1
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Chorozian K, Karnaouri A, Tryfona T, Kondyli NG, Karantonis A, Topakas E. Characterization of a novel AA16 lytic polysaccharide monooxygenase from Thermothelomyces thermophilus and comparison of biochemical properties with an LPMO from AA9 family. Carbohydr Polym 2024; 342:122387. [PMID: 39048228 DOI: 10.1016/j.carbpol.2024.122387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/01/2024] [Accepted: 06/07/2024] [Indexed: 07/27/2024]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes which are categorized in the CAZy database under auxiliary activities families AA9-11, 13, 14-17. Secreted by various microorganisms, they play a crucial role in carbon recycling, particularly in fungal saprotrophs. LPMOs oxidize polysaccharides through monooxygenase/peroxygenase activities and exhibit peroxidase and oxidase activities, with variations among different families. AA16, a newly identified LPMO family, is noteworthy due to limited studies on its members, thus rendering the characterization of AA16 enzymes vital for addressing controversies around their functions. This study focused on heterologous expression and biochemical study of an AA16 LPMO from Thermothelomyces thermophilus (formerly known as Myceliophthora thermophila), namely MtLPMO16A. Substrate specificity evaluation of MtLPMO16A showed oxidative cleavage of hemicellulosic substrates and no activity on cellulose, accompanied by a strong oxidase activity. A comparative analysis with an LPMO from AA9 family explored correlations between these families, while MtLPMO16A was shown to boost the activity of some AA9 family LPMOs. The results offer new insights into the AA16 family's action mode and microbial hemicellulose decomposition mechanisms in nature.
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Affiliation(s)
- Koar Chorozian
- Ιndustrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Greece
| | - Anthi Karnaouri
- Laboratory of General and Agricultural Microbiology, Department of Crop Science, Agricultural University of Athens, Athens 11855, Greece.
| | - Theodora Tryfona
- Department of Biochemistry, School of Biological Sciences, University of Cambridge, Cambridge CB2 1QW, UK
| | - Nefeli Georgaki Kondyli
- Ιndustrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Greece; Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15780, Greece
| | - Antonis Karantonis
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15780, Greece
| | - Evangelos Topakas
- Ιndustrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Greece.
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2
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Truong NH, Le TTH, Nguyen HD, Nguyen HT, Dao TK, Tran TMN, Tran HL, Nguyen DT, Nguyen TQ, Phan THT, Do TH, Phan NH, Ngo TCN, Vu VV. Sequence and structure analyses of lytic polysaccharide monooxygenases mined from metagenomic DNA of humus samples around white-rot fungi in Cuc Phuong tropical forest, Vietnam. PeerJ 2024; 12:e17553. [PMID: 38938609 PMCID: PMC11210479 DOI: 10.7717/peerj.17553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 05/20/2024] [Indexed: 06/29/2024] Open
Abstract
Background White-rot fungi and bacteria communities are unique ecosystems with different types of symbiotic interactions occurring during wood decomposition, such as cooperation, mutualism, nutritional competition, and antagonism. The role of chitin-active lytic polysaccharide monooxygenases (LPMOs) in these symbiotic interactions is the subject of this study. Method In this study, bioinformatics tools were used to analyze the sequence and structure of putative LPMOs mined by hidden Markov model (HMM) profiles from the bacterial metagenomic DNA database of collected humus samples around white-rot fungi in Cuc Phuong primary forest, Vietnam. Two genes encoding putative LPMOs were expressed in E. coli and purified for enzyme activity assay. Result Thirty-one full-length proteins annotated as putative LPMOs according to HMM profiles were confirmed by amino acid sequence comparison. The comparison results showed that although the amino acid sequences of the proteins were very different, they shared nine conserved amino acids, including two histidine and one phenylalanine that characterize the H1-Hx-Yz motif of the active site of bacterial LPMOs. Structural analysis of these proteins revealed that they are multidomain proteins with different functions. Prediction of the catalytic domain 3-D structure of these putative LPMOs using Alphafold2 showed that their spatial structures were very similar in shape, although their protein sequences were very different. The results of testing the activity of proteins GL0247266 and GL0183513 show that they are chitin-active LPMOs. Prediction of the 3-D structures of these two LPMOs using Alphafold2 showed that GL0247266 had five functional domains, while GL0183513 had four functional domains, two of which that were similar to the GbpA_2 and GbpA_3 domains of protein GbpA of Vibrio cholerae bacteria. The GbpA_2 - GbpA_3 complex was also detected in 11 other proteins. Based on the structural characteristics of functional domains, it is possible to hypothesize the role of chitin-active GbpA-like LPMOs in the relationship between fungal and bacterial communities coexisting on decomposing trees in primary forests.
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Affiliation(s)
- Nam-Hai Truong
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
- Graduate University of Science and Technology (GUST), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Thi-Thu-Hong Le
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
- Graduate University of Science and Technology (GUST), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Hong-Duong Nguyen
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | | | - Trong-Khoa Dao
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Thi-Minh-Nguyet Tran
- The Key Laboratory of Enzyme and Protein Technology (KLEPT), VNU University of Science, Hanoi, Vietnam
| | - Huyen-Linh Tran
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Dinh-Trong Nguyen
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Thi-Quy Nguyen
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Thi-Hong-Thao Phan
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Thi-Huyen Do
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
- Graduate University of Science and Technology (GUST), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Ngoc-Han Phan
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh, Vietnam
| | - Thi-Cam-Nhung Ngo
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh, Vietnam
| | - Van-Van Vu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh, Vietnam
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3
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Sulaeva I, Sto̷pamo FG, Melikhov I, Budischowsky D, Rahikainen JL, Borisova A, Marjamaa K, Kruus K, Eijsink VGH, Várnai A, Potthast A. Beyond the Surface: A Methodological Exploration of Enzyme Impact along the Cellulose Fiber Cross-Section. Biomacromolecules 2024; 25:3076-3086. [PMID: 38634234 PMCID: PMC11094719 DOI: 10.1021/acs.biomac.4c00152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/19/2024]
Abstract
Despite the wide range of analytical tools available for the characterization of cellulose, the in-depth characterization of inhomogeneous, layered cellulose fiber structures remains a challenge. When treating fibers or spinning man-made fibers, the question always arises as to whether the changes in the fiber structure affect only the surface or the entire fiber. Here, we developed an analysis tool based on the sequential limited dissolution of cellulose fiber layers. The method can reveal potential differences in fiber properties along the cross-sectional profile of natural or man-made cellulose fibers. In this analytical approach, carbonyl groups are labeled with a carbonyl selective fluorescence label (CCOA), after which thin fiber layers are sequentially dissolved with the solvent system DMAc/LiCl (9% w/v) and analyzed with size exclusion chromatography coupled with light scattering and fluorescence detection. The analysis of these fractions allowed for the recording of the changes in the chemical structure across the layers, resulting in a detailed cross-sectional profile of the different functionalities and molecular weight distributions. The method was optimized and tested in practice with LPMO (lytic polysaccharide monooxygenase)-treated cotton fibers, where it revealed the depth of fiber modification by the enzyme.
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Affiliation(s)
- Irina Sulaeva
- Core
Facility Analysis of Lignocellulosics (ALICE), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Strasse 24, A-3430 Tulln an der Donau, Austria
| | - Fredrik Gjerstad Sto̷pamo
- Faculty
of Chemistry, Biotechnology and Food Science, NMBU − Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Ivan Melikhov
- Institute
of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Strasse
24, A-3430 Tulln
an der Donau, Austria
| | - David Budischowsky
- Institute
of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Strasse
24, A-3430 Tulln
an der Donau, Austria
| | - Jenni L. Rahikainen
- Solutions
for Natural Resources and Environment, VTT
Technical Research Centre of Finland Ltd., Tietotie 2, FI-02044 Espoo, Finland
| | - Anna Borisova
- Solutions
for Natural Resources and Environment, VTT
Technical Research Centre of Finland Ltd., Tietotie 2, FI-02044 Espoo, Finland
| | - Kaisa Marjamaa
- Solutions
for Natural Resources and Environment, VTT
Technical Research Centre of Finland Ltd., Tietotie 2, FI-02044 Espoo, Finland
| | - Kristiina Kruus
- Solutions
for Natural Resources and Environment, VTT
Technical Research Centre of Finland Ltd., Tietotie 2, FI-02044 Espoo, Finland
- School
of Chemical Engineering, Aalto University, P.O. Box 16100, 00076 Espoo, Finland
| | - Vincent G. H. Eijsink
- Faculty
of Chemistry, Biotechnology and Food Science, NMBU − Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Anikó Várnai
- Faculty
of Chemistry, Biotechnology and Food Science, NMBU − Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Antje Potthast
- Institute
of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Strasse
24, A-3430 Tulln
an der Donau, Austria
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4
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Støpamo FG, Sulaeva I, Budischowsky D, Rahikainen J, Marjamaa K, Potthast A, Kruus K, Eijsink VGH, Várnai A. Oxidation of cellulose fibers using LPMOs with varying allomorphic substrate preferences, oxidative regioselectivities, and domain structures. Carbohydr Polym 2024; 330:121816. [PMID: 38368098 DOI: 10.1016/j.carbpol.2024.121816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 02/19/2024]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are excellent candidates for enzymatic functionalization of natural polysaccharides, such as cellulose or chitin, and are gaining relevance in the search for renewable biomaterials. Here, we assessed the cellulose fiber modification potential and catalytic performance of eleven cellulose-active fungal AA9-type LPMOs, including C1-, C4-, and C1/C4-oxidizing LPMOs with and without CBM1 carbohydrate-binding modules, on cellulosic substrates with different degrees of crystallinity and polymer chain arrangement, namely, Cellulose I, Cellulose II, and amorphous cellulose. The potential of LPMOs for cellulose fiber modification varied among the LPMOs and depended primarily on operational stability and substrate binding, and, to some extent, also on regioselectivity and domain structure. While all tested LPMOs were active on natural Cellulose I-type fibers, activity on the Cellulose II allomorph was almost exclusively detected for LPMOs containing a CBM1 and LPMOs with activity on soluble hemicelluloses and cello-oligosaccharides, for example NcAA9C from Neurospora crassa. The single-domain variant of NcAA9C oxidized the cellulose fibers to a higher extent than its CBM-containing natural variant and released less soluble products, indicating a more dispersed oxidation pattern without a CBM. Our findings reveal great functional variation among cellulose-active LPMOs, laying the groundwork for further LPMO-based cellulose engineering.
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Affiliation(s)
| | - Irina Sulaeva
- University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
| | - David Budischowsky
- University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
| | | | - Kaisa Marjamaa
- VTT Technical Research Centre of Finland, Espoo, Finland.
| | - Antje Potthast
- University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
| | - Kristiina Kruus
- VTT Technical Research Centre of Finland, Espoo, Finland; Aalto University, Espoo, Finland.
| | | | - Anikó Várnai
- Norwegian University of Life Sciences (NMBU), Ås, Norway.
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5
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Wieduwilt EK, Lo Leggio L, Hedegård ED. A frontier-orbital view of the initial steps of lytic polysaccharide monooxygenase reactions. Dalton Trans 2024; 53:5796-5807. [PMID: 38445349 DOI: 10.1039/d3dt04275h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper enzymes that oxidatively cleave the strong C-H bonds in recalcitrant polysaccharide substrates, thereby playing a crucial role in biomass degradation. Recently, LPMOs have also been shown to be important for several pathogens. It is well established that the Cu(II) resting state of LPMOs is inactive, and the electronic structure of the active site needs to be altered to transform the enzyme into an active form. Whether this transformation occurs due to substrate binding or due to a unique priming reduction has remained speculative. Starting from four different crystal structures of the LPMO LsAA9A with well-defined oxidation states, we use a frontier molecular orbital approach to elucidate the initial steps of the LPMO reaction. We give an explanation for the requirement of the unique priming reduction and analyse electronic structure changes upon substrate binding. We further investigate how the presence of the substrate could facilitate an electron transfer from the copper active site to an H2O2 co-substrate. Our findings could help to control experimental LPMO reactions.
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Affiliation(s)
- Erna Katharina Wieduwilt
- Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Erik Donovan Hedegård
- Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
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6
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Sulaeva I, Budischowsky D, Rahikainen J, Marjamaa K, Støpamo FG, Khaliliyan H, Melikhov I, Rosenau T, Kruus K, Várnai A, Eijsink VGH, Potthast A. A novel approach to analyze the impact of lytic polysaccharide monooxygenases (LPMOs) on cellulosic fibres. Carbohydr Polym 2024; 328:121696. [PMID: 38220335 DOI: 10.1016/j.carbpol.2023.121696] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/26/2023] [Accepted: 12/12/2023] [Indexed: 01/16/2024]
Abstract
Enzymatic treatment of cellulosic fibres is a green alternative to classical chemical modification. For many applications, mild procedures for cellulose alteration are sufficient, in which the fibre structure and, therefore, the mechanical performance of cellulosic fibres are preserved. Lytic polysaccharide monooxygenases (LPMOs) bear a great potential to become a green reagent for such targeted cellulose modifications. An obstacle for wide implementation of LPMOs in tailored cellulose chemistry is the lack of suitable techniques to precisely monitor the LPMO impact on the polymer. Soluble oxidized cello-oligomers can be quantified using chromatographic and mass-spectrometric techniques. A considerable portion of the oxidized sites, however, remain on the insoluble cellulose fibres, and their quantification is difficult. Here, we describe a method for the simultaneous quantification of oxidized sites on cellulose fibres and changes in their molar mass distribution after treatment with LPMOs. The method is based on quantitative, heterogeneous, carbonyl-selective labelling with a fluorescent label (CCOA) followed by cellulose dissolution and size-exclusion chromatography (SEC). Application of the method to reactions of seven different LPMOs with pure cellulose fibres revealed pronounced functional differences between the enzymes, showing that this CCOA/SEC/MALS method is a promising tool to better understand the catalytic action of LPMOs.
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Affiliation(s)
- Irina Sulaeva
- Core Facility "Analysis of Lignocellulosics" (ALICE), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Straße 24, A-3430 Tulln an der Donau, Austria
| | - David Budischowsky
- Institute of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Straße 24, A-3430 Tulln an der Donau, Austria
| | - Jenni Rahikainen
- Solutions for Natural Resources and Environment, VTT Technical Research Centre of Finland Ltd, Tietotie 2, FI-02044 Espoo, Finland
| | - Kaisa Marjamaa
- Solutions for Natural Resources and Environment, VTT Technical Research Centre of Finland Ltd, Tietotie 2, FI-02044 Espoo, Finland
| | - Fredrik Gjerstad Støpamo
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Hajar Khaliliyan
- Institute of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Straße 24, A-3430 Tulln an der Donau, Austria
| | - Ivan Melikhov
- Institute of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Straße 24, A-3430 Tulln an der Donau, Austria
| | - Thomas Rosenau
- Institute of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Straße 24, A-3430 Tulln an der Donau, Austria
| | - Kristiina Kruus
- Solutions for Natural Resources and Environment, VTT Technical Research Centre of Finland Ltd, Tietotie 2, FI-02044 Espoo, Finland; School of Chemical Engineering, Aalto University, P.O. Box 16100, Espoo 00076 AALTO, Finland
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Antje Potthast
- Institute of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz-Straße 24, A-3430 Tulln an der Donau, Austria.
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7
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Rajagopal BS, Yates N, Smith J, Paradisi A, Tétard-Jones C, Willats WGT, Marcus S, Knox JP, Firdaus-Raih M, Henrissat B, Davies GJ, Walton PH, Parkin A, Hemsworth GR. Structural dissection of two redox proteins from the shipworm symbiont Teredinibacter turnerae. IUCRJ 2024; 11:260-274. [PMID: 38446458 PMCID: PMC10916295 DOI: 10.1107/s2052252524001386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/12/2024] [Indexed: 03/07/2024]
Abstract
The discovery of lytic polysaccharide monooxygenases (LPMOs), a family of copper-dependent enzymes that play a major role in polysaccharide degradation, has revealed the importance of oxidoreductases in the biological utilization of biomass. In fungi, a range of redox proteins have been implicated as working in harness with LPMOs to bring about polysaccharide oxidation. In bacteria, less is known about the interplay between redox proteins and LPMOs, or how the interaction between the two contributes to polysaccharide degradation. We therefore set out to characterize two previously unstudied proteins from the shipworm symbiont Teredinibacter turnerae that were initially identified by the presence of carbohydrate binding domains appended to uncharacterized domains with probable redox functions. Here, X-ray crystal structures of several domains from these proteins are presented together with initial efforts to characterize their functions. The analysis suggests that the target proteins are unlikely to function as LPMO electron donors, raising new questions as to the potential redox functions that these large extracellular multi-haem-containing c-type cytochromes may perform in these bacteria.
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Affiliation(s)
- Badri S. Rajagopal
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Nick Yates
- Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Jake Smith
- Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | | | - Catherine Tétard-Jones
- School of Natural and Environmental Science, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - William G. T. Willats
- School of Natural and Environmental Science, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Susan Marcus
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - J. Paul Knox
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Mohd Firdaus-Raih
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Malaysia
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Aix-Marseille Université, Marseille, France
- INRA, USC 1408 AFMB, Marseille, France
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Gideon J. Davies
- Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Paul H. Walton
- Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Alison Parkin
- Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Glyn R. Hemsworth
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
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8
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Ma L, Wang M, Gao Y, Wu Y, Zhu C, An S, Tang S, She Q, Gao J, Meng X. Functional study of a lytic polysaccharide monooxygenase MsLPMO3 from Morchella sextelata in the oxidative degradation of cellulose. Enzyme Microb Technol 2024; 173:110376. [PMID: 38096655 DOI: 10.1016/j.enzmictec.2023.110376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 11/09/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) can improve the effectiveness with which agricultural waste is utilized. This study described the potent AA9 family protein MsLPMO3, derived from Morchella sextelata. It exhibited strong binding to phosphoric acid swollen cellulose (PASC), and had the considerable binding ability to Cu2+ with a Kd value of 2.70 μM by isothermal titration calorimetry (ITC). MsLPMO3 could also act on PASC at the C1 carbon via MALDI-TOF-MS results. Moreover, MsLPMO3 could boost the hydrolysis efficiency of corncob and wheat bran in combination with glycoside hydrolases. MsLPMO3 also exhibited strong oxidizing ability for 2,6-dimethoxyphenol (2,6-DMP), achieving the best Vmax value of 443.36 U·g-1 for pH 7.4 with a H2O2 concentration of 300 µM. The structure of MsLPMO3 was obtained using AlphaFold2, and the molecular docking results elucidated the specific interactions and key residues involved in the recognition process between MsLPMO3 and cellulose. Altogether, this study expands the knowledge of AA9 family proteins in cellulose degradation, providing valuable insights into the mechanisms of synergistic degradation of lignocellulose with cellulases.
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Affiliation(s)
- Lei Ma
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Mengmeng Wang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, People's Republic of China
| | - Ya Gao
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Yinghong Wu
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Chaoqiang Zhu
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Shuyu An
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Siyu Tang
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, People's Republic of China
| | - Qiusheng She
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Jianmin Gao
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Xiaohui Meng
- Department of Agronomy and Horticulture, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, People's Republic of China.
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9
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Munzone A, Eijsink VGH, Berrin JG, Bissaro B. Expanding the catalytic landscape of metalloenzymes with lytic polysaccharide monooxygenases. Nat Rev Chem 2024; 8:106-119. [PMID: 38200220 DOI: 10.1038/s41570-023-00565-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2023] [Indexed: 01/12/2024]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) have an essential role in global carbon cycle, industrial biomass processing and microbial pathogenicity by catalysing the oxidative cleavage of recalcitrant polysaccharides. Despite initially being considered monooxygenases, experimental and theoretical studies show that LPMOs are essentially peroxygenases, using a single copper ion and H2O2 for C-H bond oxygenation. Here, we examine LPMO catalysis, emphasizing key studies that have shaped our comprehension of their function, and address side and competing reactions that have partially obscured our understanding. Then, we compare this novel copper-peroxygenase reaction with reactions catalysed by haem iron enzymes, highlighting the different chemistries at play. We conclude by addressing some open questions surrounding LPMO catalysis, including the importance of peroxygenase and monooxygenase reactions in biological contexts, how LPMOs modulate copper site reactivity and potential protective mechanisms against oxidative damage.
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Affiliation(s)
- Alessia Munzone
- UMR1163 Biodiversité et Biotechnologie Fongiques, INRAE, Aix Marseille University, Marseille, France
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology, and Food Science, The Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Jean-Guy Berrin
- UMR1163 Biodiversité et Biotechnologie Fongiques, INRAE, Aix Marseille University, Marseille, France
| | - Bastien Bissaro
- UMR1163 Biodiversité et Biotechnologie Fongiques, INRAE, Aix Marseille University, Marseille, France.
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10
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Chorozian K, Karnaouri A, Georgaki-Kondyli N, Karantonis A, Topakas E. Assessing the role of redox partners in TthLPMO9G and its mutants: focus on H 2O 2 production and interaction with cellulose. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:19. [PMID: 38303072 PMCID: PMC10835826 DOI: 10.1186/s13068-024-02463-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/18/2024] [Indexed: 02/03/2024]
Abstract
BACKGROUND The field of enzymology has been profoundly transformed by the discovery of lytic polysaccharide monooxygenases (LPMOs). LPMOs hold a unique role in the natural breakdown of recalcitrant polymers like cellulose and chitin. They are characterized by a "histidine brace" in their active site, known to operate via an O2/H2O2 mechanism and require an electron source for catalytic activity. Although significant research has been conducted in the field, the relationship between these enzymes, their electron donors, and H2O2 production remains complex and multifaceted. RESULTS This study examines TthLPMO9G activity, focusing on its interactions with various electron donors, H2O2, and cellulose substrate interactions. Moreover, the introduction of catalase effectively eliminates H2O2 interference, enabling an accurate evaluation of each donor's efficacy based on electron delivery to the LPMO active site. The introduction of catalase enhances TthLPMO9G's catalytic efficiency, leading to increased cellulose oxidation. The current study provides deeper insights into specific point mutations, illuminating the crucial role of the second coordination sphere histidine at position 140. Significantly, the H140A mutation not only impacted the enzyme's ability to oxidize cellulose, but also altered its interaction with H2O2. This change was manifested in the observed decrease in both oxidase and peroxidase activities. Furthermore, the S28A substitution, selected for potential engagement within the His1-electron donor-cellulose interaction triad, displayed electron donor-dependent alterations in cellulose product patterns. CONCLUSION The interaction of an LPMO with H2O2, electron donors, and cellulose substrate, alongside the impact of catalase, offers deep insights into the intricate interactions occurring at the molecular level within the enzyme. Through rational alterations and substitutions that affect both the first and second coordination spheres of the active site, this study illuminates the enzyme's function. These insights enhance our understanding of the enzyme's mechanisms, providing valuable guidance for future research and potential applications in enzymology and biochemistry.
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Affiliation(s)
- Koar Chorozian
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Athens, Greece
| | - Anthi Karnaouri
- Laboratory of General and Agricultural Microbiology, Department of Crop Science, Agricultural University of Athens, 11855, Athens, Greece
| | - Nefeli Georgaki-Kondyli
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Athens, Greece
| | - Antonis Karantonis
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Athens, Greece
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Athens, Greece.
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11
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Gao W, Li T, Zhou H, Ju J, Yin H. Carbohydrate-binding modules enhance H 2O 2 tolerance by promoting lytic polysaccharide monooxygenase active site H 2O 2 consumption. J Biol Chem 2024; 300:105573. [PMID: 38122901 PMCID: PMC10825053 DOI: 10.1016/j.jbc.2023.105573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/26/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) oxidatively depolymerize recalcitrant polysaccharides, which is important for biomass conversion. The catalytic domains of many LPMOs are linked to carbohydrate-binding modules (CBMs) through flexible linkers, but the function of these CBMs in LPMO catalysis is not well understood. In this study, we utilized MtLPMO9L and MtLPMO9G derived from Myceliophthora thermophila to investigate the impact of CBMs on LPMO activity, with particular emphasis on their influence on H2O2 tolerance. Using truncated forms of MtLPMO9G generated by removing the CBM, we found reduced substrate binding affinity and enzymatic activity. Conversely, when the CBM was fused to the C terminus of the single-domain MtLPMO9L to create MtLPMO9L-CBM, we observed a substantial improvement in substrate binding affinity, enzymatic activity, and notably, H2O2 tolerance. Furthermore, molecular dynamics simulations confirmed that the CBM fusion enhances the proximity of the active site to the substrate, thereby promoting multilocal cleavage and impacting the exposure of the copper active site to H2O2. Importantly, the fusion of CBM resulted in more efficient consumption of H2O2 by LPMO, leading to improved enzymatic activity and reduced auto-oxidative damage of the copper active center.
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Affiliation(s)
- Wa Gao
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China; University of Chinese Academy of Sciences, Beijing, China
| | - Tang Li
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Haichuan Zhou
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Jiu Ju
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Heng Yin
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China; University of Chinese Academy of Sciences, Beijing, China.
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12
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Østby H, Christensen IA, Hennum K, Várnai A, Buchinger E, Grandal S, Courtade G, Hegnar OA, Aachmann FL, Eijsink VGH. Functional characterization of a lytic polysaccharide monooxygenase from Schizophyllum commune that degrades non-crystalline substrates. Sci Rep 2023; 13:17373. [PMID: 37833388 PMCID: PMC10575960 DOI: 10.1038/s41598-023-44278-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are mono-copper enzymes that use O2 or H2O2 to oxidatively cleave glycosidic bonds. LPMOs are prevalent in nature, and the functional variation among these enzymes is a topic of great interest. We present the functional characterization of one of the 22 putative AA9-type LPMOs from the fungus Schizophyllum commune, ScLPMO9A. The enzyme, expressed in Escherichia coli, showed C4-oxidative cleavage of amorphous cellulose and soluble cello-oligosaccharides. Activity on xyloglucan, mixed-linkage β-glucan, and glucomannan was also observed, and product profiles differed compared to the well-studied C4-oxidizing NcLPMO9C from Neurospora crassa. While NcLPMO9C is also active on more crystalline forms of cellulose, ScLPMO9A is not. Differences between the two enzymes were also revealed by nuclear magnetic resonance (NMR) titration studies showing that, in contrast to NcLPMO9C, ScLPMO9A has higher affinity for linear substrates compared to branched substrates. Studies of H2O2-fueled degradation of amorphous cellulose showed that ScLPMO9A catalyzes a fast and specific peroxygenase reaction that is at least two orders of magnitude faster than the apparent monooxygenase reaction. Together, these results show that ScLPMO9A is an efficient LPMO with a broad substrate range, which, rather than acting on cellulose, has evolved to act on amorphous and soluble glucans.
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Affiliation(s)
- Heidi Østby
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Idd A Christensen
- Norwegian Biopolymer Laboratory (NOBIPOL), Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands Vei 6/8, 7491, Trondheim, Norway
| | - Karen Hennum
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Edith Buchinger
- Norwegian Biopolymer Laboratory (NOBIPOL), Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands Vei 6/8, 7491, Trondheim, Norway
| | - Siri Grandal
- Norwegian Biopolymer Laboratory (NOBIPOL), Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands Vei 6/8, 7491, Trondheim, Norway
| | - Gaston Courtade
- Norwegian Biopolymer Laboratory (NOBIPOL), Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands Vei 6/8, 7491, Trondheim, Norway
| | - Olav A Hegnar
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Finn L Aachmann
- Norwegian Biopolymer Laboratory (NOBIPOL), Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands Vei 6/8, 7491, Trondheim, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway.
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13
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de Oliveira Gorgulho Silva C, Vuillemin M, Kabel MA, van Berkel WJH, Meyer AS, Agger JW. Polyphenol Oxidase Products Are Priming Agents for LPMO Peroxygenase Activity. CHEMSUSCHEM 2023; 16:e202300559. [PMID: 37278305 DOI: 10.1002/cssc.202300559] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/26/2023] [Accepted: 06/05/2023] [Indexed: 06/07/2023]
Abstract
Polyphenol oxidases catalyze the hydroxylation of monophenols to diphenols, which are reducing agents for lytic polysaccharide monooxygenases (LPMOs) in their degradation of cellulose. In particular, the polyphenol oxidase MtPPO7 from Myceliophthora thermophila converts lignocellulose-derived monophenols, and under the new perspective of the peroxygenase reaction catalyzed by LPMOs, we aim to differentiate the role of the catalytic products of MtPPO7 in priming and fueling of LPMO activity. Exemplified by the activity of MtPPO7 towards guaiacol and by using the benchmark LPMO NcAA9C from Neurospora crassa we show that MtPPO7 catalytic products provide the initial electron for the reduction of Cu(II) to Cu(I) but cannot provide the required reducing power for continuous fueling of the LPMO. The priming reaction is shown to occur with catalytic amounts of MtPPO7 products and those compounds do not generate substantial amounts of H2 O2 in situ to fuel the LPMO peroxygenase activity. Reducing agents with a low propensity to generate H2 O2 can provide the means for controlling the LPMO catalysis through exogenous H2 O2 and thereby minimize any enzyme inactivation.
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Affiliation(s)
| | - Marlene Vuillemin
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800, Kgs Lyngby, Denmark
| | - Mirjam A Kabel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - Anne S Meyer
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800, Kgs Lyngby, Denmark
| | - Jane W Agger
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800, Kgs Lyngby, Denmark
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14
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Mathieu Y, Raji O, Bellemare A, Di Falco M, Nguyen TTM, Viborg AH, Tsang A, Master E, Brumer H. Functional characterization of fungal lytic polysaccharide monooxygenases for cellulose surface oxidation. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:132. [PMID: 37679837 PMCID: PMC10486138 DOI: 10.1186/s13068-023-02383-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/14/2023] [Indexed: 09/09/2023]
Abstract
BACKGROUND Microbial lytic polysaccharide monooxygenases (LPMOs) cleave diverse biomass polysaccharides, including cellulose and hemicelluloses, by initial oxidation at C1 or C4 of glycan chains. Within the Carbohydrate-Active Enzymes (CAZy) classification, Auxiliary Activity Family 9 (AA9) comprises the first and largest group of fungal LPMOs, which are often also found in tandem with non-catalytic carbohydrate-binding modules (CBMs). LPMOs originally attracted attention for their ability to potentiate complete biomass deconstruction to monosaccharides. More recently, LPMOs have been applied for selective surface modification of insoluble cellulose and chitin. RESULTS To further explore the catalytic diversity of AA9 LPMOs, over 17,000 sequences were extracted from public databases, filtered, and used to construct a sequence similarity network (SSN) comprising 33 phylogenetically supported clusters. From these, 32 targets were produced successfully in the industrial filamentous fungus Aspergillus niger, 25 of which produced detectable LPMO activity. Detailed biochemical characterization of the eight most highly produced targets revealed individual C1, C4, and mixed C1/C4 regiospecificities of cellulose surface oxidation, different redox co-substrate preferences, and CBM targeting effects. Specifically, the presence of a CBM correlated with increased formation of soluble oxidized products and a more localized pattern of surface oxidation, as indicated by carbonyl-specific fluorescent labeling. On the other hand, LPMOs without native CBMs were associated with minimal release of soluble products and comparatively dispersed oxidation pattern. CONCLUSIONS This work provides insight into the structural and functional diversity of LPMOs, and highlights the need for further detailed characterization of individual enzymes to identify those best suited for cellulose saccharification versus surface functionalization toward biomaterials applications.
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Affiliation(s)
- Yann Mathieu
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
- BioProducts Institute, University of British Columbia, 2385 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Olanrewaju Raji
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Annie Bellemare
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Marcos Di Falco
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Thi Truc Minh Nguyen
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Alexander Holm Viborg
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Adrian Tsang
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Emma Master
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada.
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland.
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada.
- BioProducts Institute, University of British Columbia, 2385 East Mall, Vancouver, BC, V6T 1Z4, Canada.
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada.
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
- Department of Botany, University of British Columbia, 3200 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.
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15
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Kuusk S, Eijsink VGH, Väljamäe P. The "life-span" of lytic polysaccharide monooxygenases (LPMOs) correlates to the number of turnovers in the reductant peroxidase reaction. J Biol Chem 2023; 299:105094. [PMID: 37507015 PMCID: PMC10458328 DOI: 10.1016/j.jbc.2023.105094] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/02/2023] [Accepted: 07/22/2023] [Indexed: 07/30/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are monocopper enzymes that degrade the insoluble crystalline polysaccharides cellulose and chitin. Besides the H2O2 cosubstrate, the cleavage of glycosidic bonds by LPMOs depends on the presence of a reductant needed to bring the enzyme into its reduced, catalytically active Cu(I) state. Reduced LPMOs that are not bound to substrate catalyze reductant peroxidase reactions, which may lead to oxidative damage and irreversible inactivation of the enzyme. However, the kinetics of this reaction remain largely unknown, as do possible variations between LPMOs belonging to different families. Here, we describe the kinetic characterization of two fungal family AA9 LPMOs, TrAA9A of Trichoderma reesei and NcAA9C of Neurospora crassa, and two bacterial AA10 LPMOs, ScAA10C of Streptomyces coelicolor and SmAA10A of Serratia marcescens. We found peroxidation of ascorbic acid and methyl-hydroquinone resulted in the same probability of LPMO inactivation (pi), suggesting that inactivation is independent of the nature of the reductant. We showed the fungal enzymes were clearly more resistant toward inactivation, having pi values of less than 0.01, whereas the pi for SmAA10A was an order of magnitude higher. However, the fungal enzymes also showed higher catalytic efficiencies (kcat/KM(H2O2)) for the reductant peroxidase reaction. This inverse linear correlation between the kcat/KM(H2O2) and pi suggests that, although having different life spans in terms of the number of turnovers in the reductant peroxidase reaction, LPMOs that are not bound to substrates have similar half-lives. These findings have not only potential biological but also industrial implications.
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Affiliation(s)
- Silja Kuusk
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Sciences, Ås, Norway
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
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16
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Hall K, Joseph C, Ayuso-Fernández I, Tamhankar A, Rieder L, Skaali R, Golten O, Neese F, Røhr ÅK, Jannuzzi SAV, DeBeer S, Eijsink VGH, Sørlie M. A Conserved Second Sphere Residue Tunes Copper Site Reactivity in Lytic Polysaccharide Monooxygenases. J Am Chem Soc 2023; 145:18888-18903. [PMID: 37584157 PMCID: PMC10472438 DOI: 10.1021/jacs.3c05342] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Indexed: 08/17/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are powerful monocopper enzymes that can activate strong C-H bonds through a mechanism that remains largely unknown. Herein, we investigated the role of a conserved glutamine/glutamate in the second coordination sphere. Mutation of the Gln in NcAA9C to Glu, Asp, or Asn showed that the nature and distance of the headgroup to the copper fine-tune LPMO functionality and copper reactivity. The presence of Glu or Asp close to the copper lowered the reduction potential and decreased the ratio between the reduction and reoxidation rates by up to 500-fold. All mutants showed increased enzyme inactivation, likely due to changes in the confinement of radical intermediates, and displayed changes in a protective hole-hopping pathway. Electron paramagnetic resonance (EPR) and X-ray absorption spectroscopic (XAS) studies gave virtually identical results for all NcAA9C variants, showing that the mutations do not directly perturb the Cu(II) ligand field. DFT calculations indicated that the higher experimental reoxidation rate observed for the Glu mutant could be reconciled if this residue is protonated. Further, for the glutamic acid form, we identified a Cu(III)-hydroxide species formed in a single step on the H2O2 splitting path. This is in contrast to the Cu(II)-hydroxide and hydroxyl intermediates, which are predicted for the WT and the unprotonated glutamate variant. These results show that this second sphere residue is a crucial determinant of the catalytic functioning of the copper-binding histidine brace and provide insights that may help in understanding LPMOs and LPMO-inspired synthetic catalysts.
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Affiliation(s)
- Kelsi
R. Hall
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Chris Joseph
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Iván Ayuso-Fernández
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Ashish Tamhankar
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Lukas Rieder
- Institute
for Molecular Biotechnology, Graz University
of Technology, 8010, Graz, Austria
| | - Rannei Skaali
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Ole Golten
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Åsmund K. Røhr
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Sergio A. V. Jannuzzi
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Vincent G. H. Eijsink
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Morten Sørlie
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
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17
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Gonçalves AL, Cunha PM, da Silva Lima A, Dos Santos JC, Segato F. Production of recombinant lytic polysaccharide monooxygenases and evaluation effect of its addition into Aspergillus fumigatus var. niveus cocktail for sugarcane bagasse saccharification. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140919. [PMID: 37164048 DOI: 10.1016/j.bbapap.2023.140919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/01/2023] [Accepted: 05/03/2023] [Indexed: 05/12/2023]
Abstract
Lignocellulosic biomass is a promising alternative for producing biofuels, despite its recalcitrant nature. There are microorganisms in nature capable of efficiently degrade biomass, such as the filamentous fungi. Among them, Aspergillus fumigatus var. niveus (AFUMN) has a wide variety of carbohydrate-active enzymes (CAZymes), especially hydrolases, but a low number of oxidative enzymes in its genome. To confirm the enzymatic profile of this fungus, this study analyzed the secretome of AFUMN cultured in sugarcane bagasse as the sole carbon source. As expected, the secretome showed a predominance of hydrolytic enzymes compared to oxidative activity. However, it is known that hydrolytic enzymes act in synergy with oxidative proteins to efficiently degrade cellulose polymer, such as the Lytic Polysaccharide Monooxygenases (LPMOs). Thus, three LPMOs from the fungus Thermothelomyces thermophilus (TtLPMO9D, TtLPMO9H, and TtLPMO9O) were selected, heterologous expressed in Aspergillus nidulans, purified, and used to supplement the AFUMN secretome to evaluate their effect on the saccharification of sugarcane bagasse. The saccharification assay was carried out using different concentrations of AFUMN secretome supplemented with recombinant T. thermophilus LPMOs, as well as ascorbic acid as reducing agent for oxidative enzymes. Through a statistic design created by Design-Expert software, we were able to analyze a possible cooperative effect between these components. The results indicated that, in general, the addition of TtLPMO9D and ascorbic acid did not favor the conversion process in this study, while TtLPMO9O had a highly significant cooperative effect in bagasse saccharification compared to the control using only AFUMN secretome.
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Affiliation(s)
- Aline Larissa Gonçalves
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Paula Macedo Cunha
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Awana da Silva Lima
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Júlio César Dos Santos
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Fernando Segato
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil.
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18
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Liu Y, Ma W, Fang X. The Role of the Residue at Position 2 in the Catalytic Activity of AA9 Lytic Polysaccharide Monooxygenases. Int J Mol Sci 2023; 24:ijms24098300. [PMID: 37176008 PMCID: PMC10179388 DOI: 10.3390/ijms24098300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/18/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
AA9 lytic polysaccharide monooxygenases (LPMOs) are copper-dependent metalloenzymes that play a major role in cellulose degradation and plant infection. Understanding the AA9 LPMO mechanism would facilitate the improvement of plant pathogen control and the industrial application of LPMOs. Herein, via point mutation, we investigated the role of glycine 2 residue in cellulose degradation by Thermoascus aurantiacus AA9 LPMOs (TaAA9). A computational simulation showed that increasing the steric properties of this residue by replacing glycine with threonine or tyrosine altered the H-bonding network of the copper center and copper coordination geometry, decreased the surface charge of the catalytic center, weakened the TaAA9-substrate interaction, and enhanced TaAA9-product binding. Compared with wild-type TaAA9, G2T-TaAA9 and G2Y-TaAA9 variants showed attenuated copper affinity, reduced oxidative product diversity and decreased substrate Avicel binding, as determined using ITC, MALDI-TOF/TOF MS and cellulose binding analyses, respectively. Consistently, the enzymatic activity and synergy with cellulase of the G2T-TaAA9 and G2Y-TaAA9 variants were lower than those of TaAA9. Hence, the investigated residue crucially affects the catalytic activity of AA9 LPMOs, and we propose that the electropositivity of copper may correlate with AA9 LPMO activity. Thus, the relationship among the amino acid at position 2, surface charge and catalytic activity may facilitate an understanding of the proteins in AA9 LPMOs.
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Affiliation(s)
- Yucui Liu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, China
| | - Wei Ma
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, China
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19
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The interplay between lytic polysaccharide monooxygenases and glycoside hydrolases. Essays Biochem 2023; 67:551-559. [PMID: 36876880 DOI: 10.1042/ebc20220156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 03/07/2023]
Abstract
In nature, enzymatic degradation of recalcitrant polysaccharides such as chitin and cellulose takes place by a synergistic interaction between glycoside hydrolases (GHs) and lytic polysaccharide monooxygenases (LPMOs). The two different families of carbohydrate-active enzymes use two different mechanisms when breaking glycosidic bonds between sugar moieties. GHs employ a hydrolytic activity and LPMOs are oxidative. Consequently, the topologies of the active sites differ dramatically. GHs have tunnels or clefts lined with a sheet of aromatic amino acid residues accommodating single polymer chains being threaded into the active site. LPMOs are adapted to bind to the flat crystalline surfaces of chitin and cellulose. It is believed that the LPMO oxidative mechanism provides new chain ends that the GHs can attach to and degrade, often in a processive manner. Indeed, there are many reports of synergies as well as rate enhancements when LPMOs are applied in concert with GHs. Still, these enhancements vary in magnitude with respect to the nature of the GH and the LPMO. Moreover, impediment of GH catalysis is also observed. In the present review, we discuss central works where the interplay between LPMOs and GHs has been studied and comment on future challenges to be addressed to fully use the potential of this interplay to improve enzymatic polysaccharide degradation.
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20
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Martinez-D’Alto A, Yan X, Detomasi TC, Sayler RI, Thomas WC, Talbot NJ, Marletta MA. Characterization of a unique polysaccharide monooxygenase from the plant pathogen Magnaporthe oryzae. Proc Natl Acad Sci U S A 2023; 120:e2215426120. [PMID: 36791100 PMCID: PMC9974505 DOI: 10.1073/pnas.2215426120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 01/12/2023] [Indexed: 02/16/2023] Open
Abstract
Blast disease in cereal plants is caused by the fungus Magnaporthe oryzae and accounts for a significant loss in food crops. At the outset of infection, expression of a putative polysaccharide monooxygenase (MoPMO9A) is increased. MoPMO9A contains a catalytic domain predicted to act on cellulose and a carbohydrate-binding domain that binds chitin. A sequence similarity network of the MoPMO9A family AA9 showed that 220 of the 223 sequences in the MoPMO9A-containing cluster of sequences have a conserved unannotated region with no assigned function. Expression and purification of the full length and two MoPMO9A truncations, one containing the catalytic domain and the domain of unknown function (DUF) and one with only the catalytic domain, were carried out. In contrast to other AA9 polysaccharide monooxygenases (PMOs), MoPMO9A is not active on cellulose but showed activity on cereal-derived mixed (1→3, 1→4)-β-D-glucans (MBG). Moreover, the DUF is required for activity. MoPMO9A exhibits activity consistent with C4 oxidation of the polysaccharide and can utilize either oxygen or hydrogen peroxide as a cosubstrate. It contains a predicted 3-dimensional fold characteristic of other PMOs. The DUF is predicted to form a coiled-coil with six absolutely conserved cysteines acting as a zipper between the two α-helices. MoPMO9A substrate specificity and domain architecture are different from previously characterized AA9 PMOs. The results, including a gene ontology analysis, support a role for MoPMO9A in MBG degradation during plant infection. Consistent with this analysis, deletion of MoPMO9A results in reduced pathogenicity.
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Affiliation(s)
| | - Xia Yan
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, NorwichNR4 7UH, UK
| | - Tyler C. Detomasi
- Department of Chemistry, University of California, Berkeley, CA94720
| | - Richard I. Sayler
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA94720
| | - William C. Thomas
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA94720
| | - Nicholas J. Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, NorwichNR4 7UH, UK
| | - Michael A. Marletta
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA94720
- Department of Chemistry, University of California, Berkeley, CA94720
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
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21
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Hagemann MM, Hedegård ED. Molecular Mechanism of Substrate Oxidation in Lytic Polysaccharide Monooxygenases: Insight from Theoretical Investigations. Chemistry 2023; 29:e202202379. [PMID: 36207279 PMCID: PMC10107554 DOI: 10.1002/chem.202202379] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Indexed: 12/12/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper enzymes that today comprise a large enzyme superfamily, grouped into the distinct members AA9-AA17 (with AA12 exempted). The LPMOs have the potential to facilitate the upcycling of biomass waste products by boosting the breakdown of cellulose and other recalcitrant polysaccharides. The cellulose biopolymer is the main component of biomass waste and thus comprises a large, unexploited resource. The LPMOs work through a catalytic, oxidative reaction whose mechanism is still controversial. For instance, the nature of the intermediate performing the oxidative reaction is an open question, and the same holds for the employed co-substrate. Here we review theoretical investigations addressing these questions. The applied theoretical methods are usually based on quantum mechanics (QM), often combined with molecular mechanics (QM/MM). We discuss advantages and disadvantages of the employed theoretical methods and comment on the interplay between theoretical and experimental results.
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Affiliation(s)
- Marlisa M Hagemann
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230, Odense, Denmark
| | - Erik D Hedegård
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230, Odense, Denmark
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22
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Constantinescu-Aruxandei D, Oancea F. Closing the Nutrient Loop-The New Approaches to Recovering Biomass Minerals during the Biorefinery Processes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:2096. [PMID: 36767462 PMCID: PMC9915181 DOI: 10.3390/ijerph20032096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
The recovery of plant mineral nutrients from the bio-based value chains is essential for a sustainable, circular bioeconomy, wherein resources are (re)used sustainably. The widest used approach is to recover plant nutrients on the last stage of biomass utilization processes-e.g., from ash, wastewater, or anaerobic digestate. The best approach is to recover mineral nutrients from the initial stages of biomass biorefinery, especially during biomass pre-treatments. Our paper aims to evaluate the nutrient recovery solutions from a trans-sectorial perspective, including biomass processing and the agricultural use of recovered nutrients. Several solutions integrated with the biomass pre-treatment stage, such as leaching/bioleaching, recovery from pre-treatment neoteric solvents, ionic liquids (ILs), and deep eutectic solvents (DESs) or integrated with hydrothermal treatments are discussed. Reducing mineral contents on silicon, phosphorus, and nitrogen biomass before the core biorefinery processes improves processability and yield and reduces corrosion and fouling effects. The recovered minerals are used as bio-based fertilizers or as silica-based plant biostimulants, with economic and environmental benefits.
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23
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Tong X, He Z, Zheng L, Pande H, Ni Y. Enzymatic treatment processes for the production of cellulose nanomaterials: A review. Carbohydr Polym 2023; 299:120199. [PMID: 36876810 DOI: 10.1016/j.carbpol.2022.120199] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 11/09/2022]
Abstract
Cellulose nanomaterials have attracted much attention in recent years because of their unique properties. Commercial or semi-commercial production of nanocellulose has been reported in recent years. Mechanical treatments for nanocellulose production are viable but highly energy-intensive. Chemical processes are well reported; however, these chemical processes are not only costly, but also cause environmental concerns and end-use related challenges. This review summarizes recent researches on enzymatic treatment of cellulose fibers for the production of cellulose nanomaterials, with focus on novel enzymatic processes with xylanase and lytic polysaccharide monooxygenases (LPMO) to enhance the efficacy of cellulase. Different enzymes are discussed, including endoglucanase, exoglucanase and xylanase, as well as LPMO, with emphasis on the accessibility and hydrolytic specificity of LPMO enzymes to cellulose fiber structures. LPMO acts in a synergistic way with cellulase to cause significant physical and chemical changes to the cellulose fiber cell-wall structures, which facilitate the nano-fibrillation of the fibers.
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Affiliation(s)
- Xin Tong
- Department of Chemical Engineering, Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, NB E3B5A3, Canada; Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou 310023, PR China
| | - Zhibin He
- Department of Chemical Engineering, Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, NB E3B5A3, Canada.
| | - Linqiang Zheng
- Department of Chemical Engineering, Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, NB E3B5A3, Canada
| | - Harshad Pande
- Domtar Corporation, 395 Blvd Maisonneuve West, Montreal, PQ H3A 1L6, Canada
| | - Yonghao Ni
- Department of Chemical Engineering, Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, NB E3B5A3, Canada
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Abstract
Lytic polysaccharide monooxygenases (LPMOs) are unique redox enzymes capable of disrupting the crystalline surfaces of industry-relevant recalcitrant polysaccharides, such as chitin and cellulose. Historically, LPMOs were thought to be slow enzymes relying on O2 as the co-substrate, but it is now clear that these enzymes prefer H2O2, allowing for fast depolymerization of polysaccharides through a peroxygenase reaction. Thus, quantifying H2O2 in LPMO reaction set-ups is of a great interest. The horseradish peroxidase (HRP)/Amplex Red (AR) assay is one of the most popular and accessible tools for measuring hydrogen peroxide. This assay has been used in various types of biological and biochemical studies, including LPMO research, but suffers from pitfalls that need to be accounted for. In this Chapter, we discuss this method and its use for assessing the often rate-limiting in situ formation of H2O2 in LPMO reactions. We show that, after accounting for multiple potential side reactions, quantitative data on H2O2 production obtained with the HRP/Amplex Red assay provide useful clues for understanding the catalytic activity of LPMOs, including the impact of reductants and transition metal ions.
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Affiliation(s)
- Anton A Stepnov
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway.
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25
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On the impact of carbohydrate-binding modules (CBMs) in lytic polysaccharide monooxygenases (LPMOs). Essays Biochem 2022; 67:561-574. [PMID: 36504118 PMCID: PMC10154629 DOI: 10.1042/ebc20220162] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 12/14/2022]
Abstract
Abstract
Lytic polysaccharide monooxygenases (LPMOs) have revolutionized our understanding of how enzymes degrade insoluble polysaccharides. Compared with the substantial knowledge developed on the structure and mode of action of the catalytic LPMO domains, the (multi)modularity of LPMOs has received less attention. The presence of other domains, in particular carbohydrate-binding modules (CBMs), tethered to LPMOs has profound implications for the catalytic performance of the full-length enzymes. In the last few years, studies on LPMO modularity have led to advancements in elucidating how CBMs, other domains, and linker regions influence LPMO structure and function. This mini review summarizes recent literature, with particular focus on comparative truncation studies, to provide an overview of the diversity in LPMO modularity and the functional implications of this diversity.
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Yu W, Yu J, Li D. Analysis of lytic polysaccharide monooxygenase activity in thermophilic fungi by high-performance liquid chromatography–refractive index detector. Front Microbiol 2022; 13:1063025. [DOI: 10.3389/fmicb.2022.1063025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/07/2022] [Indexed: 11/23/2022] Open
Abstract
IntroductionMost current methods for analysing the activity of LPMO are based on the quantification of H2O2, a side product of LPMO; however, these methods cannot assay the LPMO activity of thermophilic fungi because of the low thermostability of H2O2. Therefore, we present a high-performance liquid chromatography–refractive index detector (HPLC-RID) method to assay the LPMO activity of the thermophilic fungus Thermoascus aurantiacus.ResultsAccording to the established method, the specific activities of nTaAA9A C1 and C4 oxidation were successfully analysed and were 0.646 and 0.574 U/mg, respectively. By using these methods, we analyzed the C1 and C4 oxidation activities of the recombinant TaAA9A (rTaAA9A) and mutated rTaAA9A (Y24A, F43A, and Y212A) expressed in Pichia pastoris. The specific activities of rTaAA9A C1 and C4 oxidation were 0.155 and 0.153 U/mg, respectively. The specific activities of Y24A, F43A, and Y212A C1 and C4 oxidation were 0.128 and 0.125 U/mg, 0.194 and 0.192 U/mg, and 0.097 and 0.146 U/mg, respectively.DiscussionIn conclusion, the method can assay the LPMO activity of thermophilic fungi and directly target C1 and C4 oxidation, which provides an effective activity assay method for LPMOs of thermophilic fungi.
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27
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Ngo ST, Phan HN, Luu CX, Le CN, Ho GT, Ngo NTC, Le LQ, Mai BK, Phung HTT, Nguyen HD, Vu KB, Vu VV. Distal Hydrophobic Loop Modulates the Copper Active Site and Reaction of AA13 Polysaccharide Monooxygenases. J Phys Chem B 2022; 126:7567-7578. [PMID: 36137238 DOI: 10.1021/acs.jpcb.2c04215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polysaccharide monooxygenases (PMOs) use a type-2 copper center to activate O2 for the selective hydroxylation of one of the two C-H bonds of glycosidic linkages. Our electron paramagnetic resonance (EPR) analysis and molecular dynamics (MD) simulations suggest the unprecedented dynamic roles of the loop containing the residue G89 (G89 loop) on the active site structure and reaction cycle of starch-active PMOs (AA13 PMOs). In the Cu(II) state, the G89 loop could switch between an "open" and "closed" conformation, which is associated with the binding and dissociation of an aqueous ligand in the distal site, respectively. The conformation of the G89 loop influences the positioning of the copper center on the preferred substrate of AA13 PMOs. The dissociation of the distal ligand results in the bending of the T-shaped core of the Cu(II) active site, which could help facilitate its reduction to the active Cu(I) state. In the Cu(I) state, the G89 loop is in the "closed" conformation with a confined copper center, which could allow for efficient O2 binding. In addition, the G89 loop remains in the "closed" conformation in the Cu(II)-superoxo intermediate, which could prevent off-pathway superoxide release via exchange with the distal aqueous ligand. Finally, at the end of the reaction cycle, aqueous ligand binding to the distal site could switch the G89 loop to the "open" conformation and facilitate product release.
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Affiliation(s)
- Son Tung Ngo
- Laboratory of Theoretical and Computational Biophysics, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam.,Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam
| | - Han N Phan
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Cuong X Luu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Chinh N Le
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Giap T Ho
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Nhung T C Ngo
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Loan Q Le
- Institute of Tropical Biology, Vietnam Academy of Science and Technology, 9/621 Hanoi Highway, Thu Duc District, Ho Chi Minh City 700000, Vietnam
| | - Binh Khanh Mai
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden
| | - Huong T T Phung
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Hoang-Dung Nguyen
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam.,Institute of Tropical Biology, Vietnam Academy of Science and Technology, 9/621 Hanoi Highway, Thu Duc District, Ho Chi Minh City 700000, Vietnam
| | - Khanh B Vu
- Department of Chemical Engineering, School of Biotechnology, International University, Quarter 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 700000, Vietnam.,Vietnam National University, Quarter 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 700000, Vietnam
| | - Van V Vu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
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28
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Moon M, Lee JP, Park GW, Lee JS, Park HJ, Min K. Lytic polysaccharide monooxygenase (LPMO)-derived saccharification of lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2022; 359:127501. [PMID: 35753567 DOI: 10.1016/j.biortech.2022.127501] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Given that traditional biorefineries have been based on microbial fermentation to produce useful fuels, materials, and chemicals as metabolites, saccharification is an important step to obtain fermentable sugars from biomass. It is well-known that glycosidic hydrolases (GHs) are responsible for the saccharification of recalcitrant polysaccharides through hydrolysis, but the discovery of lytic polysaccharide monooxygenase (LPMO), which is a kind of oxidative enzyme involved in cleaving polysaccharides and boosting GH performance, has profoundly changed the understanding of enzyme-based saccharification. This review briefly introduces the classification, structural information, and catalytic mechanism of LPMOs. In addition to recombinant expression strategies, synergistic effects with GH are comprehensively discussed. Challenges and perspectives for LPMO-based saccharification on a large scale are also briefly mentioned. Ultimately, this review can provide insights for constructing an economically viable lignocellulose-based biorefinery system and a closed-carbon loop to cope with climate change.
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Affiliation(s)
- Myounghoon Moon
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Joon-Pyo Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Gwon Woo Park
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Jin-Suk Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Hyun June Park
- Department of Biotechnology, Duksung Women's University, Seoul 01369, Republic of Korea
| | - Kyoungseon Min
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea.
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29
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Long L, Hu Y, Sun F, Gao W, Hao Z, Yin H. Advances in lytic polysaccharide monooxygenases with the cellulose-degrading auxiliary activity family 9 to facilitate cellulose degradation for biorefinery. Int J Biol Macromol 2022; 219:68-83. [PMID: 35931294 DOI: 10.1016/j.ijbiomac.2022.07.240] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 11/18/2022]
Abstract
One crucial step in processing the recalcitrant lignocellulosic biomass is the fast hydrolysis of natural cellulose to fermentable sugars that can be subsequently converted to biofuels and bio-based chemicals. Recent studies have shown that lytic polysaccharide monooxygenase (LPMOs) with auxiliary activity family 9 (AA9) are capable of efficiently depolymerizing the crystalline cellulose via regioselective oxidation reaction. Intriguingly, the catalysis by AA9 LPMOs requires reductant to provide electrons, and lignin and its phenolic derivatives can be oxidized, releasing reductant to activate the reaction. The activity of AA9 LPMOs can be enhanced by in-situ generation of H2O2 in the presence of O2. Although scientific understanding of these enzymes remains somewhat unknown or controversial, structure modifications on AA9 LPMOs through protein engineering have emerged in recent years, which are prerequisite for their extensive applications in the development of cellulase-mediated lignocellulosic biorefinery processes. In this review, we critically comment on advances in studies for AA9 LPMOs, i.e., characteristic of AA9 LPMOs catalysis, external electron donors to AA9 LPMOs, especially the role of the oxidization of lignin and its derivatives, and AA9 LPMOs protein engineering as well as their extensive applications in the bioprocessing of lignocellulosic biomass. Perspectives are also highlighted for addressing the challenges.
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Affiliation(s)
- Lingfeng Long
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yun Hu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Wa Gao
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS(, Dalian 116023, China
| | - Zhikui Hao
- Institute of Applied Biotechnology, School of Medicine and Pharmaceutical Engineering, Taizhou Vocational and Technical College, Taizhou 318000, China
| | - Heng Yin
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS(, Dalian 116023, China
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30
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Dade CM, Douzi B, Cambillau C, Ball G, Voulhoux R, Forest KT. The crystal structure of CbpD clarifies substrate-specificity motifs in chitin-active lytic polysaccharide monooxygenases. Acta Crystallogr D Struct Biol 2022; 78:1064-1078. [PMID: 35916229 PMCID: PMC9344471 DOI: 10.1107/s2059798322007033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 07/08/2022] [Indexed: 11/23/2022] Open
Abstract
The 3 Å resolution crystal structure of the Pseudomonas aeruginosa virulence factor CbpD both supports and challenges the current model of how lytic polysaccharide monooxygenases bind chitin and raises interesting possibilities about how type 2 secretion-system substrates may interact with the secretion machinery. This structure also demonstrates the utility of new, AI-powered, protein structure-prediction algorithms in making challenging structural targets tractable. Pseudomonas aeruginosa secretes diverse proteins via its type 2 secretion system, including a 39 kDa chitin-binding protein, CbpD. CbpD has recently been shown to be a lytic polysaccharide monooxygenase active on chitin and to contribute substantially to virulence. To date, no structure of this virulence factor has been reported. Its first two domains are homologous to those found in the crystal structure of Vibrio cholerae GbpA, while the third domain is homologous to the NMR structure of the CBM73 domain of Cellvibrio japonicusCjLPMO10A. Here, the 3.0 Å resolution crystal structure of CbpD solved by molecular replacement is reported, which required ab initio models of each CbpD domain generated by the artificial intelligence deep-learning structure-prediction algorithm RoseTTAFold. The structure of CbpD confirms some previously reported substrate-specificity motifs among LPMOAA10s, while challenging the predictive power of others. Additionally, the structure of CbpD shows that post-translational modifications occur on the chitin-binding surface. Moreover, the structure raises interesting possibilities about how type 2 secretion-system substrates may interact with the secretion machinery and demonstrates the utility of new artificial intelligence protein structure-prediction algorithms in making challenging structural targets tractable.
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31
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Serra I, Piccinini D, Paradisi A, Ciano L, Bellei M, Bortolotti CA, Battistuzzi G, Sola M, Walton PH, Di Rocco G. Activity and substrate specificity of lytic polysaccharide monooxygenases: An ATR FTIR-based sensitive assay tested on a novel species from Pseudomonas putida. Protein Sci 2022; 31:591-601. [PMID: 34897841 PMCID: PMC8862430 DOI: 10.1002/pro.4255] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 11/06/2022]
Abstract
Pseudomonas putida W619 is a soil Gram-negative bacterium commonly used in environmental studies thanks to its ability in degrading many aromatic compounds. Its genome contains several putative carbohydrate-active enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases (PMOs). In this study, we have heterologously produced in Escherichia coli and characterized a new enzyme belonging to the AA10 family, named PpAA10 (Uniprot: B1J2U9), which contains a chitin-binding type-4 module and showed activity toward β-chitin. The active form of the enzyme was produced in E. coli exploiting the addition of a cleavable N-terminal His tag which ensured the presence of the copper-coordinating His as the first residue. Electron paramagnetic resonance spectroscopy showed signal signatures similar to those observed for the copper-binding site of chitin-cleaving PMOs. The protein was used to develop a versatile, highly sensitive, cost-effective and easy-to-apply method to detect PMO's activity exploiting attenuated total reflection-Fourier transform infrared spectroscopy and able to easily discriminate between different substrates.
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Affiliation(s)
- Ilenia Serra
- Department of Life SciencesUniversity of Modena and Reggio EmiliaModenaItaly,Present address:
BIMEF Laboratory, Department of ChemistryUniversity of AntwerpAntwerpBelgium
| | - Daniele Piccinini
- Department of Life SciencesUniversity of Modena and Reggio EmiliaModenaItaly
| | - Alessandro Paradisi
- Department of Life SciencesUniversity of Modena and Reggio EmiliaModenaItaly,Department of ChemistryUniversity of YorkYorkUK
| | - Luisa Ciano
- Department of Chemistry and GeologyUniversity of Modena and Reggio EmiliaModenaItaly,Present address:
School of ChemistryUniversity of NottinghamNottinghamUK
| | - Marzia Bellei
- Department of Life SciencesUniversity of Modena and Reggio EmiliaModenaItaly
| | | | | | - Marco Sola
- Department of Life SciencesUniversity of Modena and Reggio EmiliaModenaItaly
| | | | - Giulia Di Rocco
- Department of Life SciencesUniversity of Modena and Reggio EmiliaModenaItaly
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Li Y, Li T, Guo J, Wang G, Chen G. Expression and characterization of a novel lytic polysaccharide monooxygenase, PdLPMO9A, from the edible fungus Pleurotus djamor and its synergistic interactions with cellulase in corn straw biomass saccharification. BIORESOURCE TECHNOLOGY 2022; 348:126792. [PMID: 35121098 DOI: 10.1016/j.biortech.2022.126792] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Lytic polysaccharide monooxygenases play a unique role in biomass saccharification. A novel gene, PdLPMO9A, from Pleurotus djamor, was reported to be upregulated during the degradation of corn straw in our previous research. However, very little information is available on PdLPMO9A. Therefore, PdLPMO9A was heterologously expressed in Pichia pastoris, and biophysical characterisitics of the recombinant protein PdLPMO9A were investigated; it was shown to have superior thermostability and pH stability. PdLPMO9A markedly improved the cellulase-mediated saccharification of corn straw, when the dosage of PdLPMO9A was 0.66 mg/g corn straw and hydrolysis time was 48 h. When CuSO4 was added at a concentration of 0.1 mM, glucose yield rose by a further 28.16%. In light of these findings, it was concluded that PdLPMO9A has the potential to function as an essential component of a cellulase cocktail capable of ensuring the saccharification of corn straw biomass.
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Affiliation(s)
- Yanli Li
- College of Life Science, Jilin Agricultural University, Jilin 130118, China; Key laboratory of straw comprehensive utilization and black soil conservation, Education Ministry of China, Jilin Agricultural University, Jilin 130118, China.
| | - Tongbing Li
- College of Life Science, Jilin Agricultural University, Jilin 130118, China
| | - Juntong Guo
- College of Life Science, Jilin Agricultural University, Jilin 130118, China
| | - Gang Wang
- College of Life Science, Jilin Agricultural University, Jilin 130118, China; Key laboratory of straw comprehensive utilization and black soil conservation, Education Ministry of China, Jilin Agricultural University, Jilin 130118, China
| | - Guang Chen
- College of Life Science, Jilin Agricultural University, Jilin 130118, China; Key laboratory of straw comprehensive utilization and black soil conservation, Education Ministry of China, Jilin Agricultural University, Jilin 130118, China
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Karnaouri A, Chorozian K, Zouraris D, Karantonis A, Topakas E, Rova U, Christakopoulos P. Lytic polysaccharide monooxygenases as powerful tools in enzymatically assisted preparation of nano-scaled cellulose from lignocellulose: A review. BIORESOURCE TECHNOLOGY 2022; 345:126491. [PMID: 34871721 DOI: 10.1016/j.biortech.2021.126491] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/28/2021] [Accepted: 11/30/2021] [Indexed: 06/13/2023]
Abstract
Nanocellulose, either in the form of fibers or crystals, constitutes a renewable, biobased, biocompatible material with advantageous mechanical properties that can be isolated from lignocellulosic biomass. Enzyme-assisted isolation of nanocellulose is an attractive, environmentally friendly approach that leads to products of higher quality compared to their chemically prepared counterparts. Lytic polysaccharide monooxygenases (LPMOs) are enzymes that oxidatively cleave the β-1,4-glycosidic bond of polysaccharides upon activation of O2 or H2O2 and presence of an electron donor. Their use for treatment of cellulose fibers towards the preparation of nano-scaled cellulose is related to the ability of LPMOs to create nicking points on the fiber surface, thus facilitating fiber disruption and separation. The aim of this review is to describe the mode of action of LPMOs on cellulose fibers towards the isolation of nanostructures, thus highlighting their great potential for the production of nanocellulose as a novel value added product from lignocellulose.
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Affiliation(s)
- Anthi Karnaouri
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Lab, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece; Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
| | - Koar Chorozian
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Lab, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Dimitrios Zouraris
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou, 15780 Athens, Greece
| | - Antonis Karantonis
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou, 15780 Athens, Greece
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Lab, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Ulrika Rova
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
| | - Paul Christakopoulos
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
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Comparison of six lytic polysaccharide monooxygenases from Thermothielavioides terrestris shows that functional variation underlies the multiplicity of LPMO genes in filamentous fungi. Appl Environ Microbiol 2022; 88:e0009622. [PMID: 35080911 PMCID: PMC8939357 DOI: 10.1128/aem.00096-22] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are mono-copper enzymes that oxidatively degrade various polysaccharides. Genes encoding LPMOs in the AA9 family are abundant in filamentous fungi while their multiplicity remains elusive. We describe a detailed functional characterization of six AA9 LPMOs from the ascomycetous fungus Thermothielavioides terrestris LPH172 (syn. Thielavia terrestris). These six LPMOs were shown to be upregulated during growth on different lignocellulosic substrates in our previous study. Here, we produced them heterologously in Pichia pastoris and tested their activity on various model and native plant cell wall substrates. All six T. terrestris AA9 (TtAA9) LPMOs produced hydrogen peroxide in the absence of polysaccharide substrate and displayed peroxidase-like activity on a model substrate, yet only five of them were active on selected cellulosic substrates. TtLPMO9A and TtLPMO9E were also active on birch acetylated glucuronoxylan, but only when the xylan was combined with phosphoric acid-swollen cellulose (PASC). Another of the six AA9s, TtLPMO9G, was active on spruce arabinoglucuronoxylan mixed with PASC. TtLPMO9A, TtLPMO9E, TtLPMO9G, and TtLPMO9T could degrade tamarind xyloglucan and, with the exception of TtLPMO9T, beechwood xylan when combined with PASC. Interestingly, none of the tested enzymes were active on wheat arabinoxylan, konjac glucomannan, acetylated spruce galactoglucomannan, or cellopentaose. Overall, these functional analyses support the hypothesis that the multiplicity of the fungal LPMO genes assessed in this study relates to the complex and recalcitrant structure of lignocellulosic biomass. Our study also highlights the importance of using native substrates in functional characterization of LPMOs, as we were able to demonstrate distinct, previously unreported xylan-degrading activities of AA9 LPMOs using such substrates. IMPORTANCE The discovery of LPMOs in 2010 has revolutionized the industrial biotechnology field, mainly by increasing the efficiency of cellulolytic enzyme cocktails. Nonetheless, the biological purpose of the multiplicity of LPMO-encoding genes in filamentous fungi has remained an open question. Here, we address this point by showing that six AA9 LPMOs from a single fungal strain have various substrate preferences and activities on tested cellulosic and hemicellulosic substrates, including several native xylan substrates. Importantly, several of these activities could only be detected when using copolymeric substrates that likely resemble plant cell walls more than single fractionated polysaccharides do. Our results suggest that LPMOs have evolved to contribute to the degradation of different complex structures in plant cell walls where different biomass polymers are closely associated. This knowledge together with the elucidated novel xylanolytic activities could aid in further optimization of enzymatic cocktails for efficient degradation of lignocellulosic substrates and more.
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Méndez-Líter JA, Ayuso-Fernández I, Csarman F, de Eugenio LI, Míguez N, Plou FJ, Prieto A, Ludwig R, Martínez MJ. Lytic Polysaccharide Monooxygenase from Talaromyces amestolkiae with an Enigmatic Linker-like Region: The Role of This Enzyme on Cellulose Saccharification. Int J Mol Sci 2021; 22:13611. [PMID: 34948409 PMCID: PMC8703934 DOI: 10.3390/ijms222413611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/14/2021] [Accepted: 12/16/2021] [Indexed: 11/30/2022] Open
Abstract
The first lytic polysaccharide monooxygenase (LPMO) detected in the genome of the widespread ascomycete Talaromyces amestolkiae (TamAA9A) has been successfully expressed in Pichia pastoris and characterized. Molecular modeling of TamAA9A showed a structure similar to those from other AA9 LPMOs. Although fungal LPMOs belonging to the genera Penicillium or Talaromyces have not been analyzed in terms of regioselectivity, phylogenetic analyses suggested C1/C4 oxidation which was confirmed by HPAEC. To ascertain the function of a C-terminal linker-like region present in the wild-type sequence of the LPMO, two variants of the wild-type enzyme, one without this sequence and one with an additional C-terminal carbohydrate binding domain (CBM), were designed. The three enzymes (native, without linker and chimeric variant with a CBM) were purified in two chromatographic steps and were thermostable and active in the presence of H2O2. The transition midpoint temperature of the wild-type LPMO (Tm = 67.7 °C) and its variant with only the catalytic domain (Tm = 67.6 °C) showed the highest thermostability, whereas the presence of a CBM reduced it (Tm = 57.8 °C) and indicates an adverse effect on the enzyme structure. Besides, the potential of the different T. amestolkiae LPMO variants for their application in the saccharification of cellulosic and lignocellulosic materials was corroborated.
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Affiliation(s)
- Juan Antonio Méndez-Líter
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
| | - Iván Ayuso-Fernández
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1462 Ås, Norway;
| | - Florian Csarman
- Department of Food Science and Technology, BOKU–University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria; (F.C.); (R.L.)
| | - Laura Isabel de Eugenio
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
| | - Noa Míguez
- Instituto de Catálisis y Petroleoquímica, Spanish National Research Council (CSIC), Marie Curie 2, 28049 Madrid, Spain; (N.M.); (F.J.P.)
| | - Francisco J. Plou
- Instituto de Catálisis y Petroleoquímica, Spanish National Research Council (CSIC), Marie Curie 2, 28049 Madrid, Spain; (N.M.); (F.J.P.)
| | - Alicia Prieto
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
| | - Roland Ludwig
- Department of Food Science and Technology, BOKU–University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria; (F.C.); (R.L.)
| | - María Jesús Martínez
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
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36
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Rieder L, Stepnov AA, Sørlie M, Eijsink VG. Fast and Specific Peroxygenase Reactions Catalyzed by Fungal Mono-Copper Enzymes. Biochemistry 2021; 60:3633-3643. [PMID: 34738811 PMCID: PMC8638258 DOI: 10.1021/acs.biochem.1c00407] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/27/2021] [Indexed: 11/28/2022]
Abstract
The copper-dependent lytic polysaccharide monooxygenases (LPMOs) are receiving attention because of their role in the degradation of recalcitrant biomass and their intriguing catalytic properties. The fundamentals of LPMO catalysis remain somewhat enigmatic as the LPMO reaction is affected by a multitude of LPMO- and co-substrate-mediated (side) reactions that result in a complex reaction network. We have performed kinetic studies with two LPMOs that are active on soluble substrates, NcAA9C and LsAA9A, using various reductants typically employed for LPMO activation. Studies with NcAA9C under "monooxygenase" conditions showed that the impact of the reductant on catalytic activity is correlated with the hydrogen peroxide-generating ability of the LPMO-reductant combination, supporting the idea that a peroxygenase reaction is taking place. Indeed, the apparent monooxygenase reaction could be inhibited by a competing H2O2-consuming enzyme. Interestingly, these fungal AA9-type LPMOs were found to have higher oxidase activity than bacterial AA10-type LPMOs. Kinetic analysis of the peroxygenase activity of NcAA9C on cellopentaose revealed a fast stoichiometric conversion of high amounts of H2O2 to oxidized carbohydrate products. A kcat value of 124 ± 27 s-1 at 4 °C is 20 times higher than a previously described kcat for peroxygenase activity on an insoluble substrate (at 25 °C) and some 4 orders of magnitude higher than typical "monooxygenase" rates. Similar studies with LsAA9A revealed differences between the two enzymes but confirmed fast and specific peroxygenase activity. These results show that the catalytic site arrangement of LPMOs provides a unique scaffold for highly efficient copper redox catalysis.
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Affiliation(s)
- Lukas Rieder
- Faculty of Chemistry, Biotechnology,
and Food Sciences, Norwegian University
of Life Sciences (NMBU), P.O. Box 5003,
NO, 1432 Ås, Norway
| | - Anton A. Stepnov
- Faculty of Chemistry, Biotechnology,
and Food Sciences, Norwegian University
of Life Sciences (NMBU), P.O. Box 5003,
NO, 1432 Ås, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology,
and Food Sciences, Norwegian University
of Life Sciences (NMBU), P.O. Box 5003,
NO, 1432 Ås, Norway
| | - Vincent G.H. Eijsink
- Faculty of Chemistry, Biotechnology,
and Food Sciences, Norwegian University
of Life Sciences (NMBU), P.O. Box 5003,
NO, 1432 Ås, Norway
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37
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Quantifying Oxidation of Cellulose-Associated Glucuronoxylan by Two Lytic Polysaccharide Monooxygenases from Neurospora crassa. Appl Environ Microbiol 2021; 87:e0165221. [PMID: 34613755 PMCID: PMC8612270 DOI: 10.1128/aem.01652-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Family AA9 lytic polysaccharide monooxygenases (LPMOs) are abundant in fungi, where they catalyze oxidative depolymerization of recalcitrant plant biomass. These AA9 LPMOs cleave cellulose and some also act on hemicelluloses, primarily other (substituted) β-(1→4)-glucans. Oxidative cleavage of xylan has been shown for only a few AA9 LPMOs, and it remains unclear whether this activity is a minor side reaction or primary function. Here, we show that Neurospora crassa LPMO9F (NcLPMO9F) and the phylogenetically related, hitherto uncharacterized NcLPMO9L from N. crassa are active on both cellulose and cellulose-associated glucuronoxylan but not on glucuronoxylan alone. A newly developed method for simultaneous quantification of xylan-derived and cellulose-derived oxidized products showed that NcLPMO9F preferentially cleaves xylan when acting on a cellulose–beechwood glucuronoxylan mixture, yielding about three times more xylan-derived than cellulose-derived oxidized products. Interestingly, under similar conditions, NcLPMO9L and the previously characterized McLPMO9H, from Malbranchea cinnamomea, showed different xylan-to-cellulose preferences, giving oxidized product ratios of about 0.5:1 and 1:1, respectively, indicative of functional variation among xylan-active LPMOs. Phylogenetic and structural analysis of xylan-active AA9 LPMOs led to the identification of characteristic structural features, including unique features that do not occur in phylogenetically remote AA9 LPMOs, such as four AA9 LPMOs whose lack of activity toward glucuronoxylan was demonstrated in the present study. Taken together, the results provide a path toward discovery of additional xylan-active LPMOs and show that the huge family of AA9 LPMOs has members that preferentially act on xylan. These findings shed new light on the biological role and industrial potential of these fascinating enzymes. IMPORTANCE Plant cell wall polysaccharides are highly resilient to depolymerization by hydrolytic enzymes, partly due to cellulose chains being tightly packed in microfibrils that are covered by hemicelluloses. Lytic polysaccharide monooxygenases (LPMOs) seem well suited to attack these resilient copolymeric structures, but the occurrence and importance of hemicellulolytic activity among LPMOs remain unclear. Here, we show that certain AA9 LPMOs preferentially cleave xylan when acting on a cellulose–glucuronoxylan mixture, and that this ability is the result of protein evolution that has resulted in a clade of AA9 LPMOs with specific structural features. Our findings strengthen the notion that the vast arsenal of AA9 LPMOs in certain fungal species provides functional versatility and that AA9 LPMOs may have evolved to promote oxidative depolymerization of a wide variety of recalcitrant, copolymeric plant polysaccharide structures. These findings have implications for understanding the biological roles and industrial potential of LPMOs.
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38
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Long L, Sun L, Ding D, Chen K, Lin Q, Ding S. Two C1-oxidizing lytic polysaccharide monooxygenases from Ceriporiopsis subvermispora enhance the saccharification of wheat straw by a commercial cellulase cocktail. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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39
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Sun P, Valenzuela SV, Chunkrua P, Javier Pastor FI, Laurent CVF, Ludwig R, van Berkel WJH, Kabel MA. Oxidized Product Profiles of AA9 Lytic Polysaccharide Monooxygenases Depend on the Type of Cellulose. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2021; 9:14124-14133. [PMID: 34722005 PMCID: PMC8549066 DOI: 10.1021/acssuschemeng.1c04100] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are essential for enzymatic conversion of lignocellulose-rich biomass in the context of biofuels and platform chemicals production. Considerable insight into the mode of action of LPMOs has been obtained, but research on the cellulose specificity of these enzymes is still limited. Hence, we studied the product profiles of four fungal Auxiliary Activity family 9 (AA9) LPMOs during their oxidative cleavage of three types of cellulose: bacterial cellulose (BC), Avicel PH-101 (AVI), and regenerated amorphous cellulose (RAC). We observed that attachment of a carbohydrate-binding module 1 (CBM1) did not change the substrate specificity of LPMO9B from Myceliophthora thermophila C1 (MtLPMO9B) but stimulated the degradation of all three types of cellulose. A detailed quantification of oxidized ends in both soluble and insoluble fractions, as well as characterization of oxidized cello-oligosaccharide patterns, suggested that MtLPMO9B generates mainly oxidized cellobiose from BC, while producing oxidized cello-oligosaccharides from AVI and RAC ranged more randomly from DP2-8. Comparable product profiles, resulting from BC, AVI, and RAC oxidation, were found for three other AA9 LPMOs. These distinct cleavage profiles highlight cellulose specificity rather than an LPMO-dependent mechanism and may further reflect that the product profiles of AA9 LPMOs are modulated by different cellulose types.
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Affiliation(s)
- Peicheng Sun
- Laboratory
of Food Chemistry, Wageningen University
& Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Susana V. Valenzuela
- Department
of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
- Institute
of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain
| | - Pimvisuth Chunkrua
- Laboratory
of Food Chemistry, Wageningen University
& Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Francisco I. Javier Pastor
- Department
of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
- Institute
of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain
| | - Christophe V. F.
P. Laurent
- Biocatalysis
and Biosensing Laboratory, Department of Food Science and Technology, BOKU−University of Natural Resources and Life
Sciences, Muthgasse 18, 1190 Vienna, Austria
- Institute
of Molecular Modeling and Simulation, Department of Material Sciences
and Process Engineering, BOKU−University
of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Ludwig
- Biocatalysis
and Biosensing Laboratory, Department of Food Science and Technology, BOKU−University of Natural Resources and Life
Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Willem J. H. van Berkel
- Laboratory
of Food Chemistry, Wageningen University
& Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Mirjam A. Kabel
- Laboratory
of Food Chemistry, Wageningen University
& Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
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Rieder L, Petrović D, Väljamäe P, Eijsink VG, Sørlie M. Kinetic Characterization of a Putatively Chitin-Active LPMO Reveals a Preference for Soluble Substrates and Absence of Monooxygenase Activity. ACS Catal 2021; 11:11685-11695. [PMID: 34567832 PMCID: PMC8453653 DOI: 10.1021/acscatal.1c03344] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/24/2021] [Indexed: 12/23/2022]
Abstract
![]()
Enzymes known as
lytic polysaccharide monooxygenases (LPMOs) are
recognized as important contributors to aerobic enzymatic degradation
of recalcitrant polysaccharides such as chitin and cellulose. LPMOs
are remarkably abundant in nature, with some fungal species possessing
more than 50 LPMO genes, and the biological implications of this diversity
remain enigmatic. For example, chitin-active LPMOs have been encountered
in biological niches where chitin conversion does not seem to take
place. We have carried out an in-depth kinetic characterization of
a putatively chitin-active LPMO from Aspergillus fumigatus (AfAA11B), which, as we show here, has multiple
unusual properties, such as a low redox potential and high oxidase
activity. Furthermore, AfAA11B is hardly active on
chitin, while being very active on soluble oligomers of N-acetylglucosamine. In the presence of chitotetraose, the enzyme
can withstand considerable amounts of H2O2,
which it uses to efficiently and stoichiometrically convert this substrate.
The unique properties of AfAA11B allowed experiments
showing that it is a strict peroxygenase and does not catalyze a monooxygenase
reaction. This study shows that nature uses LPMOs for breaking glycosidic
bonds in non-polymeric substrates in reactions that depend on H2O2. The quest for the true substrates of these
enzymes, possibly carbohydrates in the cell wall of the fungus or
its competitors, will be of major interest.
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Affiliation(s)
- Lukas Rieder
- Faculty of Chemistry, Biotechnology, and Food Sciences, Norwegian University of Life Sciences (NMBU), Ås N-1432, Norway
| | - Dejan Petrović
- Faculty of Chemistry, Biotechnology, and Food Sciences, Norwegian University of Life Sciences (NMBU), Ås N-1432, Norway
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu 50090, Estonia
| | - Vincent G.H. Eijsink
- Faculty of Chemistry, Biotechnology, and Food Sciences, Norwegian University of Life Sciences (NMBU), Ås N-1432, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology, and Food Sciences, Norwegian University of Life Sciences (NMBU), Ås N-1432, Norway
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Mitra S, Prakash D, Rajabimoghadam K, Wawrzak Z, Prasad P, Wu T, Misra SK, Sharp JS, Garcia-Bosch I, Chakraborty S. De Novo Design of a Self-Assembled Artificial Copper Peptide that Activates and Reduces Peroxide. ACS Catal 2021; 11:10267-10278. [DOI: 10.1021/acscatal.1c02132] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Suchitra Mitra
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
| | - Divyansh Prakash
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
| | | | - Zdzislaw Wawrzak
- Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
| | - Pallavi Prasad
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
| | - Tong Wu
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Sandeep K. Misra
- Department of Biomolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
| | - Joshua S. Sharp
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
- Department of Biomolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
| | - Isaac Garcia-Bosch
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Saumen Chakraborty
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
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Mazurkewich S, Seveso A, Hüttner S, Brändén G, Larsbrink J. Structure of a C1/C4-oxidizing AA9 lytic polysaccharide monooxygenase from the thermophilic fungus Malbranchea cinnamomea. Acta Crystallogr D Struct Biol 2021; 77:1019-1026. [PMID: 34342275 PMCID: PMC8329866 DOI: 10.1107/s2059798321006628] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 06/25/2021] [Indexed: 11/20/2022] Open
Abstract
The thermophilic fungus Malbranchea cinnamomea contains a host of enzymes that enable its ability as an efficient degrader of plant biomass and that could be mined for industrial applications. This thermophilic fungus has been studied and found to encode eight lytic polysaccharide monooxygenases (LPMOs) from auxiliary activity family 9 (AA9), which collectively possess different substrate specificities for a range of plant cell-wall-related polysaccharides and oligosaccharides. To gain greater insight into the molecular determinants defining the different specificities, structural studies were pursued and the structure of McAA9F was determined. The enzyme contains the immunoglobulin-like fold typical of previously solved AA9 LPMO structures, but contains prominent differences in the loop regions found on the surface of the substrate-binding site. Most significantly, McAA9F has a broad substrate specificity, with activity on both crystalline and soluble polysaccharides. Moreover, it contains a small loop in a region where a large loop has been proposed to govern specificity towards oligosaccharides. The presence of the small loop leads to a considerably flatter and more open surface that is likely to enable the broad specificity of the enzyme. The enzyme contains a succinimide residue substitution, arising from intramolecular cyclization of Asp10, at a position where several homologous members contain an equivalent residue but cyclization has not previously been observed. This first structure of an AA9 LPMO from M. cinnamomea aids both the understanding of this family of enzymes and the exploration of the repertoire of industrially relevant lignocellulolytic enzymes from this fungus.
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Affiliation(s)
- Scott Mazurkewich
- Wallenberg Wood Science Center, Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Andrea Seveso
- Wallenberg Wood Science Center, Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Silvia Hüttner
- Wallenberg Wood Science Center, Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Gisela Brändén
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Johan Larsbrink
- Wallenberg Wood Science Center, Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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Calderaro F, Bevers LE, van den Berg MA. Oxidative Power: Tools for Assessing LPMO Activity on Cellulose. Biomolecules 2021; 11:biom11081098. [PMID: 34439765 PMCID: PMC8391687 DOI: 10.3390/biom11081098] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 01/22/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) have sparked a lot of research regarding their fascinating mode-of-action. Particularly, their boosting effect on top of the well-known cellulolytic enzymes in lignocellulosic hydrolysis makes them industrially relevant targets. As more characteristics of LPMO and its key role have been elucidated, the need for fast and reliable methods to assess its activity have become clear. Several aspects such as its co-substrates, electron donors, inhibiting factors, and the inhomogeneity of lignocellulose had to be considered during experimental design and data interpretation, as they can impact and often hamper outcomes. This review provides an overview of the currently available methods to measure LPMO activity, including their potential and limitations, and it is illustrated with practical examples.
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Affiliation(s)
- Federica Calderaro
- DSM Biotechnology Center, 2613 AX Delft, The Netherlands; (L.E.B.); (M.A.v.d.B.)
- Molecular Enzymolog y Group, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Correspondence: ; Tel.: +31-6-36028569
| | - Loes E. Bevers
- DSM Biotechnology Center, 2613 AX Delft, The Netherlands; (L.E.B.); (M.A.v.d.B.)
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Bhatia S, Yadav SK. Novel catalytic potential of a hyperthermostable mono‑copper oxidase (LPMO-AOAA17) for the oxidation of lignin monomers and depolymerisation of lignin dimer in aqueous media. Int J Biol Macromol 2021; 186:563-573. [PMID: 34273339 DOI: 10.1016/j.ijbiomac.2021.07.063] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/06/2021] [Accepted: 07/11/2021] [Indexed: 10/20/2022]
Abstract
Lytic polysaccharide monooxygenase (LPMO) are mono‑copper enzymes known for the oxidative cleavage of recalcitrant polysaccharides with their intriguing and unique catalytic chemistry. Such impeccable oxidation potential has made them highly valuable in the enzymatic consortia for the degradation of ligno-cellulosic biomass. Bioinformatic analysis has revealed an unannotated LPMO gene in the genome of A. oryzae. Multiple sequence alignment showed the presence of conserved "histidine brace" of LPMO in the amino acid sequence of the enzyme. The enzyme, named as LPMO-AOAA17 was recombinantly expressed in E. coli BL21 and characterised for its substrate specificity. Recombinant enzyme did not show any characteristic cleavage of polysaccharides. However, it was found to be oxidising broad range of phenolic and non-phenolic monomers of lignin. Biochemical study revealed the optimum activity of LPMO-AOAA17 at pH 7 and was highly stable and active at 100 °C. The enzyme LPMO-AOAA17 was also observed to be stable after autoclaving at 121 °C and 15 psi. Thermal stability of the LPMO-AOAA17 was further confirmed through differential scanning calorimetry. GC-MS analysis has confirmed the catalysis of LPMO-AOAA17 for the depolymerisation of lignin dimer, guaicyl glycerol β-guaicyl ether into guaiacol. This study has first time documented the identification of a hyperthermostable LPMO for oxidative cleavage of β-O-4 linkage of lignin compounds to form aromatic products in aqueous media.
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Affiliation(s)
- Simran Bhatia
- Center of Innovative and Applied Bioprocessing (CIAB), Knowledge City, Sector-81, Mohali 140306, Punjab, India
| | - Sudesh Kumar Yadav
- Center of Innovative and Applied Bioprocessing (CIAB), Knowledge City, Sector-81, Mohali 140306, Punjab, India.
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45
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C-type cytochrome-initiated reduction of bacterial lytic polysaccharide monooxygenases. Biochem J 2021; 478:2927-2944. [PMID: 34240737 PMCID: PMC8981238 DOI: 10.1042/bcj20210376] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/06/2021] [Accepted: 07/09/2021] [Indexed: 11/29/2022]
Abstract
The release of glucose from lignocellulosic waste for subsequent fermentation into biofuels holds promise for securing humankind's future energy needs. The discovery of a set of copper-dependent enzymes known as lytic polysaccharide monooxygenases (LPMOs) has galvanised new research in this area. LPMOs act by oxidatively introducing chain breaks into cellulose and other polysaccharides, boosting the ability of cellulases to act on the substrate. Although several proteins have been implicated as electron sources in fungal LPMO biochemistry, no equivalent bacterial LPMO electron donors have been previously identified, although the proteins Cbp2D and E from Cellvibrio japonicus have been implicated as potential candidates. Here we analyse a small c-type cytochrome (CjX183) present in Cellvibrio japonicus Cbp2D, and show that it can initiate bacterial CuII/I LPMO reduction and also activate LPMO-catalyzed cellulose-degradation. In the absence of cellulose, CjX183-driven reduction of the LPMO results in less H2O2 production from O2, and correspondingly less oxidative damage to the enzyme than when ascorbate is used as the reducing agent. Significantly, using CjX183 as the activator maintained similar cellulase boosting levels relative to the use of an equivalent amount of ascorbate. Our results therefore add further evidence to the impact that the choice of electron source can have on LPMO action. Furthermore, the study of Cbp2D and other similar proteins may yet reveal new insight into the redox processes governing polysaccharide degradation in bacteria.
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46
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Li Z, Zhang Y, Anankanbil S, Guo Z. Applications of nanocellulosic products in food: Manufacturing processes, structural features and multifaceted functionalities. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.03.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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47
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Wang Z, Feng S, Rovira C, Wang B. How Oxygen Binding Enhances Long‐Range Electron Transfer: Lessons From Reduction of Lytic Polysaccharide Monooxygenases by Cellobiose Dehydrogenase. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202011408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Zhanfeng Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Shishi Feng
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona 08028 Barcelona Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) Passeig Lluís Companys 08020 Barcelona Spain
| | - Binju Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
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48
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Jagadeeswaran G, Veale L, Mort AJ. Do Lytic Polysaccharide Monooxygenases Aid in Plant Pathogenesis and Herbivory? TRENDS IN PLANT SCIENCE 2021; 26:142-155. [PMID: 33097402 DOI: 10.1016/j.tplants.2020.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/07/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs), copper-dependent enzymes mainly found in fungi, bacteria, and viruses, are responsible for enabling plant infection and degradation processes. Since their discovery 10 years ago, significant progress has been made in understanding the major role these enzymes play in biomass conversion. The recent discovery of additional LPMO families in fungi and oomycetes (AA16) as well as insects (AA15) strongly suggests that LPMOs might also be involved in biological processes such as overcoming plant defenses. In this review, we aim to give a comprehensive overview of the potential role of different LPMO families from the perspective of plant defense and their multiple implications in devising new strategies for achieving crop protection from plant pathogens and insect pests.
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Affiliation(s)
- Guru Jagadeeswaran
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Lawrie Veale
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Andrew J Mort
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
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49
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Hedison TM, Breslmayr E, Shanmugam M, Karnpakdee K, Heyes DJ, Green AP, Ludwig R, Scrutton NS, Kracher D. Insights into the H 2 O 2 -driven catalytic mechanism of fungal lytic polysaccharide monooxygenases. FEBS J 2021; 288:4115-4128. [PMID: 33411405 PMCID: PMC8359147 DOI: 10.1111/febs.15704] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/09/2020] [Accepted: 01/05/2021] [Indexed: 12/20/2022]
Abstract
Fungal lytic polysaccharide monooxygenases (LPMOs) depolymerise crystalline cellulose and hemicellulose, supporting the utilisation of lignocellulosic biomass as a feedstock for biorefinery and biomanufacturing processes. Recent investigations have shown that H2O2 is the most efficient cosubstrate for LPMOs. Understanding the reaction mechanism of LPMOs with H2O2 is therefore of importance for their use in biotechnological settings. Here, we have employed a variety of spectroscopic and biochemical approaches to probe the reaction of the fungal LPMO9C from N. crassa using H2O2 as a cosubstrate and xyloglucan as a polysaccharide substrate. We show that a single ‘priming’ electron transfer reaction from the cellobiose dehydrogenase partner protein supports up to 20 H2O2‐driven catalytic cycles of a fungal LPMO. Using rapid mixing stopped‐flow spectroscopy, alongside electron paramagnetic resonance and UV‐Vis spectroscopy, we reveal how H2O2 and xyloglucan interact with the enzyme and investigate transient species that form uncoupled pathways of NcLPMO9C. Our study shows how the H2O2 cosubstrate supports fungal LPMO catalysis and leaves the enzyme in the reduced Cu+ state following a single enzyme turnover, thus preventing the need for external protons and electrons from reducing agents or cellobiose dehydrogenase and supporting the binding of H2O2 for further catalytic steps. We observe that the presence of the substrate xyloglucan stabilises the Cu+ state of LPMOs, which may prevent the formation of uncoupled side reactions.
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Affiliation(s)
- Tobias M Hedison
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Erik Breslmayr
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Muralidharan Shanmugam
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Photon Science Institute, The University of Manchester, UK
| | - Kwankao Karnpakdee
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Derren J Heyes
- Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Anthony P Green
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Daniel Kracher
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
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50
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Stepnov AA, Forsberg Z, Sørlie M, Nguyen GS, Wentzel A, Røhr ÅK, Eijsink VGH. Unraveling the roles of the reductant and free copper ions in LPMO kinetics. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:28. [PMID: 33478537 PMCID: PMC7818938 DOI: 10.1186/s13068-021-01879-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 01/07/2021] [Indexed: 05/02/2023]
Abstract
BACKGROUND Lytic polysaccharide monooxygenases (LPMOs) are monocopper enzymes that catalyze oxidative depolymerization of industrially relevant crystalline polysaccharides, such as cellulose, in a reaction that depends on an electron donor and O2 or H2O2. While it is well known that LPMOs can utilize a wide variety of electron donors, the variation in reported efficiencies of various LPMO-reductant combinations remains largely unexplained. RESULTS In this study, we describe a novel two-domain cellulose-active family AA10 LPMO from a marine actinomycete, which we have used to look more closely at the effects of the reductant and copper ions on the LPMO reaction. Our results show that ascorbate-driven LPMO reactions are extremely sensitive to very low amounts (micromolar concentrations) of free copper because reduction of free Cu(II) ions by ascorbic acid leads to formation of H2O2, which speeds up the LPMO reaction. In contrast, the use of gallic acid yields steady reactions that are almost insensitive to the presence of free copper ions. Various experiments, including dose-response studies with the enzyme, showed that under typically used reaction conditions, the rate of the reaction is limited by LPMO-independent formation of H2O2 resulting from oxidation of the reductant. CONCLUSION The strong impact of low amounts of free copper on LPMO reactions with ascorbic acid and O2, i.e. the most commonly used conditions when assessing LPMO activity, likely explains reported variations in LPMO rates. The observed differences between ascorbic acid and gallic acid show a way of making LPMO reactions less copper-dependent and illustrate that reductant effects on LPMO action need to be interpreted with great caution. In clean reactions, with minimized generation of H2O2, the (O2-driven) LPMO reaction is exceedingly slow, compared to the much faster peroxygenase reaction that occurs when adding H2O2.
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Affiliation(s)
- Anton A Stepnov
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Giang-Son Nguyen
- Department of Biotechnology and Nanomedicine, SINTEF Industry, Trondheim, Norway
| | - Alexander Wentzel
- Department of Biotechnology and Nanomedicine, SINTEF Industry, Trondheim, Norway
| | - Åsmund K Røhr
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway.
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