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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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Guo X, Jiang L, An Y, Lu F, Liu F, Wang B. Construction and characterization of a Myceliophthora thermophila lytic polysaccharide monooxygenase mutant S174C/A93C with improved thermostability. Enzyme Microb Technol 2023; 168:110255. [PMID: 37178549 DOI: 10.1016/j.enzmictec.2023.110255] [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: 12/26/2022] [Revised: 05/05/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) can oxidatively cleave the glycosidic bonds of crystalline polysaccharides, providing more accessible sites for polysaccharide hydrolases and promoting efficient conversion of biomass. In order to promote industrial applications of LPMOs, the stability of an LPMO of Myceliophthora thermophila C1 (MtC1LPMO) was improved by adding disulfide bonds in this study. Firstly, the structural changes of wild-type (WT) MtC1LPMO at different temperatures were explored using molecular dynamics simulations, and eight mutants were selected by combining the predicted results from Disulfide by Design (DBD), Multi agent stability prediction upon point mutations (Maestro) and Bridge disulfide (BridgeD) websites. Then, the enzymatic properties of the different mutants were determined after their expression and purification, and the mutant S174C/A93C with the highest thermal stability was obtained. The specific activities of unheated S174C/A93C and WT were 160.6 ± 1.7 U/g and 174.8 ± 7.5 U/g, respectively, while those of S174C/A93C and WT treated at 70 °C for 4 h were 77.7 ± 3.4 U/g and 46.1 ± 0.4 U/g, respectively. The transition midpoint temperature of S174C/A93C was 2.7 °C higher than that of WT. The conversion efficiency of S174C/A93C for both microcrystalline cellulose and corn straw was about 1.5 times higher than that of WT. Finally, molecular dynamics simulations revealed that the introduction of disulfide bonds increased the β-sheet content of the H1-E34 region, thus improving the rigidity of the protein. Therefore, the overall structural stability of S174C/A93C was improved, which in turn improved its thermal stability.
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Affiliation(s)
- Xiao Guo
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, PR China; Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Luying Jiang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Yajing An
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Fufeng Liu
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China.
| | - Bo Wang
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, PR China.
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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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4
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Wu S, Tian J, Xie N, Adnan M, Wang J, Liu G. A sensitive, accurate, and high-throughput gluco-oligosaccharide oxidase-based HRP colorimetric method for assaying lytic polysaccharide monooxygenase activity. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:15. [PMID: 35418300 PMCID: PMC8830019 DOI: 10.1186/s13068-022-02112-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 01/28/2022] [Indexed: 11/17/2022]
Abstract
Background The AA9 (auxiliary activities) family of lytic polysaccharide monooxygenases (AA9 LPMOs) is a ubiquitous and diverse group of enzymes in the fungal kingdom. They catalyse the oxidative cleavage of glycosidic bonds in lignocellulose and exhibit great potential for biorefinery applications. Robust, high-throughput and direct methods for assaying AA9 LPMO activity, which are prerequisites for screening LPMOs with excellent properties, are still lacking. Here, we present a gluco-oligosaccharide oxidase (GOOX)-based horseradish peroxidase (HRP) colorimetric method for assaying AA9 LPMO activity. Results We cloned and expressed a GOOX gene from Sarocladium strictum in Trichoderma reesei, purified the recombinant SsGOOX, validated its properties, and developed an SsGOOX-based HRP colorimetric method for assaying cellobiose concentrations. Then, we expressed two AA9 LPMOs from Thielavia terrestris, TtAA9F and TtAA9G, in T. reesei, purified the recombinant proteins, and analysed their product profiles and regioselectivity towards phosphoric acid swollen cellulose (PASC). TtAA9F was characterized as a C1-type (class 1) LPMO, while TtAA9G was characterized as a C4-type (class 2) LPMO. Finally, the SsGOOX-based HRP colorimetric method was used to quantify the total concentration of reducing lytic products from the LPMO reaction, and the activities of both the C1- and C4-type LPMOs were analysed. These LPMOs could be effectively analysed with limits of detection (LoDs) less than 30 nmol/L, and standard curves between the A515 and LPMO concentrations with determination coefficients greater than 0.994 were obtained. Conclusions A novel, sensitive and accurate assay method that directly targets the main activity of both C1- and C4-type AA9 LPMOs was established. This method is easy to use and could be performed on a microtiter plate for high-throughput screening of AA9 LPMOs with desirable properties. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02112-2.
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5
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Guo X, An Y, Liu F, Lu F, Wang B. Lytic polysaccharide monooxygenase - A new driving force for lignocellulosic biomass degradation. BIORESOURCE TECHNOLOGY 2022; 362:127803. [PMID: 35995343 DOI: 10.1016/j.biortech.2022.127803] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) can catalyze polysaccharides by oxidative cleavage of glycosidic bonds and have catalytic activity for cellulose, hemicellulose, chitin, starch and pectin, thus playing an important role in the biomass conversion of lignocellulose. The catalytic substrates of LPMOs are different and the specific catalytic mechanism has not been fully elucidated. Although there have been many studies related to LPMOs, few have actually been put into industrial biomass conversion, which poses a challenge for their expression, regulation and application. In this review, the origin, substrate specificity, structural features, and the relationship between structure and function of LPMOs are described. Additionally, the catalytic mechanism and electron donor of LPMOs and their heterologous expression and regulation are discussed. Finally, the synergistic degradation of biomass by LPMOs with other polysaccharide hydrolases is reviewed, and their current problems and future research directions are pointed out.
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Affiliation(s)
- Xiao Guo
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, PR China; Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Yajing An
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Fufeng Liu
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300450, PR China
| | - Bo Wang
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, PR China.
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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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7
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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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A fast and easy strategy for lytic polysaccharide monooxygenase-cleavable His 6-Tag cloning, expression, and purification. Enzyme Microb Technol 2020; 143:109704. [PMID: 33375972 DOI: 10.1016/j.enzmictec.2020.109704] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 11/22/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are industrially important enzymes able to enhance the enzymatic lignocellulose saccharification in synergism with classical glycoside hydrolases. Fungal LPMOs have been classified as AA9, AA11, and AA13-16 families showing a diverse specificity for substrates such as soluble and insoluble beta-glucans, chitin, starch, and xylan, besides cellulose. These enzymes are still not fully characterized, and for example this is testify by their mechanism of oxidation regularly reviewed multiple times in the last decade. Noteworthy is that despite the extremely large abundance in the entire Tree of Life, our structural and functional knowledge is based on a restricted pool of LPMO, and probably one of the main reason reside in the challenging posed by their heterologous expression. Notably, the lack of a simple cloning protocol that could be universally applied to LPMO, hinders the conversion of the ever-increasing available genomic information to actual new enzymes. Here, we provide an easy and fast protocol for cloning, expression, and purification of active LPMOs in the following architecture: natural signal peptide, LPMO enzyme, TEV protease site, and His6-Tag. For this purpose, a commercial methanol inducible expression vector was initially modified to allow the LPMO expression containing the above characteristics. Gibson assembly, a one-step isothermal DNA assembly, was adopted for the direct assembly of intron-less or intron-containing genes and the modified expression vector. Moreover, His6-tagged LPMO constructs can be submitted to TEV proteolysis for removal of the questionable C-terminal His6-Tag, obtaining a close-to-native form of LPMO. We successfully applied this method to clone, express, and purify six LPMOs from AA9 family with different regioselectivities. The proposed protocol, provided as step-by-step, could be virtually applied in many laboratories thanks to the choice of popular and commons materials.
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9
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Forsberg Z, Stepnov AA, Nærdal GK, Klinkenberg G, Eijsink VGH. Engineering lytic polysaccharide monooxygenases (LPMOs). Methods Enzymol 2020; 644:1-34. [PMID: 32943141 DOI: 10.1016/bs.mie.2020.04.052] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are mono-copper enzymes that catalyze the hydroxylation of glycosidic bonds found in the most abundant and recalcitrant polysaccharides on Earth. Since their discovery in 2010, these enzymes have received extensive attention in both fundamental and applied research due to their remarkable oxidative power and synergistic interplay with hydrolytic enzymes. The harsh and unnatural conditions used in industrial enzymatic saccharification processes and the sensitivity of LPMOs for damage induced by reactive oxygen species call for enzyme engineering to develop LPMOs to become robust industrial biocatalysts. Other engineering targets include improved catalytic activity, adjusted substrate specificity and the introduction of completely new activities. Reaching these targets not only requires appropriate methods for measuring enzyme activity, but also requires in-depth knowledge of the active site and the reaction mechanism, which is yet to be achieved in the LPMO field. Here we describe what has been done in the LPMO engineering field so far. Furthermore, we address the difficulties involved in properly assessing LPMO functionality, which are due to common side reactions taking place in LPMO reactions and which complicate screening methods.
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Affiliation(s)
- Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Anton A Stepnov
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Guro Kruge Nærdal
- Department of Biotechnology and Nanomedicine, SINTEF Industry, Trondheim, Norway
| | - Geir Klinkenberg
- Department of Biotechnology and Nanomedicine, SINTEF Industry, Trondheim, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway.
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Kojima Y, Várnai A, Eijsink VGH, Yoshida M. The Role of Lytic Polysaccharide Monooxygenases in Wood Rotting Basidiomycetes. TRENDS GLYCOSCI GLYC 2020. [DOI: 10.4052/tigg.2020.7j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Yuka Kojima
- Institute of Global Innovation, Tokyo University of Agriculture and Technology
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences
| | - Vincent G. H. Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences
| | - Makoto Yoshida
- Department of Environmental and Natural Resource Science, Tokyo University of Agriculture and Technology
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11
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Kojima Y, Várnai A, Eijsink VGH, Yoshida M. The Role of Lytic Polysaccharide Monooxygenases in Wood Rotting Basidiomycetes. TRENDS GLYCOSCI GLYC 2020. [DOI: 10.4052/tigg.2020.7e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Yuka Kojima
- Institute of Global Innovation, Tokyo University of Agriculture and Technology
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences
| | - Vincent G. H. Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences
| | - Makoto Yoshida
- Department of Environmental and Natural Resource Science, Tokyo University of Agriculture and Technology
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12
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Zhou X, Zhu H. Current understanding of substrate specificity and regioselectivity of LPMOs. BIORESOUR BIOPROCESS 2020. [DOI: 10.1186/s40643-020-0300-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
AbstractRenewable biomass such as cellulose and chitin are the most abundant sustainable sources of energy and materials. However, due to the low degradation efficiency of these recalcitrant substrates by conventional hydrolases, these biomass resources cannot be utilized efficiently. In 2010, the discovery of lytic polysaccharide monooxygenases (LPMOs) led to a major breakthrough. Currently, LPMOs are distributed in 7 families in CAZy database, including AA9–11 and AA13–16, with different species origins, substrate specificity and oxidative regioselectivity. Effective application of LPMOs in the biotransformation of biomass resources needs the elucidation of the molecular basis of their function. Since the discovery of LPMOs, great advances have been made in the study of their substrate specificity and regioselectivity, as well as their structural basis, which will be reviewed below.
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13
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Filandr F, Kavan D, Kracher D, Laurent CV, Ludwig R, Man P, Halada P. Structural Dynamics of Lytic Polysaccharide Monooxygenase during Catalysis. Biomolecules 2020; 10:E242. [PMID: 32033404 PMCID: PMC7072406 DOI: 10.3390/biom10020242] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 01/22/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are industrially important oxidoreductases employed in lignocellulose saccharification. Using advanced time-resolved mass spectrometric techniques, we elucidated the structural determinants for substrate-mediated stabilization of the fungal LPMO9C from Neurosporacrassa during catalysis. LPMOs require a reduction in the active-site copper for catalytic activity. We show that copper reduction in NcLPMO9C leads to structural rearrangements and compaction around the active site. However, longer exposure to the reducing agent ascorbic acid also initiated an uncoupling reaction of the bound oxygen species, leading to oxidative damage, partial unfolding, and even fragmentation of NcLPMO9C. Interestingly, no changes in the hydrogen/deuterium exchange rate were detected upon incubation of oxidized or reduced LPMO with crystalline cellulose, indicating that the LPMO-substrate interactions are mainly side-chain mediated and neither affect intraprotein hydrogen bonding nor induce significant shielding of the protein surface. On the other hand, we observed a protective effect of the substrate, which slowed down the autooxidative damage induced by the uncoupling reaction. These observations further complement the picture of structural changes during LPMO catalysis.
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Affiliation(s)
- Frantisek Filandr
- Institute of Microbiology of the CAS, Division BioCeV, Prumyslova 595, 252 50 Vestec, Czech Republic; (F.F.); (D.K.)
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43 Prague 2, Czech Republic
| | - Daniel Kavan
- Institute of Microbiology of the CAS, Division BioCeV, Prumyslova 595, 252 50 Vestec, Czech Republic; (F.F.); (D.K.)
| | - Daniel Kracher
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria; (D.K.); (R.L.)
| | - Christophe V.F.P. Laurent
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria; (D.K.); (R.L.)
| | - Roland Ludwig
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria; (D.K.); (R.L.)
| | - Petr Man
- Institute of Microbiology of the CAS, Division BioCeV, Prumyslova 595, 252 50 Vestec, Czech Republic; (F.F.); (D.K.)
| | - Petr Halada
- Institute of Microbiology of the CAS, Division BioCeV, Prumyslova 595, 252 50 Vestec, Czech Republic; (F.F.); (D.K.)
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14
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Laurent CV, Sun P, Scheiblbrandner S, Csarman F, Cannazza P, Frommhagen M, van Berkel WJ, Oostenbrink C, Kabel MA, Ludwig R. Influence of Lytic Polysaccharide Monooxygenase Active Site Segments on Activity and Affinity. Int J Mol Sci 2019; 20:E6219. [PMID: 31835532 PMCID: PMC6940765 DOI: 10.3390/ijms20246219] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/28/2019] [Accepted: 12/07/2019] [Indexed: 12/29/2022] Open
Abstract
In past years, new lytic polysaccharide monooxygenases (LPMOs) have been discovered as distinct in their substrate specificity. Their unconventional, surface-exposed catalytic sites determine their enzymatic activities, while binding sites govern substrate recognition and regioselectivity. An additional factor influencing activity is the presence or absence of a family 1 carbohydrate binding module (CBM1) connected via a linker to the C-terminus of the LPMO. This study investigates the changes in activity induced by shortening the second active site segment (Seg2) or removing the CBM1 from Neurospora crassa LPMO9C. NcLPMO9C and generated variants have been tested on regenerated amorphous cellulose (RAC), carboxymethyl cellulose (CMC) and xyloglucan (XG) using activity assays, conversion experiments and surface plasmon resonance spectroscopy. The absence of CBM1 reduced the binding affinity and activity of NcLPMO9C, but did not affect its regioselectivity. The linker was found important for the thermal stability of NcLPMO9C and the CBM1 is necessary for efficient binding to RAC. Wild-type NcLPMO9C exhibited the highest activity and strongest substrate binding. Shortening of Seg2 greatly reduced the activity on RAC and CMC and completely abolished the activity on XG. This demonstrates that Seg2 is indispensable for substrate recognition and the formation of productive enzyme-substrate complexes.
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Affiliation(s)
- Christophe V.F.P. Laurent
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria; (C.V.F.P.L.); (S.S.); (F.C.); (P.C.)
- Institute of Molecular Modeling and Simulation, Department of Material Sciences and Process Engineering BOKU—University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria
| | - Peicheng Sun
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands; (P.S.); (M.F.); (W.J.H.v.B.); (M.A.K.)
| | - Stefan Scheiblbrandner
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria; (C.V.F.P.L.); (S.S.); (F.C.); (P.C.)
| | - Florian Csarman
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria; (C.V.F.P.L.); (S.S.); (F.C.); (P.C.)
| | - Pietro Cannazza
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria; (C.V.F.P.L.); (S.S.); (F.C.); (P.C.)
- Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy
| | - Matthias Frommhagen
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands; (P.S.); (M.F.); (W.J.H.v.B.); (M.A.K.)
| | - Willem J.H. van Berkel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands; (P.S.); (M.F.); (W.J.H.v.B.); (M.A.K.)
| | - Chris Oostenbrink
- Institute of Molecular Modeling and Simulation, Department of Material Sciences and Process Engineering BOKU—University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria
| | - Mirjam A. Kabel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands; (P.S.); (M.F.); (W.J.H.v.B.); (M.A.K.)
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria; (C.V.F.P.L.); (S.S.); (F.C.); (P.C.)
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15
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Corrêa TLR, Júnior AT, Wolf LD, Buckeridge MS, dos Santos LV, Murakami MT. An actinobacteria lytic polysaccharide monooxygenase acts on both cellulose and xylan to boost biomass saccharification. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:117. [PMID: 31168322 PMCID: PMC6509861 DOI: 10.1186/s13068-019-1449-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/22/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Lytic polysaccharide monooxygenases (LPMOs) opened a new horizon for biomass deconstruction. They use a redox mechanism not yet fully understood and the range of substrates initially envisaged to be the crystalline polysaccharides is steadily expanding to non-crystalline ones. RESULTS The enzyme KpLPMO10A from the actinomycete Kitasatospora papulosa was cloned and overexpressed in Escherichia coli cells in the functional form with native N-terminal. The enzyme can release oxidized species from chitin (C1-type oxidation) and cellulose (C1/C4-type oxidation) similarly to other AA10 members from clade II (subclade A). Interestingly, KpLPMO10A also cleaves isolated xylan (not complexed with cellulose, C4-type oxidation), a rare activity among LPMOs not described yet for the AA10 family. The synergistic effect of KpLPMO10A with Celluclast® and an endo-β-1,4-xylanase also supports this finding. The crystallographic elucidation of KpLPMO10A at 1.6 Å resolution along with extensive structural analyses did not indicate any evident difference with other characterized AA10 LPMOs at the catalytic interface, tempting us to suggest that these enzymes might also be active on xylan or that the ability to attack both crystalline and non-crystalline substrates involves yet obscure mechanisms of substrate recognition and binding. CONCLUSIONS This work expands the spectrum of substrates recognized by AA10 family, opening a new perspective for the understanding of the synergistic effect of these enzymes with canonical glycoside hydrolases to deconstruct ligno(hemi)cellulosic biomass.
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Affiliation(s)
- Thamy Lívia Ribeiro Corrêa
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP Brazil
| | - Atílio Tomazini Júnior
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP Brazil
| | - Lúcia Daniela Wolf
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP Brazil
| | | | - Leandro Vieira dos Santos
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP Brazil
| | - Mario Tyago Murakami
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP Brazil
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16
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Chylenski P, Bissaro B, Sørlie M, Røhr ÅK, Várnai A, Horn SJ, Eijsink VG. Lytic Polysaccharide Monooxygenases in Enzymatic Processing of Lignocellulosic Biomass. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00246] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Piotr Chylenski
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, N-1432 Ås, Norway
| | - Bastien Bissaro
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, N-1432 Ås, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, N-1432 Ås, Norway
| | - Åsmund K. Røhr
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, N-1432 Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, N-1432 Ås, Norway
| | - Svein J. Horn
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, N-1432 Ås, Norway
| | - Vincent G.H. Eijsink
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, N-1432 Ås, Norway
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17
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Bissaro B, Várnai A, Røhr ÅK, Eijsink VGH. Oxidoreductases and Reactive Oxygen Species in Conversion of Lignocellulosic Biomass. Microbiol Mol Biol Rev 2018; 82:e00029-18. [PMID: 30257993 PMCID: PMC6298611 DOI: 10.1128/mmbr.00029-18] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Biomass constitutes an appealing alternative to fossil resources for the production of materials and energy. The abundance and attractiveness of vegetal biomass come along with challenges pertaining to the intricacy of its structure, evolved during billions of years to face and resist abiotic and biotic attacks. To achieve the daunting goal of plant cell wall decomposition, microorganisms have developed many (enzymatic) strategies, from which we seek inspiration to develop biotechnological processes. A major breakthrough in the field has been the discovery of enzymes today known as lytic polysaccharide monooxygenases (LPMOs), which, by catalyzing the oxidative cleavage of recalcitrant polysaccharides, allow canonical hydrolytic enzymes to depolymerize the biomass more efficiently. Very recently, it has been shown that LPMOs are not classical monooxygenases in that they can also use hydrogen peroxide (H2O2) as an oxidant. This discovery calls for a revision of our understanding of how lignocellulolytic enzymes are connected since H2O2 is produced and used by several of them. The first part of this review is dedicated to the LPMO paradigm, describing knowns, unknowns, and uncertainties. We then present different lignocellulolytic redox systems, enzymatic or not, that depend on fluxes of reactive oxygen species (ROS). Based on an assessment of these putatively interconnected systems, we suggest that fine-tuning of H2O2 levels and proximity between sites of H2O2 production and consumption are important for fungal biomass conversion. In the last part of this review, we discuss how our evolving understanding of redox processes involved in biomass depolymerization may translate into industrial applications.
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Affiliation(s)
- Bastien Bissaro
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Aas, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Aas, Norway
| | - Åsmund K Røhr
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Aas, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Aas, Norway
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18
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Recent insights into lytic polysaccharide monooxygenases (LPMOs). Biochem Soc Trans 2018; 46:1431-1447. [DOI: 10.1042/bst20170549] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/14/2018] [Accepted: 08/28/2018] [Indexed: 12/24/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper enzymes discovered within the last 10 years. By degrading recalcitrant substrates oxidatively, these enzymes are major contributors to the recycling of carbon in nature and are being used in the biorefinery industry. Recently, two new families of LPMOs have been defined and structurally characterized, AA14 and AA15, sharing many of previously found structural features. However, unlike most LPMOs to date, AA14 degrades xylan in the context of complex substrates, while AA15 is particularly interesting because they expand the presence of LPMOs from the predominantly microbial to the animal kingdom. The first two neutron crystallography structures have been determined, which, together with high-resolution room temperature X-ray structures, have putatively identified oxygen species at or near the active site of LPMOs. Many recent computational and experimental studies have also investigated the mechanism of action and substrate-binding mode of LPMOs. Perhaps, the most significant recent advance is the increasing structural and biochemical evidence, suggesting that LPMOs follow different mechanistic pathways with different substrates, co-substrates and reductants, by behaving as monooxygenases or peroxygenases with molecular oxygen or hydrogen peroxide as a co-substrate, respectively.
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19
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Danneels B, Tanghe M, Desmet T. Structural Features on the Substrate-Binding Surface of Fungal Lytic Polysaccharide Monooxygenases Determine Their Oxidative Regioselectivity. Biotechnol J 2018; 14:e1800211. [PMID: 30238672 DOI: 10.1002/biot.201800211] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 08/15/2018] [Indexed: 01/15/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that oxidatively cleave many of nature's most recalcitrant polysaccharides by acting on the C1- and/or C4-carbon of the glycosidic bond. Here, the results of an extensive mutagenesis study on three LPMO representatives, Phanerochaete chrysosporium LPMO9D (C1-oxidizer), Neurospora crassa LPMO9C (C4), and Hypocrea jecorina LPMO9A (C1/C4), are reported. Using a previously published indicator diagram, the authors demonstrate that several structural determinants of LPMOs play an important role in their oxidative regioselectivity. N-glycan removal and alterations of the aromatic residues on the substrate-binding surface are shown to alter C1/C4-oxidation ratios. Removing the carbohydrate binding module (CBM) is found not to alter the regioselectivity of HjLPMO9A, although the effect of mutational changes is shown to increase in a CBM-free context. The accessibility to the solvent-exposed axial position of the copper-site reveales not to be a major regioselectivity indicator, at least not in PcLPMO9D. Interestingly, a HjLPMO9A variant lacking two surface exposed aromatic residues combines decreased binding capacity with a 22% increase in synergetic efficiency. Similarly to recent LPMO10 findings, our results suggest a complex matrix of surface-interactions that enables LPMO9s not only to bind their substrate, but also to accurately direct their oxidative force.
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Affiliation(s)
- Barbara Danneels
- Department of Biotechnology, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Magali Tanghe
- Department of Biotechnology, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Tom Desmet
- Department of Biotechnology, Ghent University, Coupure links 653, 9000 Ghent, Belgium
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20
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Frommhagen M, Westphal AH, van Berkel WJH, Kabel MA. Distinct Substrate Specificities and Electron-Donating Systems of Fungal Lytic Polysaccharide Monooxygenases. Front Microbiol 2018; 9:1080. [PMID: 29896168 PMCID: PMC5987398 DOI: 10.3389/fmicb.2018.01080] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/07/2018] [Indexed: 12/27/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are powerful enzymes that oxidatively cleave glycosidic bonds in polysaccharides. The ability of these copper enzymes to boost the degradation of lignocellulose has greatly stimulated research efforts and biocatalytic applications within the biorefinery field. Initially found as oxidizing recalcitrant substrates, such as chitin and cellulose, it is now clear that LPMOs cleave a broad range of oligo- and poly-saccharides and make use of various electron-donating systems. Herein, substrate specificities and electron-donating systems of fungal LPMOs are summarized. A closer look at LPMOs as part of the fungal enzyme machinery might provide insights into their role in fungal growth and plant-pathogen interactions to further stimulate the search for novel LPMO applications.
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Affiliation(s)
- Matthias Frommhagen
- Laboratory of Food Chemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Mirjam A Kabel
- Laboratory of Food Chemistry, Wageningen University and Research, Wageningen, Netherlands
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21
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Liu B, Kognole AA, Wu M, Westereng B, Crowley MF, Kim S, Dimarogona M, Payne CM, Sandgren M. Structural and molecular dynamics studies of a C1‐oxidizing lytic polysaccharide monooxygenase from
Heterobasidion irregulare
reveal amino acids important for substrate recognition. FEBS J 2018; 285:2225-2242. [DOI: 10.1111/febs.14472] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/28/2018] [Accepted: 04/09/2018] [Indexed: 12/29/2022]
Affiliation(s)
- Bing Liu
- Department of Molecular Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| | - Abhishek A. Kognole
- Department of Chemical and Materials Engineering University of Kentucky Lexington KY USA
| | - Miao Wu
- Department of Molecular Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| | - Bjørge Westereng
- Department of Chemistry, Biotechnology, and Food Science Norwegian University of Life Sciences Ås Norway
| | | | - Seonah Kim
- Biosciences Center National Renewable Energy Laboratory Golden CO USA
| | - Maria Dimarogona
- Department of Molecular Sciences Swedish University of Agricultural Sciences Uppsala Sweden
- Department of Chemical Engineering University of Patras Greece
| | - Christina M. Payne
- Department of Chemical and Materials Engineering University of Kentucky Lexington KY USA
- Directorate of Engineering Division of Chemical, Bioengineering, Environmental, and Transport Systems National Science Foundation Alexandria VA USA
| | - Mats Sandgren
- Department of Molecular Sciences Swedish University of Agricultural Sciences Uppsala Sweden
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22
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Bissaro B, Isaksen I, Vaaje-Kolstad G, Eijsink VGH, Røhr ÅK. How a Lytic Polysaccharide Monooxygenase Binds Crystalline Chitin. Biochemistry 2018; 57:1893-1906. [PMID: 29498832 DOI: 10.1021/acs.biochem.8b00138] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are major players in biomass conversion, both in Nature and in the biorefining industry. How the monocopper LPMO active site is positioned relative to the crystalline substrate surface to catalyze powerful, but potentially self-destructive, oxidative chemistry is one of the major questions in the field. We have adopted a multidisciplinary approach, combining biochemical, spectroscopic, and molecular modeling methods to study chitin binding by the well-studied LPMO from Serratia marcescens SmAA10A (or CBP21). The orientation of the enzyme on a single-chain substrate was determined by analyzing enzyme cutting patterns. Building on this analysis, molecular dynamics (MD) simulations were performed to study interactions between the LPMO and three different surface topologies of crystalline chitin. The resulting atomistic models showed that most enzyme-substrate interactions involve the polysaccharide chain that is to be cleaved. The models also revealed a constrained active site geometry as well as a tunnel connecting the bulk solvent to the copper site, through which only small molecules such as H2O, O2, and H2O2 can diffuse. Furthermore, MD simulations, quantum mechanics/molecular mechanics calculations, and electron paramagnetic resonance spectroscopy demonstrate that rearrangement of Cu-coordinating water molecules is necessary when binding the substrate and also provide a rationale for the experimentally observed C1 oxidative regiospecificity of SmAA10A. This study provides a first, experimentally supported, atomistic view of the interactions between an LPMO and crystalline chitin. The confinement of the catalytic center is likely crucially important for controlling the oxidative chemistry performed by LPMOs and will help guide future mechanistic studies.
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Affiliation(s)
- Bastien Bissaro
- Faculty of Chemistry, Biotechnology, and Food Science , Norwegian University of Life Sciences , Chr. M. Falsensvei 1 , N-1432 Aas , Norway
| | - Ingvild Isaksen
- Faculty of Chemistry, Biotechnology, and Food Science , Norwegian University of Life Sciences , Chr. M. Falsensvei 1 , N-1432 Aas , Norway
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology, and Food Science , Norwegian University of Life Sciences , Chr. M. Falsensvei 1 , N-1432 Aas , Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology, and Food Science , Norwegian University of Life Sciences , Chr. M. Falsensvei 1 , N-1432 Aas , Norway
| | - Åsmund K Røhr
- Faculty of Chemistry, Biotechnology, and Food Science , Norwegian University of Life Sciences , Chr. M. Falsensvei 1 , N-1432 Aas , Norway
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23
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Meier KK, Jones SM, Kaper T, Hansson H, Koetsier MJ, Karkehabadi S, Solomon EI, Sandgren M, Kelemen B. Oxygen Activation by Cu LPMOs in Recalcitrant Carbohydrate Polysaccharide Conversion to Monomer Sugars. Chem Rev 2018; 118:2593-2635. [PMID: 29155571 PMCID: PMC5982588 DOI: 10.1021/acs.chemrev.7b00421] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Natural carbohydrate polymers such as starch, cellulose, and chitin provide renewable alternatives to fossil fuels as a source for fuels and materials. As such, there is considerable interest in their conversion for industrial purposes, which is evidenced by the established and emerging markets for products derived from these natural polymers. In many cases, this is achieved via industrial processes that use enzymes to break down carbohydrates to monomer sugars. One of the major challenges facing large-scale industrial applications utilizing natural carbohydrate polymers is rooted in the fact that naturally occurring forms of starch, cellulose, and chitin can have tightly packed organizations of polymer chains with low hydration levels, giving rise to crystalline structures that are highly recalcitrant to enzymatic degradation. The topic of this review is oxidative cleavage of carbohydrate polymers by lytic polysaccharide mono-oxygenases (LPMOs). LPMOs are copper-dependent enzymes (EC 1.14.99.53-56) that, with glycoside hydrolases, participate in the degradation of recalcitrant carbohydrate polymers. Their activity and structural underpinnings provide insights into biological mechanisms of polysaccharide degradation.
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Affiliation(s)
- Katlyn K. Meier
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Stephen M. Jones
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Thijs Kaper
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, California 94304, United States
| | - Henrik Hansson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Martijn J. Koetsier
- DuPont Industrial Biosciences, Netherlands, Nieuwe Kanaal 7-S, 6709 PA Wageningen, The Netherlands
| | - Saeid Karkehabadi
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Bradley Kelemen
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, California 94304, United States
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24
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Kracher D, Andlar M, Furtmüller PG, Ludwig R. Active-site copper reduction promotes substrate binding of fungal lytic polysaccharide monooxygenase and reduces stability. J Biol Chem 2017; 293:1676-1687. [PMID: 29259126 PMCID: PMC5798298 DOI: 10.1074/jbc.ra117.000109] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/12/2017] [Indexed: 11/06/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are a class of copper-containing enzymes that oxidatively degrade insoluble plant polysaccharides and soluble oligosaccharides. Upon reductive activation, they cleave the substrate and promote biomass degradation by hydrolytic enzymes. In this study, we employed LPMO9C from Neurospora crassa, which is active toward cellulose and soluble β-glucans, to study the enzyme-substrate interaction and thermal stability. Binding studies showed that the reduction of the mononuclear active-site copper by ascorbic acid increased the affinity and the maximum binding capacity of LPMO for cellulose. The reduced redox state of the active-site copper and not the subsequent formation of the activated oxygen species increased the affinity toward cellulose. The lower affinity of oxidized LPMO could support its desorption after catalysis and allow hydrolases to access the cleavage site. It also suggests that the copper reduction is not necessarily performed in the substrate-bound state of LPMO. Differential scanning fluorimetry showed a stabilizing effect of the substrates cellulose and xyloglucan on the apparent transition midpoint temperature of the reduced, catalytically active enzyme. Oxidative auto-inactivation and destabilization were observed in the absence of a suitable substrate. Our data reveal the determinants of LPMO stability under turnover and non-turnover conditions and indicate that the reduction of the active-site copper initiates substrate binding.
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Affiliation(s)
- Daniel Kracher
- From the Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, and
| | - Martina Andlar
- From the Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, and
| | - Paul G Furtmüller
- the Division of Biochemistry, Department of Chemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Ludwig
- From the Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, and
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25
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Forsberg Z, Bissaro B, Gullesen J, Dalhus B, Vaaje-Kolstad G, Eijsink VGH. Structural determinants of bacterial lytic polysaccharide monooxygenase functionality. J Biol Chem 2017; 293:1397-1412. [PMID: 29222333 DOI: 10.1074/jbc.m117.817130] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/22/2017] [Indexed: 12/18/2022] Open
Abstract
Bacterial lytic polysaccharide monooxygenases (LPMO10s) use redox chemistry to cleave glycosidic bonds in the two foremost recalcitrant polysaccharides found in nature, namely cellulose and chitin. Analysis of correlated mutations revealed that the substrate-binding and copper-containing surface of LPMO10s composes a network of co-evolved residues and interactions, whose roles in LPMO functionality are unclear. Here, we mutated a subset of these correlated residues in a newly characterized C1/C4-oxidizing LPMO10 from Micromonospora aurantiaca (MaLPMO10B) to the corresponding residues in strictly C1-oxidizing LPMO10s. We found that surface properties near the catalytic copper, i.e. side chains likely to be involved in substrate positioning, are major determinants of the C1:C4 ratio. Several MaLPMO10B mutants almost completely lost C4-oxidizing activity while maintaining C1-oxidizing activity. These mutants also lost chitin-oxidizing activity, which is typically observed for C1/C4-oxidizing, but not for C1-oxidizing, cellulose-active LPMO10s. Selective loss in C1-oxidizing activity was not observed. Additional mutational experiments disclosed that neither truncation of the MaLPMO10B family 2 carbohydrate-binding module nor mutations altering access to the solvent-exposed axial copper coordination site significantly change the C1:C4 ratio. Importantly, several of the mutations that altered interactions with the substrate exhibited reduced stability. This effect could be explained by productive substrate binding that protects LPMOs from oxidative self-inactivation. We discuss these stability issues in view of recent findings on LPMO catalysis, such as the involvement of H2O2 Our results show that residues on the substrate-binding surface of LPMOs have co-evolved to optimize several of the interconnected properties: substrate binding and specificity, oxidative regioselectivity, catalytic efficiency, and stability.
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Affiliation(s)
- Zarah Forsberg
- From the Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway,
| | - Bastien Bissaro
- From the Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway.,INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France, and
| | - Jonathan Gullesen
- From the Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
| | - Bjørn Dalhus
- the Department of Medical Biochemistry, Institute for Clinical Medicine, University of Oslo, 0318 Oslo, Norway, and.,the Department of Microbiology, Clinic for Laboratory Medicine, Oslo University Hospital, Rikshospitalet, P. O. Box 4950, Nydalen, N-0424 Oslo, Norway
| | - Gustav Vaaje-Kolstad
- From the Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
| | - Vincent G H Eijsink
- From the Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
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