Exploring the catalase activity of unspecific peroxygenases and the mechanism of peroxide-dependent heme destruction

  • 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 inThe 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.show moreshow less

Export metadata

Additional Services

Search Google Scholar
Metadaten
Author: Alexander Karich, Katrin Scheibner, René UllrichORCiD, Martin HofrichterORCiD
URL:http://www.sciencedirect.com/science/article/pii/S1381117716302090
DOI:https://doi.org/10.1016/j.molcatb.2016.10.014
ISSN:1381-1177
Title of the source (English):Journal of Molecular Catalysis B: Enzymatic
Document Type:Scientific journal article peer-reviewed
Language:English
Year of publication:2016
Tag:Peroxygenase
Volume/Year:134
Issue number:A
First Page:238
Last Page:246
Faculty/Chair:Fakultät 2 Umwelt und Naturwissenschaften / FG Enzymtechnologie
Einverstanden ✔
Diese Webseite verwendet technisch erforderliche Session-Cookies. Durch die weitere Nutzung der Webseite stimmen Sie diesem zu. Unsere Datenschutzerklärung finden Sie hier.