Purification of Natural Plant Peroxidases and their Physiological Roles

The plant peroxidase superfamily comprises heme-containing glycoproteins that differ in their structure and catalytic properties. POX has been isolated and characterized from a large number of plant sources like fruits, leaves, tubers and grains, and the major source of commercially available peroxidase is horseradish roots. However, availability of POX with higher stability and different specificity would improve immunoenzymatic analytical kits and promote the development of new analytical methods and potential industrial processes. Therefore, extensive investigations of several peroxidases of different origins have been reported. The diversity of reactions catalyzed by plant peroxidases (POX) accounts for the implication of several isoenzymes in a broad range of physiological processes including indole3-acetic acid metabolism, pathogen resistance, response to oxidative and chemical stresses involving reactive oxygen species, and lignin and suberin biosynthesis. In addition, the recent description of the hydroxylic cycle which leads to the formation of various radical species, opens a new range of implications for these enzymes. A major limitation for the widespread use of POX is the current high cost of production of the enzyme. A cost-effective purification technology and alternative sources with high peroxidase activity can help bring down the cost of this enzyme production. _____________________________________________________________________________________________________________