Peroksüdaases

Peroksüdaases are a class of enzymes that catalyze oxidation reactions using hydrogen peroxide as a co-substrate. They belong to the oxidoreductase family, specifically the heme-containing peroxidases. These enzymes are widespread in nature and play crucial roles in various biological processes across different organisms.

In humans, peroxidases are involved in immune defense mechanisms, such as the breakdown of harmful pathogens by neutrophils. They are also implicated in processes like thyroid hormone synthesis, where the enzyme thyroperoxidase catalyzes the iodination of tyrosine residues on thyroglobulin. Plant peroxidases are important for defense against pathogens, cell wall metabolism, and lignin biosynthesis. Microorganisms also utilize peroxidases for detoxification of reactive oxygen species and for metabolic pathways.

The catalytic mechanism of peroxidases typically involves the activation of hydrogen peroxide to form a high-valent iron-oxo intermediate (Compound I). This intermediate then oxidizes a substrate, regenerating the enzyme in its resting state. The specific substrates oxidized by peroxidases are diverse and depend on the enzyme's origin and function, ranging from small molecules like halides and phenols to larger biomolecules. The study of peroxidases is important for understanding cellular redox homeostasis, disease mechanisms, and for developing biotechnological applications, such as biosensors and biocatalysts.