What is the Catalase enzyme

What is the Catalase enzyme

What are enzymes

Enzymes are vital to our survival. Such proteins, produced by our cells, allow our body to process chemicals, acting as a catalyst. A catalyst gets reactions started and makes them happen quicker, by increasing a reaction rate that might not happen at all otherwise, or may take too long to sustain life. A catalyst does not participate in the reaction itself though so how does it work? Each chemical reaction requires a minimum amount of energy for this to happen. This energy is called energetic activation. The lower a reaction’s triggers energy, the quicker it takes place. If the activation energy is too small, then there is no reaction.

Enzymes have the ability to reduce a chemical reaction’s activation energy by interacting with its reactants (the chemicals that do the reaction). Each enzyme has an active site at which the reaction occurs. These sites are as special pockets capable of binding a chemical molecule. The compounds or molecules with which the enzyme reacts are named their substrates. The enzyme pocket has a specific form, such that only one particular substratum can bind to it, just as only one key fits into a particular lock. The chemical reaction occurs once the molecule is bound to the enzyme. The reaction products are then released from the bag, and the enzyme is ready to start to  all over again with another substrate molecule.

The catalase enzyme

Have you ever asked how they digest all the food you eaten? It’s not just the acid that breaks down the food in the stomach many little molecules in your body, called enzymes, help with that too. Enzymes are special protein types which accelerate chemical reactions, such as the digestion of food in your stomach .There are literally thousands of different enzymes in your body working around the clock to keep you healthy and active.  Catalase is one of these enzymes that helps protect your body from harm.

The catalase enzyme and its importance

Catalase is a very common enzyme, present in almost all oxygen exposed organisms. Within living cells, catalase is meant to protect them from oxidative damage, which may occur when cells or other molecules come into contact with oxidative compounds in the body. This damage is a natural consequence of reactions occurring within your cells. The reactions that contain by products such as hydrogen peroxide, which can be toxic to the body, as well as how excessive smoke may be a by product of a nice bonfire that makes you cough or sting your eyes. To prevent such damage, the catalase enzyme helps by breaking up hydrogen peroxide (H2O2) into harmless water and oxygen to get rid of these compounds.

How does catalase enzyme work?

The body has a defense mechanism against oxidative stress in which both enzymatic and nonenzymatic molecules are the two prime components. This antioxidant defense system consists of some enzymes, some proteins, and a few low molecular weight molecules. The antioxidant enzymes can catalytically remove the reactive species. For example, superoxide dismutase dismutates superoxide into hydrogen peroxide which is in turn degraded by catalase or by glutathione peroxidase.

CAT is a tetrameric enzyme, which promotes the reduction of H2O2 to H2O and O2. Mammalian CAT is exclusively located in the peroxisomes and utilizes H2O2 generated during fatty acid oxidation (FAO) in these organelles. Treatment of cells with H2O2 activates the Abelson (Abl) family of nonreceptor tyrosine kinases, c-Abl and Arg, that phosphorylate CAT leading to an increase in its activity. However, CAT-deficient mice display no marked abnormalities, leaving the question of the precise role of CAT in OS response open to debate.

Catalase activity will eliminate hydrogen peroxide which will in turn reduce fluorescein (less DCF substrate oxidation). It is reckoned as follows:

This process is then calibrated against total protein content (mg / mL) or tissue weight (g / mL) to result in the loss of protein hydrogen peroxide / min / mg or tissue weight g.

Fluorescein Formed/15min) at0min]−[(Fluorescein formed/15min)at20min]=HPP / min / mL]

The interaction of catalase with other antioxidants and proteins can be predicted by the STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) analysis.

STRING is a biological database used to study protein protein interaction.

The STRING network analysis of catalase’s interaction with other proteins has been categorized into two distinct modules. Module 1 contains four proteins which are basically involved in the pathways of peroxisomes including CAT and three proteins of module 2 such as SOD1), SOD2 (superoxide dismutase 2), and PRDX5 (peroxiredoxin 5). In module 1, ACOX1 (peroxisomal acyl coenzyme A oxidase), HSD17B4 (peroxisomal multifunctional enzyme), and HAO1 (hydroxy acid oxidase 1) are involved in the fatty acid oxidation pathway in the peroxisome while the protein DAO (D amino acid oxidase) is involved in the amino acid metabolism pathway in the peroxisome.  All the components of module 1 are involved in different metabolic pathways. The proteins in module 2 are mainly involved in responses against oxidative stress. All the proteins have antioxidant activity except AKT1 (RAC-alpha serine-threonine protein kinase). AKT1 is a serine-threonine protein kinase which is involved in cell survival, metabolism, growth, and angiogenesis. All the proteins of both modules 1 and 2 including CAT have catalytic activity and are located in the lumen of intracellular organelles.

To conclude

A catalase is one of the most important antioxidant enzymes. It is present in almost all aerobic organisms. Catalase breaks down two hydrogen peroxide molecules into one molecule of oxygen and two molecules of water in a two step reaction.

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