Peroxidases biological functions

Klebanoff SJ. Myeloperoxidase occurence and biological function. In Everse J, Everse KE, Grisham MB, eds. Peroxidases in Chemistry and Biology. Boca Raton, FL CRC Press 1991. 

Sources and Biological Functions of Peroxidases Mechanisms of Peroxidase Catalysis. ... 

Peroxidase Source Catalyzed Reaction Biological Functions... 

Crystal structures of manganese catalases (in the (111)2 oxidation state) from Lactobacillus plantarum,its azide-inhibited complex, " and from Thermus thermophilus have been determined. There are differences between the structures that may reflect distinct biological functions for the two enzymes, the L. plantarum enzyme functions only as a catalase, while the T. thermo-philus enzyme may function as a catalase/peroxidase. The active sites are conserved in the two enzymes and are shown schematically in Figure 32. Each subunit contains an Mu2 active site,... 

The only biological function which has been repeatedly confirmed is the role of peroxidases in lignin monomer polymerization (1). But even in this case, the role of the various isozymes is not yet clear, although anionic, cell wall bound peroxidases generally seem to be involved in lignification... 

The H202 formed may be reduced by catalase, peroxidase or suitable reducing agents. SOD has been identified in many animal and bacterial cells its biological function is to protect tissue against oxygen free radicals in anaerobic systems (reviewed by Farkye, 1992). 

Catalases are structural relatives of the peroxidases in that they contain a heme tetramer at the active site [241]. Their biological function is to control the cellular concentration of hydrogen peroxide by the following disproportionation reaction ... 

Oxidative dehydrogenation is a primary biological function of peroxidases. Compound... 

The properties and biological function of LPO have recently been reviewed. This secretory peroxidase is isolated from cow s milk. Crystalline LPO from bovine milk was obtained in 1943 and shown to be green colored like MPO. Its isolation and purification was simplified by precipitation of casein by rennet. The enzyme with a single polypeptide chain has been known to exist as several isoenzyme forms. The Soret maxima of LPO of 412 nm with molar absorptivity of 112 mM cm is typical of most peroxidases. It recently has been demonstrated that the heme in LPO is attached to the protein by ester bonds between the heme 1- and 5-methyl groups, and Glu375 and Asp275, respectively. ... 

Poulos, T. M. Fenna, R. E. Peroxidases Structure, Function and Engineering. In Metal Ions in Biological Systems Sigel, H. Sigel, A., Eds. Marcel Dekker New York, 1994 Vol. 30, pp 25-75. 

Cytochrome c is a small haem protein with a molecular mass of around 12 kDa the precise value depends on the origin of the protein. Its biological function is to accept an electron at Complex III of the respiratory chain and deliver it to Complex IV, the terminal oxidase, normally cytochrome c oxidase. In yeast and some bacteria, cytochrome c peroxidase (CcP, EC 1.11.1.5) may act as an alternative electron acceptor. Cytochrome c has around 104 amino acid residues, 27 of which are known to be invariant between 50 different organisms. The protein is about 3.4 nm in diameter, and crystal structures on a number of examples from... 

Table 2 Common peroxidases and their biological functions...

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