TY - GEN A1 - Ullrich, René A1 - Poraj-Kobielska, Marzena A1 - Scholze, Steffi A1 - Halbout, Claire A1 - Sandvoss, Martin A1 - Pecyna, Marek J. A1 - Scheibner, Katrin A1 - Hofrichter, Martin T1 - Side chain removal from corticosteroids by unspecific peroxygenase T2 - Journal of Inorganic Biochemistry N2 - Two unspecific peroxygenases (UPO, EC 1.11.2.1) from the basidiomycetous fungi Marasmius rotula and Marasmius wettsteinii oxidized steroids with hydroxyacetyl and hydroxyl functionalities at C17 - such as cortisone, Reichstein's substance S and prednisone - via stepwise oxygenation and final fission of the side chain. The sequential oxidation started with the hydroxylation of the terminal carbon (C21) leading to a stable geminal alcohol (e.g. cortisone 21-gem-diol) and proceeded via a second oxygenation resulting in the corresponding α-ketocarboxylic acid (e.g. cortisone 21-oic acid). The latter decomposed under formation of adrenosterone (4-androstene-3,11,17-trione) as well as formic acid and carbonic acid (that is in equilibrium with carbon dioxide); fission products comprising two carbon atoms such as glycolic acid or glyoxylic acid were not detected. Protein models based on the crystal structure data of MroUPO (Marasmius rotula unspecific peroxygenase) revealed that the bulky cortisone molecule suitably fits into the enzyme's access channel, which enables the heme iron to come in close contact to the carbons (C21, C20) of the steroidal side chain. ICP-MS analysis of purified MroUPO confirmed the presence of magnesium supposedly stabilizing the porphyrin ring system. KW - Peroxygenation KW - Peroxygenase KW - P450 KW - Deacylation Y1 - 2018 U6 - https://doi.org/10.1016/j.jinorgbio.2018.03.011 SN - 1873-3344 SN - 0162-0134 VL - 183 SP - 84 EP - 93 ER - TY - GEN A1 - Aranda, Carmen A1 - Ullrich, René A1 - Kiebist, Jan A1 - Scheibner, Katrin A1 - Río, José C. del A1 - Hofrichter, Martin A1 - Martínez, Angel T. A1 - Gutiérrez, Ana T1 - Selective synthesis of the resveratrol analogue 4,4′-dihydroxy-trans-stilbene and stilbenoids modification by fungal peroxygenases T2 - Catalysis Science & Technology N2 - This work gives first evidence that the unspecific peroxygenases (UPOs) from the basidiomycetes Agrocybe aegerita (AaeUPO), Coprinopsis cinerea (rCciUPO) and Marasmius rotula (MroUPO) are able to catalyze the regioselective hydroxylation of trans-stilbene to 4,4′-dihydroxy-trans-stilbene (DHS), a resveratrol (RSV) analogue whose preventive effects on cancer invasion and metastasis have very recently been shown. Nearly complete transformation of substrate (yielding DHS) was achieved with the three enzymes tested, using H2O2 as the only co-substrate, with AaeUPO showing exceptionally higher total turnover number (200 000) than MroUPO (26 000) and rCciUPO (1400). Kinetic studies demonstrated that AaeUPO was the most efficient enzyme catalyzing stilbene dihydroxylation with catalytic efficiencies (kcat/Km) one and two orders of magnitude higher than those of MroUPO and rCciUPO, so that 4-hydroxystilbene appears to be the best UPO substrate reported to date. In contrast, the peroxygenase from the ascomycete Chaetomium globosum (CglUPO) failed to hydroxylate trans-stilbene at the aromatic ring and instead produced the trans-epoxide in the alkenyl moiety. In addition, stilbenoids such as pinosylvin (Pin) and RSV were tested as substrates for the enzymatic synthesis of RSV from Pin and oxyresveratrol (oxyRSV) from both RSV and Pin. Overall, lower conversion rates and regioselectivities compared with trans-stilbene were accomplished by three of the UPOs, and no conversion was observed with CglUPO. The highest amount of RSV (63% of products) and oxyRSV (78%) were again attained with AaeUPO. True peroxygenase activity was demonstrated by incorporation of 18O from H218O2 into the stilbene hydroxylation products. Differences in the number of phenylalanine residues at the heme access channels seems related to differences in aromatic hydroxylation activity, since they would facilitate substrate positioning by aromatic-aromatic interactions. The only ascomycete UPO tested (that of C. globosum) turned out to have the most differing active site (distal side of heme cavity) and reactivity with stilbenes resulting in ethenyl epoxidation instead of aromatic hydroxylation. The above oxyfunctionalizations by fungal UPOs represent a novel and simple alternative to chemical synthesis for the production of DHS, RSV and oxyRSV. KW - Peroxygenase Y1 - 2018 U6 - https://doi.org/10.1039/C8CY00272J SN - 2044-4761 SN - 2044-4753 VL - 9 IS - 8 SP - 2394 EP - 2401 ER -