doi:10.3390/antiox10091446engSánchez-Ruiz, María IsabelAyuso Fernández, IvánRencoret, JorgeGonzález Ramírez, Andrés ManuelLinde, DoloresDavó Siguero, IreneRomero, AntonioGutiérrez, AnaMartínez, Angel T.Ruiz Dueñas, Francisco JavierAgaricales mushroom lignin peroxidase: from structure–function to degradative capabilitiesART-2021-131282Lignin biodegradation has been extensively studied in white-rot fungi, which largely belong to order Polyporales. Among the enzymes that wood-rotting polypores secrete, lignin peroxidases (LiPs) have been labeled as the most efficient. Here, we characterize a similar enzyme (ApeLiP) from a fungus of the order Agaricales (with ~13,000 described species), the soil-inhabiting mushroom Agrocybe pediades. X-ray crystallography revealed that ApeLiP is structurally related to Polyporales LiPs, with a conserved heme-pocket and a solvent-exposed tryptophan. Its biochemical characterization shows that ApeLiP can oxidize both phenolic and non-phenolic lignin model-compounds, as well as different dyes. Moreover, using stopped-flow rapid spectrophotometry and 2D-NMR, we demonstrate that ApeLiP can also act on real lignin. Characterization of a variant lacking the above tryptophan residue shows that this is the oxidation site for lignin and other high redox-potential substrates, and also plays a role in phenolic substrate oxidation. The reduction potentials of the catalytic-cycle intermediates were estimated by stopped-flow in equilibrium reactions, showing similar activation by H2O2, but a lower potential for the rate-limiting step (compound-II reduction) compared to other LiPs. Unexpectedly, ApeLiP was stable from acidic to basic pH, a relevant feature for application considering its different optima for oxidation of phenolic and nonphenolic compounds.2021http://zaguan.unizar.es/record/12117010.3390/antiox10091446http://zaguan.unizar.es/record/121170oai:zaguan.unizar.es:121170info:eu-repo/grantAgreement/ES/CSIC/PIE-202120E019info:eu-repo/grantAgreement/ES/MCIN/FEDER/BIO2017-86559-RAntioxidants 10, 9 (2021), 1446 [23 pp]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess