Peroxidases (
EC number 1.11.1.x) are a large family of
enzymes. A majority of peroxidase protein sequences can be found in the
PeroxiBase database. Peroxidases typically catalyze a reaction of the form
For many of these enzymes the optimal substrate is hydrogen peroxide, but others are more active with organic hydroperoxides such as lipid peroxides. Peroxidases can contain a heme cofactor in their active sites, or redox-active cysteine or selenocysteine residues.
The nature of the electron donor is very dependent on the structure of the enzyme.
While the exact mechanisms have yet to be elucidated, peroxidases are known to play a part in increasing a plant's defenses against pathogens.[1] Peroxidases are sometimes used as histological marker. Cytochrome c peroxidase is used as a soluble, easily purified model for cytochrome c oxidase.
