Enzyme lignin peroxidase

Transmission electron microscopy of immunogold labelled sections has shown that the extracellular lignin-degrading enzymes lignin-peroxidase and laccase were localized within the cell wall and mucilage of the hyphae of C. versicolor. Laccase was present in the cell wall layer whereas lignin-... 

Unfortunately, not all PAHs are substrates for peroxidases. A correlation has been found between the ionization potential (IP) of PAHs and the specific activity of manganese peroxidase, lignin peroxidase, hemoglobin, and chloroperoxidase. A threshold value of IP was found for each enzyme. Lignin peroxidase oxidizes PAHs with IP = 7.55 eV [87], while manganese peroxidase oxidizes PAHs with IP... 

Lignin peroxidase Lignin modifying enzyme Manganese peroxidase Polyacrylamide gel electrophoresis... 

Measuring Lignin peroxidase, Laccase and MnP activities in decolorization medium is a method to determine the enzyme responsible for decolorization [15, 17, 25],... 

Lignin peroxidases enzymes In-process control, semipreparative purification, comparison with conventional columns Anion Exchange disks [80]... 

Peroxidases (E.C. 1.11.1.7) are ubiquitously found in plants, microorganisms and animals. They are either named after their sources, for example, horseradish peroxidase and lacto- or myeloperoxidase, or akin to their substrates, such as cytochrome c, chloro- or lignin peroxidases. Most of the peroxidases studied so far are heme enzymes with ferric protoporphyrin IX (protoheme) as the prosthetic group (Fig. 1). However, the active centers of some peroxidases also contain selenium (glutathione peroxidase) [7], vanadium (bromoperoxidase)... 

Effect of pH on Lignin Peroxidase Catalysis. The oxidation of organic substrates by lignin peroxidase (Vmax) has a pH optimum equal to or possibly below 2. Detailed studies have been performed on the pH dependency of many of the individual reactions involved in catalysis. The effect of pH on the reaction rates between the isolated ferric enzyme, compounds I or II and their respective substrates has been studied. Rapid kinetic data indicate that compound I formation from ferric enzyme and H2O2 is not pH dependent from pH 2.5-7.5 (75,16). Similar results are obtained with Mn-dependent peroxidase (14). This is in contrast to other peroxidases where the pKa values for the reaction of ferric enzyme with H2O2 are usudly in the range of 3 to 6 (72). 

Since compound II has a Soret peak at 420 nm and the oxycomplex 416 nm, the equilibrated solution of compound II, H2O2, and compound III should exhibit an intermediate absorption peak. The existence of such an equilibrium has been established with HRP (22) and was also observed with lignin peroxidase (Cai, D., and Tien, M., unpublished results 23). Wariishi and Gold (25) recently proposed the existence of a new enzyme intermediate when compound in is formed in the presence of H2O2. They referred to this intermediate as compound III and suggested it to be a complex between compound III and H2O2. The existence of such an intermediate was based primarily on the Soret spectral properties where a 419 nm maximum was observed. In contrast, we see no evidence for existence of such a complex. The observed 419 nm absorbance maximun can be best explained by the existence of both compounds II and III in solution. 

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