@misc{GroebeUllrichPecynaetal., author = {Gr{\"o}be, Glenn and Ullrich, Ren{\´e} and Pecyna, Marek J. and Kapturska, Danuta and Friedrich, Stephanie and Hofrichter, Martin and Scheibner, Katrin}, title = {High-yield production of aromatic peroxygenase by the agaric fungus Marasmius rotula}, series = {AMB Express}, journal = {AMB Express}, issn = {2191-0855}, abstract = {An extracellular peroxygenase from Marasmius rotula was produced in liquid culture, chromatographically purified and partially characterized. This is the third aromatic peroxygenase (APO) that has been characterized in detail and the first one that can be produced in high yields. The highest enzyme levels of about 41,000 U l-1 (corresponding to appr. 445 mg l-1 APO protein) exceeded the hitherto reported levels more than 40-fold and were detected in carbon- and nitrogen-rich complex media. The enzyme was purified by FPLC to apparent homogeneity (SDS-PAGE) with a molecular mass of 32 kDa (27 kDa after deglycosylation) and isoelectric points between 4.97 and 5.27. The UV-visible spectrum of the native enzyme showed a characteristic maximum (Soret band) at 418 nm that shifted after reduction with sodium dithionite and flushing with carbon monoxide to 443 nm. The pH optimum of the M. rotula enzyme was found to vary between pH 5 and 6 for most reactions studied. The apparent Km-values for 2,6-dimethoxyphenol, benzyl alcohol, veratryl alcohol, naphthalene and H2O2 were 0.133, 0.118, 0.279, 0.791 and 3.14 mM, respectively. M. rotula APO was found to be highly stable in a pH range from 5 to 10 as well as in the presence of organic solvents (50\% vol/vol) such as methanol, acetonitrile and N,N-dimethylformamide. Unlike other APOs, the peroxygenase of M. rotula showed neither brominating nor chlorinating activities.}, language = {en} } @misc{PeterKarichUllrichetal., author = {Peter, Sebastian and Karich, Alexander and Ullrich, Ren{\´e} and Gr{\"o}be, Glenn and Scheibner, Katrin and Hofrichter, Martin}, title = {Enzymatic one-pot conversion of cyclohexane into cyclohexanone: Comparison of four fungal peroxygenases}, series = {Journal of Molecular Catalysis : B, Enzymatic}, journal = {Journal of Molecular Catalysis : B, Enzymatic}, number = {103}, doi = {10.1016/j.molcatb.2013.09.016}, pages = {47 -- 51}, abstract = {Unspecific peroxygenases (UPO; EC 1.11.2.1) represent a group of secreted heme-thiolate proteins that are capable of catalyzing the mono-oxygenation of diverse organic compounds, using only H2O2 as a co-substrate. Here we show that the four peroxygenases AaeUPO, MroUPO, rCciUPO and rNOVO catalyze the stepwise hydroxylation of cyclohexane to cyclohexanol and cyclohexanone. The catalytic efficiencies (kcat/Km) for the initial hydroxylation were in the same order of magnitude for all four peroxygenases (∼104 M-1 s-1), whereas they differed in the second step. The conversion of cyclohexanol by AaeUPO and rCciUPO was 1-2 orders of magnitude less efficient (∼102 M-1 s-1) than by MroUPO and rNOVO (∼104 M-1 s-1). The highest conversion rate in terms of H2O2 utilization was accomplished by MroUPO under repeated addition of the peroxide (87\% in relation to the total products formed). Using the latter UPO, we successfully established a micro-mixing reaction device (SIMM-V2) for the oxidation of cyclohexane. As cyclohexanone is a chemical of high relevance, for example, as starting material for polymer syntheses or as organic solvent, new enzymatic production pathways for this compound are of interest to complement existing chemical and biotechnological approaches. Stable and versatile peroxygenases, as those presented here, may form a promising biocatalytic platform for the development of such enzyme-based processes.}, language = {en} } @misc{PiontekStrittmatterUllrichetal., author = {Piontek, Klaus and Strittmatter, Eric and Ullrich, Ren{\´e} and Gr{\"o}be, Glenn and Pecyna, Marek J. and Kluge, Martin and Scheibner, Katrin and Hofrichter, Martin and Plattner, Dietmar A.}, title = {Structural basis of substrate conversion in a new aromatic peroxygenase: cytochrome P450 functionality with benefits}, series = {The Journal of Biological Chemistry}, journal = {The Journal of Biological Chemistry}, number = {288}, issn = {1083-351X}, doi = {10.1074/jbc.M113.514521}, pages = {34767 -- 34776}, abstract = {Aromatic peroxygenases (APOs) represent a unique oxidoreductase sub-subclass of heme proteins with peroxygenase and peroxidase activity and were thus recently assigned a distinct EC classification (EC 1.11.2.1). They catalyze, inter alia, oxyfunctionalization reactions of aromatic and aliphatic hydrocarbons with remarkable regio- and stereoselectivities. When compared with cytochrome P450, APOs appear to be the choice enzymes for oxyfunctionalizations in organic synthesis due to their independence from a cellular environment and their greater chemical versatility. Here, the first two crystal structures of a heavily glycosylated fungal aromatic peroxygenase (AaeAPO) are described. They reveal different pH-dependent ligand binding modes. We model the fitting of various substrates in AaeAPO, illustrating the way the enzyme oxygenates polycyclic aromatic hydrocarbons. Spatial restrictions by a phenylalanine pentad in the active-site environment govern substrate specificity in AaeAPO.}, language = {en} }