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 -