enzyme found in most aerobic organisms. The catalase (CAT) gene is located on the human chromosome at 11p13.

Application

Catalase from human erythrocytes has been used:

• to prevent reoxidation of reduced cytochrome c by H2O2 while measuring the production of superoxide with cytochrome C.
• as a component of the imaging buffer for stochastic optical reconstruction microscopy (STORM) imaging of human skin fibroblasts
• as a component of the gloxy mix for single-molecule imaging

Biochem/physiol Actions

Deficiency of catalase and oxidative stress are associated with vitiligo, hypertension, Alzheimer′s disease, diabetes mellitus, and acatalasemia. Catalase shows a dichotomous role in cancer as its expression is at a higher level in chronic lymphocytic leukemia, glioma, melanoma, and gastric cancer and lower levels of expression are seen in acute myeloid leukemia, pancreatic, lung, prostate, and skin (non-melanoma) cancers.

Catalase activates the decomposition of hydrogen peroxide, a reactive oxygen species, into water and oxygen. It functions as a natural antioxidant, protecting cells against oxidative damage to proteins, lipids and nucleic acids. Catalase has also been used to study the role reactive oxygen species play in gene expression and apoptosis.

Unit Definition

One unit will decompose 1.0 μmole of H₂O₂ per min at pH 7.0 at 25 °C, while the H₂O₂ conc. falls from 10.3 to 9.2 mM, measured by the rate of decrease of A₂₄₀.

Physical form

Solution in 50 mM Tris, pH 8.0

Analysis Note

Protein determined by biuret