Peroxidases catalyze the decomposition of hydrogen peroxide coupled to the oxidation of a variety of organic and inorganic substrates. Produced by a broad variety of natural sources, most peroxidases use heme or vanadium as a cofactor at the redox active site, while some bacterial peroxidases function without a metal cofactor (1 ,2 ). Peroxidases catalyze a wide variety of oxidative reactions, some of which are used in industrial and biotechnological applications. An activity assay that can be used in a high-throughput fashion becomes important for the engineering of new and improved peroxidases.
