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Publication Abstract from PubMed

Lignin 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.

Agaricales Mushroom Lignin Peroxidase: From Structure-Function to Degradative Capabilities.,Sanchez-Ruiz MI, Ayuso-Fernandez I, Rencoret J, Gonzalez-Ramirez AM, Linde D, Davo-Siguero I, Romero A, Gutierrez A, Martinez AT, Ruiz-Duenas FJ Antioxidants (Basel). 2021 Sep 12;10(9). pii: antiox10091446. doi:, 10.3390/antiox10091446. PMID:34573078^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.