@misc{KlugeUllrichDolgeetal., author = {Kluge, Martin and Ullrich, Ren{\´e} and Dolge, Christoph and Scheibner, Katrin and Hofrichter, Martin}, title = {Hydroxylation of naphthalene by aromatic peroxygenase from Agrocybe aegerita proceeds via oxygen transfer from H2O2 and intermediary epoxidation}, series = {Applied Microbiology and Biotechnology}, volume = {81}, journal = {Applied Microbiology and Biotechnology}, number = {6}, issn = {0175-7598}, doi = {10.1007/s00253-008-1704-y}, pages = {1071 -- 1076}, abstract = {Agrocybe aegerita peroxidase/peroxygenase (AaP) is an extracellular fungal biocatalyst that selectively hydroxylates the aromatic ring of naphthalene. Under alkaline conditions, the reaction proceeds via the formation of an intermediary product with a molecular mass of 144 and a characteristic UV absorption spectrum (A max 210, 267, and 303 nm). The compound was semistable at pH 9 but spontaneously hydrolyzed under acidic conditions (pH <7) into 1-naphthol as major product and traces of 2-naphthol. Based on these findings and literature data, we propose naphthalene 1,2-oxide as the primary product of AaP-catalyzed oxygenation of naphthalene. Using 18O-labeled hydrogen peroxide, the origin of the oxygen atom transferred to naphthalene was proved to be the peroxide that acts both as oxidant (primary electron acceptor) and oxygen source.}, language = {en} } @misc{PorajKobielskaKinneUllrichetal., author = {Poraj-Kobielska, Marzena and Kinne, Matthias and Ullrich, Ren{\´e} and Scheibner, Katrin and Hofrichter, Martin}, title = {A spectrophotometric assay for the detection of fungal peroxygenases}, series = {Analytical Biochemistry}, volume = {421}, journal = {Analytical Biochemistry}, number = {1}, doi = {10.1016/j.ab.2011.10.009}, pages = {327 -- 329}, abstract = {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.}, language = {en} } @misc{UllrichPorajKobielskaScholzeetal., author = {Ullrich, Ren{\´e} and Poraj-Kobielska, Marzena and Scholze, Steffi and Halbout, Claire and Sandvoss, Martin and Pecyna, Marek J. and Scheibner, Katrin and Hofrichter, Martin}, title = {Side chain removal from corticosteroids by unspecific peroxygenase}, series = {Journal of Inorganic Biochemistry}, volume = {183}, journal = {Journal of Inorganic Biochemistry}, issn = {1873-3344}, doi = {10.1016/j.jinorgbio.2018.03.011}, pages = {84 -- 93}, abstract = {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.}, language = {en} }