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Natural Syringyl Mediators Accelerate Laccase-Catalyzed β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl Model Substrate via an Aggregation Mechanism
[Image: see text] Laccase–mediator systems (LMSs) have been intensively investigated in lignin degradation. Although only natural metabolites are available for fungal lignin degradation, mediator molecules from metabolites have received substantially less attention than artificial organic–synthetic...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8427646/ https://www.ncbi.nlm.nih.gov/pubmed/34514230 http://dx.doi.org/10.1021/acsomega.1c02501 |
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author | Chen, Xu Ouyang, Xingyu Li, Jiayi Zhao, Yi-Lei |
author_facet | Chen, Xu Ouyang, Xingyu Li, Jiayi Zhao, Yi-Lei |
author_sort | Chen, Xu |
collection | PubMed |
description | [Image: see text] Laccase–mediator systems (LMSs) have been intensively investigated in lignin degradation. Although only natural metabolites are available for fungal lignin degradation, mediator molecules from metabolites have received substantially less attention than artificial organic–synthetic compounds. It remains unclear which metabolites can accelerate laccase-catalyzed reactions and how those natural mediators influence lignin degradation. In this work, we evaluated Trametes versicolor laccase-catalyzed reaction kinetics on a lignin guaiacyl subunit model (guaiacylglycerol-β-guaiacyl ether, G-β-GE) in the presence of a group of lignin syringyl subunit molecules: syringaldehyde, acetosyringone, and methyl syringate. We then compare their performance to a well-known synthetic mediator ABTS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid). Time-resolved UPLC-TOF-MS revealed that the syringyl mediators were more effective in accelerating the β-O-4 cleavage and Cα-oxidation of G-β-GE than ABTS under laccase-catalysis, despite the syringyl compounds possessing slower individual oxidation rates. In addition, the product profile of polymerization was also promoted dramatically, compared to that of the ABTS/laccase system. The LMS kinetic modeling suggested that mediator–substrate aggregation played a critical role in the laccase–mediator system; in which, the lignin syringyl and guaiacyl subunits likely form a π–π stacking van der Waals complex that can be oxidized faster than the syringyl or guaiacyl monomers by themselves. This syringyl–guaiacyl aggregation hypothesis postulates that the weak interactions in lignin biopolymers are able to accelerate the laccase-catalyzed biodegradation. |
format | Online Article Text |
id | pubmed-8427646 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-84276462021-09-10 Natural Syringyl Mediators Accelerate Laccase-Catalyzed β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl Model Substrate via an Aggregation Mechanism Chen, Xu Ouyang, Xingyu Li, Jiayi Zhao, Yi-Lei ACS Omega [Image: see text] Laccase–mediator systems (LMSs) have been intensively investigated in lignin degradation. Although only natural metabolites are available for fungal lignin degradation, mediator molecules from metabolites have received substantially less attention than artificial organic–synthetic compounds. It remains unclear which metabolites can accelerate laccase-catalyzed reactions and how those natural mediators influence lignin degradation. In this work, we evaluated Trametes versicolor laccase-catalyzed reaction kinetics on a lignin guaiacyl subunit model (guaiacylglycerol-β-guaiacyl ether, G-β-GE) in the presence of a group of lignin syringyl subunit molecules: syringaldehyde, acetosyringone, and methyl syringate. We then compare their performance to a well-known synthetic mediator ABTS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid). Time-resolved UPLC-TOF-MS revealed that the syringyl mediators were more effective in accelerating the β-O-4 cleavage and Cα-oxidation of G-β-GE than ABTS under laccase-catalysis, despite the syringyl compounds possessing slower individual oxidation rates. In addition, the product profile of polymerization was also promoted dramatically, compared to that of the ABTS/laccase system. The LMS kinetic modeling suggested that mediator–substrate aggregation played a critical role in the laccase–mediator system; in which, the lignin syringyl and guaiacyl subunits likely form a π–π stacking van der Waals complex that can be oxidized faster than the syringyl or guaiacyl monomers by themselves. This syringyl–guaiacyl aggregation hypothesis postulates that the weak interactions in lignin biopolymers are able to accelerate the laccase-catalyzed biodegradation. American Chemical Society 2021-08-04 /pmc/articles/PMC8427646/ /pubmed/34514230 http://dx.doi.org/10.1021/acsomega.1c02501 Text en © 2021 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by-nc-nd/4.0/Permits non-commercial access and re-use, provided that author attribution and integrity are maintained; but does not permit creation of adaptations or other derivative works (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
spellingShingle | Chen, Xu Ouyang, Xingyu Li, Jiayi Zhao, Yi-Lei Natural Syringyl Mediators Accelerate Laccase-Catalyzed β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl Model Substrate via an Aggregation Mechanism |
title | Natural Syringyl Mediators Accelerate Laccase-Catalyzed
β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl
Model Substrate via an Aggregation Mechanism |
title_full | Natural Syringyl Mediators Accelerate Laccase-Catalyzed
β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl
Model Substrate via an Aggregation Mechanism |
title_fullStr | Natural Syringyl Mediators Accelerate Laccase-Catalyzed
β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl
Model Substrate via an Aggregation Mechanism |
title_full_unstemmed | Natural Syringyl Mediators Accelerate Laccase-Catalyzed
β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl
Model Substrate via an Aggregation Mechanism |
title_short | Natural Syringyl Mediators Accelerate Laccase-Catalyzed
β-O-4 Cleavage and Cα-Oxidation of a Guaiacyl
Model Substrate via an Aggregation Mechanism |
title_sort | natural syringyl mediators accelerate laccase-catalyzed
β-o-4 cleavage and cα-oxidation of a guaiacyl
model substrate via an aggregation mechanism |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8427646/ https://www.ncbi.nlm.nih.gov/pubmed/34514230 http://dx.doi.org/10.1021/acsomega.1c02501 |
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