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Crystal structure of the lignin peroxidase (ApeLiP) from Agrocybe pediadesCrystal structure of the lignin peroxidase (ApeLiP) from Agrocybe pediades
Structural highlights
Publication Abstract from PubMedLignin 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. See AlsoReferences
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