Coprinus peroxidase

Hoft reported about the kinetic resolution of THPO (16b) by acylation catalyzed by different lipases (equation 12) °. Using lipases from Pseudomonas fluorescens, only low ee values were obtained even at high conversions of the hydroperoxide (best result after 96 hours with lipase PS conversion of 83% and ee of 37%). Better results were achieved by the same authors using pancreatin as a catalyst. With this lipase an ee of 96% could be obtained but only at high conversions (85%), so that the enantiomerically enriched (5 )-16b was isolated in poor yields (<20%). Unfortunately, this procedure was limited to secondary hydroperoxides. With tertiary 1-methyl-1-phenylpropyl hydroperoxide (17a) or 1-cyclohexyl-1-phenylethyl hydroperoxide (17b) no reaction was observed. The kinetic resolution of racemic hydroperoxides can also be achieved by chloroperoxidase (CPO) or Coprinus peroxidase (CiP) catalyzed enantioselective sulfoxidation of prochiral sulfides 22 with a racemic mixmre of chiral hydroperoxides. In 1992, Wong and coworkers and later Hoft and coworkers in 1995 ° investigated the CPO-catalyzed sulfoxidation with several chiral racemic hydroperoxides while the CiP-catalyzed kinetic resolution of phenylethyl hydroperoxide 16a was reported by Adam and coworkers (equation 13). The results are summarized in Table 4. 

The same authors also investigated the kinetic resolution of racemic hydroperoxides with Coprinus peroxidase (CiP), isolated from the basidiomycete Coprinus cinereus... 

As enantiomericaUy pure sulfoxides are excellent chiral auxUiaries for asymmetric synthesis, different approaches for biocatalytic asymmetric oxidations at the S-atom have been explored [30, 31]. Asymmetric peroxidaseorganic sulfides to sulfoxides in organic solvents opens up attractive opportunities by increased substrate solubility and diminished side reactions [32]. Plant peroxidases located in the cell wall are capable of oxidizing a broad range of structurally different substrates to products with antioxidant, antibacterial, antifungal, antiviral, and antitumor activities [33]. Hydroperoxides and their alcohols have been obtained in excellent e.e. in the biocatalytic kinetic resolution of secondary hydroperoxides with horseradish and Coprinus peroxidase [34]. 

APX, ascorbate peroxidase PJiP, Arthromyces ramosus peroxidase BPl, barley grain peroxidase CCP, C3dochrome c peroxidase CIP, Coprinus cinereus peroxidase EXAFS, extended X-ray absorption fine structure HRP, horseradish peroxidase HRP Z (where Z = A1-A3, B1-B3, Cl, C2, D, E1-E6, or N), a specific isoenzyme of horseradish peroxidase HS, high-spin lAA, indole-3-acetic acid LIP, hgnin peroxidase LS, low-spin PNP, the major cationic isoenzyme of peanut peroxidase WT, wild-type 5-c, five-coordinate 6-c, six-coordinate. 

Chemical modification of surface residues of HRP is one method which may offer some improvement in thermal or long-term stability of the enzyme. The -amino groups of the six surface Lys residues can be modified by reaction with carboxylic anhydrides and picryl sulfonic acid (296). In this example the number of sites modified was found to be more significant than the chemical nature of the modification, at least as a criterion for improved stability. Other methods explored include the use of bifunctional crosslinking reagents to couple surface sites on the enzyme (297). Future developments are likely to be concerned with the selection of site-directed mutants of HRP C that show enhanced thermal stability. Dramatic increases in thermal stability of up to 190-fold have been reported recently for mutants of Coprinus cinereus peroxidase (CIP) generated using a directed evolution approach (298). 

An alternative method for coupling enzymes is to employ a mixed enzyme bioreactor Pezzotti and Therisod [60] reported a bienzymatic system in which alcohol oxidase and peroxidase were coupled to effect the enantioselective oxidation of the sulfide thioanisole (Scheme 3.4). Here, the peroxidase from Coprinus dnereus was mixed with a crude extract of Pichia pastoriz alcohol oxidase and the two enzyme mixture was successfully used to convert gram quantities of thioanisole enantiose-lectively to S-methyl-phenyl-sulfoxide with an enantiomeric excess of 75%. 

Several fungal peroxidases have also been investigated. A fungal peroxidase from Coprinus macrorhizus was used to treat aqueous phenols... 

Al-Kassim L, Taylor KE, Nicell JA, Bewtra JK, Biswas N. Enzymatic removal of selected aromatic contaminants from wastewater by a fungal peroxidase from Coprinus macrorhizus in batch reactors. J Chem Technol Biotechnol 1994 61 179-182. 

Ciaccio C, Rosati A, De Sanctis G et al (2003) Relationships of ligand binding, redox properties, and protonation in Coprinus cinereus peroxidase. J Biol Chem 278 18730-18737... 

Kim YH, Won K, Kwon JM et al (2005) Synthesis of polycardanol from a renewable resource using a fungal peroxidase from Coprinus cinereus. J Mol Catal B Enzym 34 33-38... 

An enzymatic method to remove dioxins from fishmeal has been investigated using Coprinus cinereus peroxidase, cloned and expressed in Aspergillus sp. and did not result in a major degradation of dioxins with only 10-15% reduction achieved [120]. 

Coprinus cimreus peroxidase Phenolic waste stream [2]... 

The plug flow reactor has been mainly utilized for the removal of phenol in waste streams by HRP [76, 83] and Coprinus cinereus peroxidase [2]. According to Buchanan et al. [83], who modeled the kinetics of the HRP-aromatic substrate system and applied to PFR and CSTR, plug-flow configuration is recommended when working with low HRT, since considerably less enzyme would be required for equal phenol removal. However, for long HRTs, a multiple-stage CSTR would be more efficient than a PFR, due to the lower rate of enzyme inactivation. 

Masuda M, Sakurai A, Sakakibara M (2001) Effect of enzyme impurities on phenol removal by the method of polymerization and precipitation catalyzed by Coprinus cinereus peroxidase. Appl Microb Biotechnol 57 494 -99... 

Chang HC, Holland RD, Bumpus JA et al (1999) Inactivation of Coprinus cinereus peroxidase by 4-chloroaniline during turnover comparison with horseradish peroxidase and bovine lactoperoxidase. Chem Biol Interact 123 197-217... 

CPO Chloroperoxidase CPO nonheme chloroperoxidase LiP Lignin peroxidase LiPH2 Lignin peroxidase H2 isozyme MnP Manganese peroxidase CiP Coprinus cinereus peroxidase ARP Arthromyces ramosus peroxidase... 

Of the plant peroxidases, which are found in abundance in the peroxisomes, the 40-kDa monomeric horseradish peroxidase has been studied the most. " It occurs in over 30 isoforms and has an extracellular role in generating free radical intermediates for polymerization and crosslinking of plant cell wall components. Secreted fungal peroxidases, e.g., such as those from Coprinus ° and Arthromyces form a second class of peroxidases with related struc-tues. A third class is represented by ascorbate peroxidase from the cytosol of the pea " and by the small 34-kDa cytochrome c peroxidase from yeast mitochondria (Fig. 16-11). The latter has a strong preference for reduced cytochrome c as a substrate (Eq. 16-9). " ... 

Horseradish peroxidase (HPO) has been reported to be threefold more stable at 80°C in 5-10% [bmim+][BF ] as compared to phosphate buffer [28], Okrasa et al. [29] reported the asymmetric oxidation of phenyl methyl- and 2-naphthyl methyl sulphides to sulphoxides catalysed by peroxidase from Coprinus cinereus in [bmim ] [PP6-] with 10% water [29], Although the enantioselectivity (63-92% ee) and yields (<32%) were similar to those in water, the reaction workup was easier because ionic liquids and the extraction solvent did not form emulsions. 

Similarly, Coprinus cinereus (CcP) peroxidase-catalyzed conversion of thioani-sole to sulfoxides has been studied in [BMIM] [PFJ in a biphasic reaction medium... 

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