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 - 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 - TY - CHAP A1 - Hofrichter, Martin A1 - Kellner, Harald A1 - Herzog, Robert A1 - Karich, Alexander A1 - Liers, Christiane A1 - Scheibner, Katrin A1 - Kimani, Virginia Wambui A1 - Ullrich, René ED - Nevalainen, Helena T1 - Fungal Peroxygenases: A Phylogenetically Old Superfamily of Heme Enzymes with Promiscuity for Oxygen Transfer Reactions. T2 - Grand Challenges in Fungal Biotechnology KW - Peroxygenase Y1 - 2020 SN - 978-3-030-29540-0 SN - 978-3-030-29541-7 U6 - https://doi.org/10.1007/978-3-030-29541-7 SN - 2367-1017 SN - 2367-1025 SP - 369 EP - 403 PB - Springer Nature CY - Cham ET - 1. Auflage ER - TY - GEN A1 - Hofrichter, Martin A1 - Kellner, Harald A1 - Herzog, Robert A1 - Karich, Alexander A1 - Kiebist, Jan A1 - Scheibner, Katrin A1 - Ullrich, René T1 - Peroxide-Mediated Oxygenation of Organic Compounds by Fungal Peroxygenases T2 - Antioxidants N2 - Unspecific peroxygenases (UPOs), whose sequences can be found in the genomes of thousands of filamentous fungi, many yeasts and certain fungus-like protists, are fascinating biocatalysts that transfer peroxide-borne oxygen (from H2O2 or R-OOH) with high efficiency to a wide range of organic substrates, including less or unactivated carbons and heteroatoms. A twice-proline-flanked cysteine (PCP motif) typically ligates the heme that forms the heart of the active site of UPOs and enables various types of relevant oxygenation reactions (hydroxylation, epoxidation, subsequent dealkylations, deacylation, or aromatization) together with less specific one-electron oxidations (e.g., phenoxy radical formation). In consequence, the substrate portfolio of a UPO enzyme always combines prototypical monooxygenase and peroxidase activities. Here, we briefly review nearly 20 years of peroxygenase research, considering basic mechanistic, molecular, phylogenetic, and biotechnological aspects. KW - unspecific peroxygenase KW - monooxygenase KW - peroxidases KW - hydroxylation KW - epoxidation KW - dealkylation Y1 - 2022 UR - https://www.mdpi.com/2076-3921/11/1/163 U6 - https://doi.org/10.3390/antiox11010163 SN - 2076-3921 VL - 11 IS - 1 SP - 1 EP - 21 ER - TY - GEN A1 - Karich, Alexander A1 - Cai, Hongtao A1 - Linhardt, Anne A1 - Antony, Anila A1 - Liers, Christiane A1 - Ullrich, René A1 - Schwaderer, Fabian A1 - Kalmbach, Johannes A1 - Scheibner, Katrin A1 - Hofrichter, Martin A1 - Synytska, Alla T1 - Conductive hairy particles with homogeneous and Janus design as carrier materials for the efficient immobilization of unspecific peroxygenases T2 - Biotechnology journal : systems & synthetic biology, nanobiotech, medicine N2 - Efficient immobilization of unspecific peroxygenases (UPOs) on hairy particles with homogeneous and Janus design possessingconductive core and polymeric shell was demonstrated. PDMAEMA brushes (hairs) with controlled chain lengths weresuccessfully grown from the conductive silver particles allowing further immobilization of enzymes and keeping their activity.The Janus design of the synthesized particles maintained the conductivity of the core material. Enzyme immobilization onbrush-modified particles was first carried out with two laccases as model enzymes [Trametes versicolor (TveLac) and Pycnoporuscinnabarinus (PciLac)] and then successfully extended to UPOs [two wild-type and one recombinant UPO from Marasmius rotula(MroUPO) and Agrocybe aegerita (AaeUPO, rAaeUPO)]. The most efficient immobilization was achieved for MroUPO on Janusparticles. The enzyme loading is reversible and could be successfully repeated after cleaning of the particles. Thus, the successfulimmobilization of an MroUPO on conductive hairy Janus particles was demonstrated for the first time. The major advantage ofthe proposed approach lies in the reusability of the enzyme and its carrier, as well as in the use of conductive core materials, whichcould be promising, for example, as material for electrochemical biosensors in future. KW - Ag particles KW - Core shell particles KW - Enzyme immobilization KW - Janus particles KW - PDMAEMA KW - Polymer brushes KW - Unspecific peroxygenases Y1 - 2025 U6 - https://doi.org/10.1002/biot.70078 SN - 1860-7314 VL - 20 IS - 7 SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim ER -