Plant peroxidases

Table 2. Search and comparison of the regions of plant peroxidases homologous to the polysaccharide-binding site...

Possible function of polysaccharide-binding plant peroxidases... 

Passardi F. Penel C. Dunand C. (2004) Performing the paradoxial how plant peroxidase modify the cell wall / / Trends in Plant Sci. V.9. P. 534-540. 

Yoshida K, Kaothien P., Matsui T., Kawaoka A. (2003) Molecular biology and application of plant peroxidase genes / / Appl. Microbiol. Biotechnol. V. 60. P. 665 - 670. 

Takahama, U. Oniki, T. Enhancement of peroxidase-dependent oxidation of sinapyl alcohol hy esters of 4-coumaric and ferulic acid. In Plant Peroxidases, Biochemistry and Physiology Ohinger, C. Burner, U. Ebermann, R. Penel, C. Greppin, H., Eds. Universite de Geneve, Geneve Switzerland, 1996 pp. 118-123. 

The successful expression of recombinant plant peroxidases such as HRP C has been a major focus of research in a number of laboratories. Three synthetic HRP C genes based on the amino acid sequence determined by Welinder (36, 47) were synthesized independently in order to initiate this work (63-65). A number of different expression systems have been evaluated (64, 66-73), a summary of which is presented in Table I. Refolding of recombinant HRP C isolated from inclusion... 

The ability of HRP to degrade the plant hormone indole-3-acetic acid (lAA) in the absence of hydrogen peroxide was noted as early as 1955 (136). Plant peroxidases are now known to be of major importance in the metabolism of lAA (137) (note that they are often referred to as indole acetic acid oxidases in the older literature). The mechanism of lAA oxidation by HRP C is complex and has been studied experimentally in great detail by several groups (23, 137). Reaction products include indole-3-methanol, indole-3-aldehyde, and 3-methylene oxin-dole, which is probably a nonenzymatic conversion product of indole-3-methylhydroperoxide. The most important developments in this area have been reviewed (23). 

The mechanisms for the rednction of compounds I and II are less well nnderstood than the mechanism of compound I formation, although a number of suggestions have been presented in the literature (24). It is clear from site-directed mutagenesis studies that Arg38 and His42 are also important in the rednction steps, although their precise role has been difficnlt to define. A detailed mechanism for snbstrate oxidation by plant peroxidases has been proposed, based on data from the crystal... 

Fig. 6. Mechanisms for the reduction of compounds I and II of HRP C by ferulic acid, after Henriksen et al. 195). This scheme is based on new information from the 1.45 A resolution crystal structure of the ternary complex of ferulic acid and cyanide-ligated HRP C 195). The direction of proton transfer is indicated by the dotted arrows. The mechanism is discussed in Section IV,B,2, and the crystal structure data in Section IV,F,4. Note that a distal site water molecule makes an important hydrogen bond with the backbone carbonyl group of Prol39 (a residue conserved in all members of the plant peroxidase superfamily).

Gaspar, T Penel, C. Greppin, H. Plant Peroxidases 1980-1990. Progress and Prospects in Biochemistry and Physiology University of Geneva Geneva, 1992. 

International Working Group on Plant Peroxidases University of Geneva Geneva, http //www.unige.ch/LABPV/perox.html. 

Vind, J. DalbiSge, H. In Plant Peroxidases Biochemistry and Physiology Welinder,... 

KreU, H.-W. In Biochemical, Molecular and Physiological Aspects of Plant Peroxidases Lobarzewski, J., Greppin, H., Penel, C., Gaspar, T., Eds. University of Geneva Geneva, 1991 pp. 469-478. 

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