TY - GEN A1 - Peter, Sebastian A1 - Karich, Alexander A1 - Ullrich, René A1 - Gröbe, Glenn A1 - Scheibner, Katrin A1 - Hofrichter, Martin T1 - Enzymatic one-pot conversion of cyclohexane into cyclohexanone: Comparison of four fungal peroxygenases T2 - Journal of Molecular Catalysis : B, Enzymatic N2 - 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. KW - cyclohexane KW - cyclohexanol KW - cyclohexanone KW - UPO KW - Peroxygenase Y1 - 2014 UR - http://www.sciencedirect.com/science/article/pii/S138111771300266X U6 - https://doi.org/10.1016/j.molcatb.2013.09.016 IS - 103 SP - 47 EP - 51 ER - TY - GEN A1 - Poraj-Kobielska, Marzena A1 - Kinne, Matthias A1 - Ullrich, René A1 - Scheibner, Katrin A1 - Hofrichter, Martin T1 - A spectrophotometric assay for the detection of fungal peroxygenases T2 - Analytical Biochemistry N2 - Rapid and simple spectrophotometric methods are required for the unambiguous detection of recently discovered fungal peroxygenases in vivo and in vitro. This paper describes a peroxygenase-specific assay using 5-nitro-1,3-benzodioxole as substrate. The product, 4-nitrocatechol, produces a yellow color at pH 7, which can be followed over time at 425 nm (ε425 = 9,700 M−1 cm−1), and a red color when adjusted to pH >12, which can be measured in form of an end-point determination at 514 nm (ε514 = 11,400 M−1 cm−1). The assay is suitable for detecting peroxygenase activities in complex growth media and environmental samples as well as for high-throughput screenings. KW - Monooxygenase KW - Peroxidase KW - Heme-thiolate KW - P450 KW - Chloroperoxidase KW - 5-Nitro-1,3-benzodioxole Y1 - 2012 UR - http://www.sciencedirect.com/science/article/pii/S0003269711006610 UR - 1096-0309 U6 - https://doi.org/10.1016/j.ab.2011.10.009 VL - 421 IS - 1 SP - 327 EP - 329 ER - TY - GEN A1 - Ullrich, René A1 - Nüske, Jörg A1 - Scheibner, Katrin A1 - Spantzel, Jörg A1 - Hofrichter, Martin T1 - Novel Haloperoxidase from the Agaric Basidiomycete Agrocybe aegerita Oxidizes Aryl Alcohols and Aldehydes T2 - Applied and Environmental Microbiology N2 - Agrocybe aegerita, a bark mulch- and wood-colonizing basidiomycete, was found to produce a peroxidase (AaP) that oxidizes aryl alcohols, such as veratryl and benzyl alcohols, into the corresponding aldehydes and then into benzoic acids. The enzyme also catalyzed the oxidation of typical peroxidase substrates, such as 2,6-dimethoxyphenol (DMP) or 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS). A. aegerita peroxidase production depended on the concentration of organic nitrogen in the medium, and highest enzyme levels were detected in the presence of soybean meal. Two fractions of the enzyme, AaP I and AaP II, which had identical molecular masses (46 kDa) and isoelectric points of 4.6 to 5.4 and 4.9 to 5.6, respectively (corresponding to six different isoforms), were identified after several steps of purification, including anion- and cation-exchange chromatography. The optimum pH for the oxidation of aryl alcohols was found to be around 7, and the enzyme required relatively high concentrations of H2O2 (2 mM) for optimum activity. The apparent Km values for ABTS, DMP, benzyl alcohol, veratryl alcohol, and H2O2 were 37, 298, 1,001, 2,367 and 1,313 μM, respectively. The N-terminal amino acid sequences of the main AaP II spots blotted after two-dimensional gel electrophoresis were almost identical and exhibited almost no homology to the sequences of other peroxidases from basidiomycetes, but they shared the first three amino acids, as well as two additional amino acids, with the heme chloroperoxidase (CPO) from the ascomycete Caldariomyces fumago. This finding is consistent with the fact that AaP halogenates monochlorodimedone, the specific substrate of CPO. The existence of haloperoxidases in basidiomycetous fungi may be of general significance for the natural formation of chlorinated organic compounds in forest soils. KW - Agrocybe aegerita KW - Peroxygenase KW - Peroxidase KW - Basidiomycete Y1 - 2004 UR - http://aem.asm.org/content/70/8/4575.long U6 - https://doi.org/10.1128/AEM.70.8.4575-4581.2004 SN - 1098-5336 VL - 70 IS - 8 SP - 4575 EP - 4581 ER - TY - GEN A1 - Martínez, Angel T. A1 - Ruiz-Dueñas, Francisco J. A1 - Gutiérrez, Ana A1 - Río, José C. del A1 - Alcalde, Miguel A1 - Liers, Christiane A1 - Ullrich, René A1 - Hofrichter, Martin A1 - Scheibner, Katrin A1 - Kalum, Lisbeth A1 - Vind, Jesper A1 - Lund, Henrik T1 - Search, engineering, and applications of new oxidative biocatalysts T2 - Biofuels, Bioproducts and Biorefining N2 - Most industrial enzymes are hydrolases, such as glycosidases and esterases. However, oxidoreductases have an unexploited potential for substituting harsh (and scarcely selective) chemical processes. A group of basidiomycetes are the only organisms degrading the aromatic lignin polymer, enabling the subsequent use of plant polysaccharides. Therefore, these fungi and their ligninolytic peroxidases are the biocatalysts of choice for industrial delignification and oxidative biotransformations of aromatic and other organic compounds. The latter also include oxygenation reactions, which are catalyzed with high regio/stereo selectivity by fungal peroxygenases. In search for novel and more robust peroxidases/peroxygenases, basidiomycetes from unexplored habitats were screened, and hundreds of genes identified in basidiomycete genomes (in collaboration with the DOE JGI). The most interesting genes were heterologously expressed, and the corresponding enzymes structurally-functionally characterized. The information obtained enabled us to improve the enzyme operational and catalytic properties by directed mutagenesis. However, the structural-functional relationships explaining some desirable properties are not established yet and, therefore, their introduction was addressed by ‘non-rational’ directed evolution. Then, over 100 oxidative biotransformations were analyzed. Among them, it is noteworthy to mention the regio/stereo selective hydroxylation of long/short-chain alkanes (a chemically challenging reaction), epoxidation of alkenes, and production of hydroxy-fatty acids. Concerning aromatic oxygenations, the regioselective hydroxylation of flavonoids, and stereoselective hydroxylation/epoxidation of alkyl/alkenyl-benzenes were among the most remarkable reactions, together with enzymatic hydroxylation of benzene (as an alternative for harsh chemical process). Finally, peroxidases and peroxygenases also showed a potential as delignification biocatalysts and in the decolorization of contaminant dyes from textile industries. KW - peroxygenases KW - peroxidases KW - lignin degradation KW - oxidative industrial biocatalysts KW - enzyme rational design KW - directed enzyme evolution KW - selective oxygenation Y1 - 2014 UR - http://onlinelibrary.wiley.com/doi/10.1002/bbb.1498/abstract U6 - https://doi.org/10.1002/bbb.1498 SN - 1932-1031 VL - 8 IS - 6 SP - 819 EP - 835 ER - TY - PAT A1 - Poraj-Kobielska, Marzena A1 - Scheibner, Katrin A1 - Gröbe, Glenn A1 - Kiebist, Jan A1 - Grün, Manfred A1 - Ullrich, René A1 - Hofrichter, Martin T1 - Verfahren zur Deacylierung von Corticoiden Y1 - 2014 ER - TY - GEN A1 - Babot, Esteban D. A1 - Río, José C. del A1 - Cañellas, Marina A1 - Sancho, Ferran A1 - Lucas, Fátima A1 - Guallar, Víctor A1 - Kalum, Lisbeth A1 - Lund, Henrik A1 - Gröbe, Glenn A1 - Scheibner, Katrin A1 - Ullrich, René A1 - Hofrichter, Martin A1 - Martínez, Angel T. A1 - Gutiérrez, Ana T1 - Steroid hydroxylation by basidiomycete peroxygenases: A combined experimental and computational study T2 - Applied and Environmental Microbiology N2 - The goal of this study is the selective oxyfunctionalization of steroids under mild and environmentally-friendly conditions using fungal enzymes. With this purpose, peroxygenases from three basidiomycete species were tested for hydroxylation of a variety of steroidal compounds, using H2O2 as the only cosubstrate. Two of them are wild-type enzymes from Agrocybe aegerita and Marasmius rotula, and the third one is a recombinant enzyme from Coprinopsis cinerea. The enzymatic reactions on free and esterified sterols, and steroid hydrocarbons and ketones were followed by gas chromatography, and the products were identified by mass spectrometry. Hydroxylation at the side chain over the steroidal rings was preferred, with the 25-hydroxyderivatives predominating (interestingly antiviral and other biological activities of 25-hydroxycholesterol have been recently reported). However, hydroxylation in the ring moiety and terminal hydroxylation at the side-chain was also observed in some steroids, the former favored by the absence of oxygenated groups at C3 and by the presence of conjugated double bonds in the rings. To understand the yield and selectivity differences between the different steroids, a computational study was performed using Protein Energy Landscape Exploration (PELE) software for dynamic ligand diffusion. These simulations showed that the active site geometry and hydrophobicity favors the entrance of the steroid side-chain, while the entrance of the ring is energetically penalized. Also, a direct correlation between the conversion rate and the side-chain entrance ratio could be established, that explains the varying reaction yields observed. KW - Peroxyenase Y1 - 2015 UR - http://aem.asm.org/content/early/2015/04/08/AEM.00660-15 U6 - https://doi.org/10.1128/AEM.00660-15 SN - 0099-2240 SN - 1098-5336 VL - 81 IS - 12 SP - 4130 EP - 4142 ER - TY - GEN A1 - Poraj-Kobielska, Marzena A1 - Peter, Sebastian A1 - Leonhardt, Sabrina A1 - Ullrich, René A1 - Scheibner, Katrin A1 - Hofrichter, Martin T1 - Immobilization of unspecific peroxygenases (EC 1.11.2.1) in PVA/PEG gel and hollow fiber modules T2 - Biochemical Engineering Journal N2 - The immobilization of enzymes has many advantages, such as higher stability, easier handling, and reuse of the catalyst. Here we report, for the first time, two effective methods for the immobilization of unspecific peroxygenase (UPO; EC 1.11.2.1). This biocatalyst type comprises heavily glycosylated heme-thiolate proteins that catalyze various biotechnologically relevant oxyfunctionalizations. Both the encapsulation in cryogel and the retention of the enzyme in hollow fiber modules were found to be efficient methods for their immobilization. After encapsulation, the enzyme still exhibited 60% of its initial activity. Interestingly, we did not find differences in the kinetic parameters of free and immobilized UPOs. In long-term experiments, the conversion of the pharmaceutical diclofenac with immobilized UPOs in different reactor types yielded between 62 mg and 154 mg of the major human drug metabolite 4′-hydroxydiclofenac. The maximal total turnover number was about 60-fold higher compared to the free enzyme. A test over 5 months showed that storage of encapsulated UPOs in non-polar solvents (e.g., cyclohexane) helps to preserve the enzyme stability and increases their relative activity (by about ∼150%, in the case of diclofenac hydroxylation). In addition to the hydrophilic substrate diclofenac, encapsulated UPOs also oxidized the hydrophobic model compound cyclohexane. KW - Peroxygenase Y1 - 2015 UR - http://www.sciencedirect.com/science/article/pii/S1369703X15000820 U6 - https://doi.org/10.1016/j.bej.2015.02.037 SN - 1369-703X VL - 98 SP - 144 EP - 150 ER - TY - GEN A1 - Kiebist, Jan A1 - Schmidtke, Kai-Uwe A1 - Zimmermann, Jörg A1 - Kellner, Harald A1 - Jehmlich, Nico A1 - Ullrich, René A1 - Zänder, Daniel A1 - Hofrichter, Martin A1 - Scheibner, Katrin T1 - A peroxygenase from Chaetomium globosum catalyzes the selective oxygenation of testosterone T2 - ChemBioChem N2 - Unspecific peroxygenases (UPO, EC 1.11.2.1) secreted by fungi open an efficient way to selectively oxyfunctionalize diverse organic substrates including less activated hydrocarbons by transferring peroxide-borne oxygen. Herein, we investigated a cell-free approach to incorporate epoxy and hydroxyl functionalities directly into the bulky molecule of testosterone by a novel unspecific peroxygenase that was produced by the ascomycetous fungus Chaetomium globosum in a complex medium rich in carbon and nitrogen. Purification by fast protein liquid chromatography revealed two enzyme fractions with the same molecular mass of 36 kDa and specific activities of 4.4 to 12 U mg-1. Whereas well-known UPOs of Agrocybe aegerita (AaeUPO) and Marasmius rotula (MroUPO) failed to convert testosterone in a comparative study, the UPO of C. globosum (CglUPO) accepted testosterone as substrate and converted it with up to 7,000 total turnovers (TTN) into two oxygenated products: the 4,5-epoxide of testosterone in β-configuration and 16α-hydroxytestosterone. The reaction was performed at 100-mg scale resulting in the formation of about 90 % of the epoxide and 10 % of the hydroxylation product, which both could be isolated with purities above 96 %. Thus, CglUPO may be a promising biocatalyst for the oxyfunctionalization of bulky steroids and provide a useful tool for the synthesis of pharmaceutically relevant steroidal molecules. KW - peroxidase KW - hydroxylation Y1 - 2017 UR - http://onlinelibrary.wiley.com/doi/10.1002/cbic.201600677/abstract U6 - https://doi.org/10.1002/cbic.201600677 SN - 1439-7633 VL - 18 IS - 6 SP - 563 EP - 569 ER - TY - GEN A1 - Karich, Alexander A1 - Scheibner, Katrin A1 - Ullrich, René A1 - Hofrichter, Martin T1 - Exploring the catalase activity of unspecific peroxygenases and the mechanism of peroxide-dependent heme destruction T2 - Journal of Molecular Catalysis B: Enzymatic N2 - The catalase activity of three unspecific peroxygenases (UPOs) from the agaric basidiomycetes Agrocybe aegerita, Coprinopsis cinerea and Marasmius rotula was investigated. The study included analysis of pH dependency of the catalase reaction and H₂O₂ mediated enzyme inactivation as well as experiments on the influence of a second substrate on the course of catalase reaction. Apparent kinetic parameters (Km, kcat) for the catalase activity of UPOs were determined. Inactivation of UPOs by H₂O₂ is discussed with regard to O₂ production and remaining UPO activity. Furthermore formation of biliverdin as heme destruction product was demonstrated along with the formation of UPO compound III as a possible intermediate that forces the destruction process. Radical trapping experiments with methyl benzoate gave indication for the formation of hydroxyl radicals in the presence of excess H₂O₂. Eventually, a plausible pathway of heme destruction has been proposed, proceeding via UPO compound III and subsequent hydroxyl radical formation, which in turn may cause heme bleaching and verdoheme and biliverdin formation. KW - Peroxygenase Y1 - 2016 UR - http://www.sciencedirect.com/science/article/pii/S1381117716302090 U6 - https://doi.org/10.1016/j.molcatb.2016.10.014 SN - 1381-1177 VL - 134 IS - A SP - 238 EP - 246 ER - TY - GEN A1 - Karich, Alexander A1 - Ullrich, René A1 - Scheibner, Katrin A1 - Hofrichter, Martin T1 - Fungal unspecific peroxygenases oxidize the majority of organic EPA priority pollutants T2 - Frontiers in Microbiology N2 - Unspecific peroxygenases (UPOs) are secreted fungal enzymes with promiscuity for oxygen transfer and oxidation reactions. Functionally, they represent hybrids of P450 monooxygenases and heme peroxidases; phylogenetically they belong to the family of heme-thiolate peroxidases. Two UPOs from the basidiomycetous fungi Agrocybe aegerita (AaeUPO) and Marasmius rotula (MroUPO) converted 35 out of 40 compounds listed as EPA priority pollutants, including chlorinated benzenes and their derivatives, halogenated biphenyl ethers, nitroaromatic compounds, polycyclic aromatic hydrocarbons (PAHs) and phthalic acid derivatives. These oxygenations and oxidations resulted in diverse products and-if at all-were limited for three reasons: (i) steric hindrance caused by multiple substitutions or bulkiness of the compound as such (e.g., hexachlorobenzene or large PAHs), (ii) strong inactivation of aromatic rings (e.g., nitrobenzene), and (iii) low water solubility (e.g., complex arenes). The general outcome of our study is that UPOs can be considered as extracellular counterparts of intracellular monooxygenases, both with respect to catalyzed reactions and catalytic versatility. Therefore, they should be taken into consideration as a relevant biocatalytic detoxification and biodegradation tool used by fungi when confronted with toxins, xenobiotics and pollutants in their natural environments. KW - Peroxygenase Y1 - 2017 UR - https://www.frontiersin.org/articles/10.3389/fmicb.2017.01463/full U6 - https://doi.org/10.3389/fmicb.2017.01463 SN - 1664-302X VL - 8 ER -