Ligninase

Haemmerli D, MSA Leisola, D Sanglard, A Fiechter (1986) Oxidation of benzo[a]pyrene by extracellular ligninases of Phanerochaete chrysosporium. J Biol Chem 261 6900-6903. 

Hammel KE, B Kalyanaraman, TK Kirk (1986) Oxidation of polycyclic aromatic hydrocarbons and dibenzo(p)dioxins by Phanerochaete chrysosporium ligninase. J Biol Chem 261 16948-16952. 

Purified ligninase H8 produced by P. chrysosporium in stationary cultures oxidized pyrene to pyrene-1,6- and pyrene-l,8-quinones in high yield, and experiments with showed that both quinone oxygen atoms originated in water (Figure 8.25). It was suggested that initial one-electron abstraction produced cation radicals at the 1 and 6 or 8-positions (Hammel et al. 1986), whereas in... 

Wang, P., Woodward, C.A., and Kaufman, E.N., Polyethylene glycol)-modified ligninase enhances pentachlorophenol biodegradation in water-solvent mixtures, Biotechnol. Bioeng., 64, 290-297, 1999. 

Kersten PJ, Tien M, Kalyanaraman B, Kirk TK (1985) The ligninase from Phanerochaete chrysosporium generates cation radicals from methoxybenzenes. J Biol Chem 260 2609-2612... 

However, we have observed that values obtained with crude extracts were only qualitative. Often, they did not accurately estimate the quantities of the individual enzymes present. Inhibitors were typically present that caused the underestimation of certain enzymes ie.g., ligninases Table II) and that could potentially mask less dominant enzymes. Also, certain polysaccharidases e.g., hemicellulases) were often overestimated due to the action of non-specific or synergistic enzymes e.g., other hemicellulases or cellulases) (9,14), This artifact resulted in low apparent recovery of a given activity and only moderate increases in specific activity upon purification of the major corresponding enzyme present, in spite of the fact that SDS polyacrylamide gels indicated good recovery and substantial removal of contaminants (14),... 

Table II. Purification Table for the Manganese Peroxidase (Ligninase) Isolated from Lentinula edodes Cultures Grown on a Commercial Wood Medium ...

Figure 4. Enzyme activities in analytical QM anion exchange column fractions detected with substrates selected for laccases, peroxidases (including ligninases), acid phosphatases, and acid proteinases. Major peaks are numbered. (Reproduced with permission from ref. 9. Copyright 1990 Society of Fermentation Technology, Japan.)...

Figure 5. Optical absorbance at 280nm and 409nm (denoting heme-iron containing ligninases) for fractions from the preparative DEAE anion exchange column and salt gradient used to fractionate the enzymes in a crude culture extract. (Reproduced widi permission from ref. 15. Copyright 1990 Springer-Verlag.)...

The value and potential usefulness of a new enzyme depends on its properties and the extent to which it has been characterized. The initial characterization of an enzyme often involves the determination of its pH optimum, stability, gross physical properties, and substrates. The enzymes of L. edodes, typically show pH optima between 3.5 and 5.0, maximal activity at 50 to 60"C, little activity loss until over 70"C, and high relative specific activities (9,14). Below we will highlight some of the other characteristics determined for the major ligninase, p-(l,4)-D-xylanase, and a-(l,3)-L-arabinosidase purified from wood-grown cultures of L. edodes. 

This heme-dependent enzyme [EC 1.11.1.14], also known as diarylpropane peroxidase, diarylpropane oxygenase, and ligninase I, catalyzes the reaction of 1,2-bis(3,4-dimethoxyphenyl)propane-l,3-diol with hydrogen peroxide to produce veratraldehyde, l-(3,4-dimeth-ylphenyl)ethane-l,2-diol, and four water molecules. The enzyme brings about the oxidative cleavage of C—C bonds in a number of model compounds and also oxidizes benzyl alcohols to aldehydes or ketones. 

As can also be seen, veratrylglycerol undergoes Ca-C/3 bond cleavage, yielding veratraldehyde and glycolaldehyde in the presence of ligninase ... 

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