Fish Catalase, CAT ELI

Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen.

It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS).

Likewise, catalase has one of the highest turnover numbers of all enzymes; one catalase molecule can convert millions of hydrogen peroxide molecules to water and oxygen each second. Catalase is a tetramer of four polypeptide chains, each over 500 amino acids long.

It contains four iron-containing heme groups that allow the enzyme to react with the hydrogen peroxide.

The optimum pH for human catalase is approximately 7, and has a fairly broad maximum: the rate of reaction does not change appreciably between pH 6.8 and 7.5.

The pH optimum for other catalases varies between 4 and 11 depending on the species.

The optimum temperature also varies by species.