Peroxidase Biochemistry and Redox Signaling

Peroxidases are enzymes capable of reducing hydrogen peroxide and other hydroperoxides to water. Several substrates are oxidized during this process. Peroxidases are distinguished into heme and non-heme peroxidases, according to the chemistry of the active site interacting with peroxide. The former contain a heme catalytic center; the latter have a selenol or reactive thiol at their active site. Specific enzymatic features and biochemical attributes of peroxidases are described here. In particular, in addition to their well-known peroxide-scavenging properties, peroxidases also have oxidizing physiological functions. As hydrogen peroxide is emerging as an important regulatory molecule in redox signaling, the fundamental role of peroxidases in this subject is also described.