Catalase is a common enzyme found in almost all living organisms that use oxygen. Catalyzes the decomposition of hydrogen peroxide into water and oxygen. Catalase is a very important enzyme in protecting the cell from oxidative damage caused by reactive oxygen species (ROS).
Catalase measurement in the context of Oxidative Stress tests can help identify the underlying causes for many chronic diseases and clinical disorders, so that appropriate individualized therapeutic interventions can be designed.
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Catalase is one of the antioxidant enzymes, such as superoxide dismutase (SOD) and glutathione superoxidase, and is produced normally in all cells of the body. Catalase can also catalyze oxidation through hydrogen peroxide, potentially harmful toxins to the body, including alcohol, phenol, and formaldehyde.
All aerobic organisms need oxygen to live, but when cells use oxygen, free radicals are produced that damage cell membranes, proteins, and DNA. Free radicals are chemically unstable atoms or molecules that create other unstable also, atoms and molecules in the body, a process that causes extensive damage to cells and tissues and can lead to damage to the immune system, infections and inflammation, cardiovascular diseases, and neurodegenerative diseases, among others. Free radicals are also considered to be a key element in the aging process.
Catalase works closely with superoxide dismutase to prevent free radical damage to the body. Superoxide dismutase converts the dangerous peroxide radical to hydrogen superoxide, which then catalase catalyzes the conversion to harmless water and oxygen. Catalase is one of the most effective enzymes found in cells. Each one catalase molecule can convert millions of molecules of hydrogen superoxide to water and oxygen, every second.
Hydrogen peroxide is a natural but destructive byproduct of the metabolism of all oxygen-dependent organisms. It is produced in the human body when fatty acids are converted into energy and when white blood cells attack and kill microbes. Catalase, which is found in the peroxisomes of the cell, prevents this normally produced hydrogen peroxide from damaging the cell during these processes. It also helps prevent the conversion of hydrogen peroxide into hydroxyl radicals, potentially dangerous molecules that can react with DNA and cause mutations.
It is believed that one of the main causes of cell aging is DNA damage caused by free radicals and oxidizing agents such as hydrogen peroxide and that increasing levels of the body's natural defense antioxidant systems - both enzymatic (catalase, peroxide dismutase, etc.) and non-enzymatic ones (vitamins, glutathione, etc.) - can improve health levels. It is possible that aging is ultimately the result of exposure to free radicals and not the passage of time.
Low levels of catalase may play a role in the process of graying hair in humans. Hydrogen peroxide normally produced by the body is broken down by catalase. If catalase levels are reduced, hydrogen peroxide cannot be broken down effectively. Hydrogen peroxide interferes with the production of melanin, the pigment that gives hair its color. Mice that are genetically engineered to lack catalase are initially phenotypically normal. However, catalase deficiency in experimental animals may increase the likelihood of developing obesity, fatty liver disease, and type 2 diabetes.
Structurally, catalase is a tetramer of four polypeptide chains. It contains four heme groups that contain iron and that allow the enzyme to react with hydrogen peroxide. Any metal ion (such as copper cations) can act as a non-competitive catalase inhibitor. The optimum pH for human catalase is about 7.
