General description

Horseradish peroxidase is isolated from horseradish roots (Amoracia rusticana) and belongs to the ferroprotoporphyrin group of peroxidases. HRP is a single chain polypeptide containing four disulfide bridges. It is a glycoprotein containing 18% carbohydrate. The carbohydrate composition consists of galactose, arabinose, xylose, fucose, mannose, mannosamine, and galactosamine depending upon the specific isozyme. Its molecular weight (~44 kDa) includes the polypeptide chain (33,890 Daltons), hemin plus Ca²⁺ (~700 Daltons), and carbohydrate (~9,400 Daltons). At least seven isozymes of HRP exist. The isoelectric point for horseradish peroxidase isozymes ranges from 3.0 - 9.0.

Application

Horseradish peroxidase (HRP) is isolated from horseradish roots (Amoracia rusticana). It is used in biochemistry applications such as western blots, ELISA and Immunohistochemistry. Horseradish peroxidase is used to amplify a weak signal and increase detectability of a target molecule, such as a protein. Product P6782 is type VI-A and premium quailty. It is essentially a salt-free, lyophilized powder. It is used to quantify cholesterol and cholesterol esters and to study in vitro lipid deposition on hydrogel and silicone hydrogel contact lenses

The enzyme from Sigma has been used in the development of rapid and sensitive galactose oxidase-peroxidase biosensor for galactose detection with prolonged stability. It has been used as a component of a media (MRS agar) plate containing 3,3′,5,5′-tetramethylbenzidine (TMB) for the growth of Lactobacillus sp. TMB acts as a chromogenic substrate of peroxidase. Peroxidase generates O₂ from H₂O₂ produced by the lactobacilli, and the TMB stains the colonies blue in the presence of O₂. Thus, after 48 hours of incubation under 5% CO₂ in air, the colonies that produce H₂O₂ on MRS agar appear dark blue. H₂O₂ nonproducers are colorless. It has been used to study the stabilization effect of polyvinyl alcohol on horseradish peroxidase.It is also used for the determination of glucose and peroxidesin solution.