101
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Zhu H, Ding X, Hou Y, Li Y, Wang M. Structure elucidation and bioactivities of a new polysaccharide from Xiaojin Boletus speciosus Frost. Int J Biol Macromol 2019; 126:697-716. [DOI: 10.1016/j.ijbiomac.2018.12.216] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 12/29/2022]
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102
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Benocci T, Daly P, Aguilar-Pontes MV, Lail K, Wang M, Lipzen A, Ng V, Grigoriev IV, de Vries RP. Enzymatic Adaptation of Podospora anserina to Different Plant Biomass Provides Leads to Optimized Commercial Enzyme Cocktails. Biotechnol J 2019; 14:e1800185. [PMID: 30221832 DOI: 10.1002/biot.201800185] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 09/10/2018] [Indexed: 12/17/2023]
Abstract
As a late colonizer of herbivore dung, Podospora anserina has evolved an enzymatic machinery to degrade the more recalcitrant fraction of plant biomass, suggesting a great potential for biotechnology applications. The authors investigated its transcriptome during growth on two industrial feedstocks, soybean hulls (SBH) and corn stover (CS). Initially, CS and SBH results in the expression of hemicellulolytic and amylolytic genes, respectively, while at later time points a more diverse gene set is induced, especially for SBH. Substrate adaptation is also observed for carbon catabolism. Overall, SBH resulted in a larger diversity of expressed genes, confirming previous proteomics studies. The results not only provide an in depth view on the transcriptomic adaptation of P. anserina to substrate composition, but also point out strategies to improve saccharification of plant biomass at the industrial level.
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Affiliation(s)
- Tiziano Benocci
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Paul Daly
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Maria Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Kathleen Lail
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Mei Wang
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Vivian Ng
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, 94598, USA
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
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103
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Ramos JL, Duque E. Twenty-first-century chemical odyssey: fuels versus commodities and cell factories versus chemical plants. Microb Biotechnol 2019; 12:200-209. [PMID: 30793487 PMCID: PMC6389845 DOI: 10.1111/1751-7915.13379] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/23/2019] [Accepted: 02/01/2019] [Indexed: 12/31/2022] Open
Abstract
The harmful effects of pollution from the massive and widespread use of fossil fuels have led various organizations and governments to search for alternative energy sources. To address this, a new energy bioprocess is being developed that utilizes non-edible lignocellulose - the only sustainable source of organic carbon in nature. In this mini-review, we consider the potential use of synthetic biology to develop new-to-nature pathways for the biosynthesis of chemicals that are currently synthesized using classical industrial approaches. The number of industrial processes based on starch or lignocellulose is still very modest. Advances in the area require the development of more efficient approaches to deconstruct plant materials, better exploitation of the catalytic potential of prokaryotes and lower eukaryotes and the identification of new and useful genes for product synthesis. Further research and progress is urgently needed in order for government and industry to achieve the major milestone of transitioning 30% of the total industry to renewable sources by 2050.
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Affiliation(s)
- Juan L. Ramos
- CSIC – Estación Experimental del Zaidínc/Profesor Albareda 118008GranadaSpain
| | - Estrella Duque
- CSIC – Estación Experimental del Zaidínc/Profesor Albareda 118008GranadaSpain
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104
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Valenzuela SV, Valls C, Schink V, Sánchez D, Roncero MB, Diaz P, Martínez J, Pastor FJ. Differential activity of lytic polysaccharide monooxygenases on celluloses of different crystallinity. Effectiveness in the sustainable production of cellulose nanofibrils. Carbohydr Polym 2019; 207:59-67. [DOI: 10.1016/j.carbpol.2018.11.076] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 11/20/2018] [Accepted: 11/23/2018] [Indexed: 01/14/2023]
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105
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Chen J, Guo X, Zhu M, Chen C, Li D. Polysaccharide monooxygenase-catalyzed oxidation of cellulose to glucuronic acid-containing cello-oligosaccharides. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:42. [PMID: 30858879 PMCID: PMC6391835 DOI: 10.1186/s13068-019-1384-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Polysaccharide monooxygenases (PMOs) play an important role in the enzymatic degradation of cellulose. They have been demonstrated to able to C6-oxidize cellulose to produce C6-hexodialdoses. However, the biological function of C6 oxidation of PMOs remains unknown. In particular, it is unclear whether C6-hexodialdoses can be further oxidized to uronic acid (glucuronic acid-containing oligosaccharides). RESULTS A PMO gene, Hipmo1, was isolated from Humicola insolens and expressed in Pichia pastoris. This PMO (HiPMO1), belonging to the auxiliary activity 9 (AA9) family, was shown to able to cleave cellulose to yield non-oxidized and oxidized cello-oligosaccharides. The enzyme oxidizes C6 positions in cellulose to form glucuronic acid-containing cello-oligosaccharides, followed by hydrolysis with beta-glucosidase and beta-glucuronidase to yield glucose, glucuronic acid, and saccharic acid. This indicates that HiPMO1 can catalyze C6 oxidation of hydroxyl groups of cellulose to carboxylic groups. CONCLUSIONS HiPMO1 oxidizes C6 of cellulose to form glucuronic acid-containing cello-oligosaccharides followed by hydrolysis with beta-glucosidase and beta-glucuronidase to yield glucose, glucuronic acid, and saccharic acid, and even possibly by beta-eliminative cleavage to produce unsaturated cello-oligosaccharides. This study provides a new mechanism for cellulose cleavage by C6 oxidation of HiPMO1.
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Affiliation(s)
- Jinyin Chen
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Xiuna Guo
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Min Zhu
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Chen Chen
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Duochuan Li
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
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106
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Caldararu O, Oksanen E, Ryde U, Hedegård ED. Mechanism of hydrogen peroxide formation by lytic polysaccharide monooxygenase. Chem Sci 2019; 10:576-586. [PMID: 30746099 PMCID: PMC6334667 DOI: 10.1039/c8sc03980a] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/18/2018] [Indexed: 12/27/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-containing metalloenzymes that can cleave the glycosidic link in polysaccharides. This could become crucial for production of energy-efficient biofuels from recalcitrant polysaccharides. Although LPMOs are considered oxygenases, recent investigations have shown that H2O2 can also act as a co-substrate for LPMOs. Intriguingly, LPMOs generate H2O2 in the absence of a polysaccharide substrate. Here, we elucidate a new mechanism for H2O2 generation starting from an AA10-LPMO crystal structure with an oxygen species bound, using QM/MM calculations. The reduction level and protonation state of this oxygen-bound intermediate has been unclear. However, this information is crucial to the mechanism. We therefore investigate the oxygen-bound intermediate with quantum refinement (crystallographic refinement enhanced with QM calculations), against both X-ray and neutron data. Quantum refinement calculations suggest a Cu(ii)-O-2 system in the active site of the AA10-LPMO and a neutral protonated -NH2 state for the terminal nitrogen atom, the latter in contrast to the original interpretation. Our QM/MM calculations show that H2O2 generation is possible only from a Cu(i) center and that the most favourable reaction pathway is to involve a nearby glutamate residue, adding two electrons and two protons to the Cu(ii)-O-2 system, followed by dissociation of H2O2.
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Affiliation(s)
- Octav Caldararu
- Division of Theoretical Chemistry , Lund University , Chemical Centre , P. O. Box 124 , SE-221 00 Lund , Sweden . ;
| | - Esko Oksanen
- European Spallation Source ESS ERIC , P. O. Box 176 , SE-221 00 Lund , Sweden
- Department of Biochemistry and Structural Biology , Lund University , Chemical Centre , P. O. Box 124 , SE-221 00 Lund , Sweden
| | - Ulf Ryde
- Division of Theoretical Chemistry , Lund University , Chemical Centre , P. O. Box 124 , SE-221 00 Lund , Sweden . ;
| | - Erik D Hedegård
- Division of Theoretical Chemistry , Lund University , Chemical Centre , P. O. Box 124 , SE-221 00 Lund , Sweden . ;
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107
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Lange L, Pilgaard B, Herbst FA, Busk PK, Gleason F, Pedersen AG. Origin of fungal biomass degrading enzymes: Evolution, diversity and function of enzymes of early lineage fungi. FUNGAL BIOL REV 2019. [DOI: 10.1016/j.fbr.2018.09.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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108
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Muderspach SJ, Tandrup T, Frandsen KEH, Santoni G, Poulsen JCN, Leggio LL. Further structural studies of the lytic polysaccharide monooxygenase AoAA13 belonging to the starch-active AA13 family. ACTA ACUST UNITED AC 2019. [DOI: 10.1515/amylase-2019-0004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are recently discovered copper enzymes that cleave recalcitrant polysaccharides by oxidation. The structure of an Aspergillus oryzae LPMO from the starch degrading family AA13 (AoAA13) has previously been determined from an orthorhombic crystal grown in the presence of copper, which is photoreduced in the structure. Here we describe how crystals reliably grown in presence of Zn can be Cu-loaded post crystallization. A partly photoreduced structure was obtained by severely limiting the X-ray dose, showing that this LPMO is much more prone to photoreduction than others. A serial synchrotron crystallography structure was also obtained, showing that this technique may be promising for further studies, to reduce even further photoreduction. We additionally present a triclinic structure of AoAA13, which has less occluded ligand binding site than the orthorhombic one. The availability of the triclinic crystals prompted new ligand binding studies, which lead us to the conclusion that small starch analogues do not bind to AoAA13 to an appreciable extent. A number of disordered conformations of the metal binding histidine brace have been encountered in this and other studies, and we have previously hypothesized that this disorder may be a consequence of loss of copper. We performed molecular dynamics in the absence of active site metal, and showed that the dynamics in solution differ somewhat from the disorder observed in the crystal, though the extent is equally dramatic.
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109
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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: 157] [Impact Index Per Article: 26.2] [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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110
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Andlar M, Rezić T, Marđetko N, Kracher D, Ludwig R, Šantek B. Lignocellulose degradation: An overview of fungi and fungal enzymes involved in lignocellulose degradation. Eng Life Sci 2018; 18:768-778. [PMID: 32624871 PMCID: PMC6999254 DOI: 10.1002/elsc.201800039] [Citation(s) in RCA: 189] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/03/2018] [Accepted: 04/17/2018] [Indexed: 11/10/2022] Open
Abstract
This review aims to present current knowledge of the fungi involved in lignocellulose degradation with an overview of the various classes of lignocellulose-acting enzymes engaged in the pretreatment and saccharification step. Fungi have numerous applications and biotechnological potential for various industries including chemicals, fuel, pulp, and paper. The capability of fungi to degrade lignocellulose containing raw materials is due to their highly effective enzymatic system. Along with the hydrolytic enzymes consisting of cellulases and hemicellulases, responsible for polysaccharide degradation, they have a unique nonenzymatic oxidative system which together with ligninolytic enzymes is responsible for lignin modification and degradation. An overview of the enzymes classification is given by the Carbohydrate-Active enZymes (CAZy) database as the major database for the identification of the lignocellulolytic enzymes by their amino acid sequence similarity. Finally, the recently discovered novel class of recalcitrant polysaccharide degraders-lytic polysaccharide monooxygenases (LPMOs) are presented, because of these enzymes importance in the cellulose degradation process.
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Affiliation(s)
- Martina Andlar
- Department of Biochemical EngineeringFaculty of Food Technology and BiotechnologyUniversity of ZagrebZagrebCroatia
| | - Tonči Rezić
- Department of Biochemical EngineeringFaculty of Food Technology and BiotechnologyUniversity of ZagrebZagrebCroatia
| | - Nenad Marđetko
- Department of Biochemical EngineeringFaculty of Food Technology and BiotechnologyUniversity of ZagrebZagrebCroatia
| | - Daniel Kracher
- Department of Food Sciences and TechnologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Roland Ludwig
- Department of Food Sciences and TechnologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Božidar Šantek
- Department of Biochemical EngineeringFaculty of Food Technology and BiotechnologyUniversity of ZagrebZagrebCroatia
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111
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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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112
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Kitaoku Y, Courtade G, Petrović DM, Fukamizo T, Eijsink VGH, Aachmann FL. Resonance assignments for the apo-form of the cellulose-active lytic polysaccharide monooxygenase TaLPMO9A. BIOMOLECULAR NMR ASSIGNMENTS 2018; 12:357-361. [PMID: 30117034 DOI: 10.1007/s12104-018-9839-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 08/09/2018] [Indexed: 06/08/2023]
Abstract
The apo-form of the 24.4 kDa AA9 family lytic polysaccharide monooxygenase TaLPMO9A from Thermoascus aurantiacus has been isotopically labeled and recombinantly expressed in Pichia pastoris. In this paper, we report the 1H, 13C, and 15N chemical shift assignments, as well as an analysis of the secondary structure of the protein based on the secondary chemical shifts.
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Affiliation(s)
- Yoshihito Kitaoku
- Biochemistry-Electrochemistry Research Unit, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
| | - Gaston Courtade
- NOBIPOL, Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491, Trondheim, Norway
| | - Dejan M Petrović
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Tamo Fukamizo
- Biochemistry-Electrochemistry Research Unit, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Finn L Aachmann
- NOBIPOL, Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491, Trondheim, Norway.
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113
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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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114
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115
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116
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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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117
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Hedegård ED, Ryde U. Molecular mechanism of lytic polysaccharide monooxygenases. Chem Sci 2018; 9:3866-3880. [PMID: 29780519 PMCID: PMC5935029 DOI: 10.1039/c8sc00426a] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 03/23/2018] [Indexed: 11/23/2022] Open
Abstract
The lytic polysaccharide monooxygenases (LPMOs) are copper metalloenzymes that can enhance polysaccharide depolymerization through an oxidative mechanism and hence boost generation of biofuel from e.g. cellulose. By employing density functional theory in a combination of quantum mechanics and molecular mechanics (QM/MM), we report a complete description of the molecular mechanism of LPMOs.
The lytic polysaccharide monooxygenases (LPMOs) are copper metalloenzymes that can enhance polysaccharide depolymerization through an oxidative mechanism and hence boost generation of biofuel from e.g. cellulose. By employing density functional theory in a combination of quantum mechanics and molecular mechanics (QM/MM), we report a complete description of the molecular mechanism of LPMOs. The QM/MM scheme allows us to describe all reaction steps with a detailed protein environment and we show that this is necessary. Several active species capable of abstracting a hydrogen from the substrate have been proposed previously and starting from recent crystallographic work on a substrate–LPMO complex, we investigate previously suggested paths as well as new ones. We describe the generation of the reactive intermediates, the abstraction of a hydrogen atom from the polysaccharide substrate, as well as the final recombination step in which OH is transferred back to the substrate. We show that a superoxo [CuO2]+ complex can be protonated by a nearby histidine residue (suggested by recent mutagenesis studies and crystallographic work) and, provided an electron source is available, leads to formation of an oxyl-complex after cleavage of the O–O bond and dissociation of water. The oxyl complex either reacts with the substrate or is further protonated to a hydroxyl complex. Both the oxyl and hydroxyl complexes are also readily generated from a reaction with H2O2, which was recently suggested to be the true co-substrate, rather than O2. The C–H abstraction by the oxyl and hydroxy complexes is overall favorable with activation barriers of 69 and 94 kJ mol–1, compared to the much higher barrier (156 kJ mol–1) obtained for the copper–superoxo species. We obtain good structural agreement for intermediates for which structural data are available and the estimated reaction energies agree with experimental rate constants. Thus, our suggested mechanism is the most complete to date and concur with available experimental evidence.
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Affiliation(s)
- Erik Donovan Hedegård
- Department of Theoretical Chemistry , Lund University , P. O. Box 124 , SE-221 00 , Lund , Sweden .
| | - Ulf Ryde
- Department of Theoretical Chemistry , Lund University , P. O. Box 124 , SE-221 00 , Lund , Sweden .
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118
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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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119
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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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120
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Spertino S, Boatti L, Icardi S, Manfredi M, Cattaneo C, Marengo E, Cavaletto M. Cellulomonas fimi secretomes: In vivo and in silico approaches for the lignocellulose bioconversion. J Biotechnol 2018; 270:21-29. [PMID: 29409863 DOI: 10.1016/j.jbiotec.2018.01.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/30/2017] [Accepted: 01/26/2018] [Indexed: 12/17/2022]
Abstract
Lignocellulose degradation is a challenging step for value added products and biofuels production. Cellulomonas fimi secretes complex mixtures of carbohydrate active enzymes (CAZymes) which synergistically degrade cellulose and hemicelluloses. Their characterization may provide new insights for enzymatic cocktails implementation. Bioinformatic analysis highlighted 1127 secreted proteins, constituting the in silico secretome, graphically represented in a 2DE map. According to Blast2GO functional annotation, many of these are involved in carbohydrates metabolism. In vivo secretomes were obtained, growing C. fimi on glucose, CMC or wheat straw for 24 h. Zymography revealed degradative activity on carbohydrates and proteomic analysis identified some CAZymes, only in secretomes obtained with CMC and wheat straw. An interaction between cellobiohydrolases is proposed as a strategy adopted by soluble multimodular cellulases. Such approach can be crucial for a better characterization and industrial exploitation of the synergism among C. fimi enzymes.
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Affiliation(s)
- Stefano Spertino
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy.
| | - Lara Boatti
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Sara Icardi
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Marcello Manfredi
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy; ISALIT S.r.l., Novara, Italy
| | - Chiara Cattaneo
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Emilio Marengo
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Maria Cavaletto
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
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121
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Wang B, Johnston EM, Li P, Shaik S, Davies GJ, Walton PH, Rovira C. QM/MM Studies into the H2O2-Dependent Activity of Lytic Polysaccharide Monooxygenases: Evidence for the Formation of a Caged Hydroxyl Radical Intermediate. ACS Catal 2018. [DOI: 10.1021/acscatal.7b03888] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Binju Wang
- Departament de Química Inorgànica i Orgànica (secció de Química Orgànica) & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | | | - Pengfei Li
- Department
of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Sason Shaik
- Institute of Chemistry, The Hebrew University of Jerusalem, Givat Ram Campus, 91904 Jerusalem, Israel
| | - Gideon J. Davies
- York Structural
Biology Laboratory, Department of Chemistry, University of York, Heslington, YO10 5DD, U.K
| | - Paul H. Walton
- Department
of Chemistry, University of York, Heslington, YO10 5DD, U.K
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica (secció de Química Orgànica) & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08020 Barcelona, Spain
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122
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Production and spectroscopic characterization of lytic polysaccharide monooxygenases. Methods Enzymol 2018; 613:63-90. [DOI: 10.1016/bs.mie.2018.10.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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123
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Bertini L, Breglia R, Lambrughi M, Fantucci P, De Gioia L, Borsari M, Sola M, Bortolotti CA, Bruschi M. Catalytic Mechanism of Fungal Lytic Polysaccharide Monooxygenases Investigated by First-Principles Calculations. Inorg Chem 2017; 57:86-97. [PMID: 29232119 DOI: 10.1021/acs.inorgchem.7b02005] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are Cu-containing enzymes that facilitate the degradation of recalcitrant polysaccharides by the oxidative cleavage of glycosidic bonds. They are gaining rapidly increasing attention as key players in biomass conversion, especially for the production of second-generation biofuels. Elucidation of the detailed mechanism of the LPMO reaction is a major step toward the assessment and optimization of LPMO efficacy in industrial biotechnology, paving the way to utilization of sustainable fuel sources. Here, we used density functional theory calculations to study the reaction pathways suggested to date, exploiting a very large active-site model for a fungal AA9 LPMO and using a celloheptaose unit as a substrate mimic. We identify a copper oxyl intermediate as being responsible for H-atom abstraction from the substrate, followed by a rapid, water-assisted hydroxyl rebound, leading to substrate hydroxylation.
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Affiliation(s)
- Luca Bertini
- Department of Biotechnology and Biosciences, University of Milan-Bicocca , Piazza della Scienza 2, 20126 Milan, Italy
| | - Raffaella Breglia
- Department of Earth and Environmental Sciences, University of Milan-Bicocca , Piazza della Scienza 1, 20126 Milan, Italy
| | | | - Piercarlo Fantucci
- Department of Biotechnology and Biosciences, University of Milan-Bicocca , Piazza della Scienza 2, 20126 Milan, Italy
| | - Luca De Gioia
- Department of Biotechnology and Biosciences, University of Milan-Bicocca , Piazza della Scienza 2, 20126 Milan, Italy
| | | | | | | | - Maurizio Bruschi
- Department of Earth and Environmental Sciences, University of Milan-Bicocca , Piazza della Scienza 1, 20126 Milan, Italy
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124
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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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125
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Quantification of the catalytic performance of C1-cellulose-specific lytic polysaccharide monooxygenases. Appl Microbiol Biotechnol 2017; 102:1281-1295. [PMID: 29196788 PMCID: PMC5778151 DOI: 10.1007/s00253-017-8541-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/25/2017] [Accepted: 09/09/2017] [Indexed: 01/15/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) have recently been shown to significantly enhance the degradation of recalcitrant polysaccharides and are of interest for the production of biochemicals and bioethanol from plant biomass. The copper-containing LPMOs utilize electrons, provided by reducing agents, to oxidatively cleave polysaccharides. Here, we report the development of a β-glucosidase-assisted method to quantify the release of C1-oxidized gluco-oligosaccharides from cellulose by two C1-oxidizing LPMOs from Myceliophthora thermophila C1. Based on this quantification method, we demonstrate that the catalytic performance of both MtLPMOs is strongly dependent on pH and temperature. The obtained results indicate that the catalytic performance of LPMOs depends on the interaction of multiple factors, which are affected by both pH and temperature.
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126
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Kuusk S, Bissaro B, Kuusk P, Forsberg Z, Eijsink VGH, Sørlie M, Väljamäe P. Kinetics of H 2O 2-driven degradation of chitin by a bacterial lytic polysaccharide monooxygenase. J Biol Chem 2017; 293:523-531. [PMID: 29138240 DOI: 10.1074/jbc.m117.817593] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/31/2017] [Indexed: 11/06/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of glycosidic bonds in recalcitrant polysaccharides, such as cellulose and chitin, and are of interest in biotechnological utilization of these abundant biomaterials. It has recently been shown that LPMOs can use H2O2, instead of O2, as a cosubstrate. This peroxygenase-like reaction by a monocopper enzyme is unprecedented in nature and opens new avenues in chemistry and enzymology. Here, we provide the first detailed kinetic characterization of chitin degradation by the bacterial LPMO chitin-binding protein CBP21 using H2O2 as cosubstrate. The use of 14C-labeled chitin provided convenient and sensitive detection of the released soluble products, which enabled detailed kinetic measurements. The kcat for chitin oxidation found here (5.6 s-1) is more than an order of magnitude higher than previously reported (apparent) rate constants for reactions containing O2 but no added H2O2 The kcat/Km for H2O2-driven degradation of chitin was on the order of 106 m-1 s-1, indicating that LPMOs have catalytic efficiencies similar to those of peroxygenases. Of note, H2O2 also inactivated CBP21, but the second-order rate constant for inactivation was about 3 orders of magnitude lower than that for catalysis. In light of the observed CBP21 inactivation at higher H2O2 levels, we conclude that controlled generation of H2O2in situ seems most optimal for fueling LPMO-catalyzed oxidation of polysaccharides.
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Affiliation(s)
- Silja Kuusk
- From the Institute of Molecular and Cell Biology, University of Tartu, 51010 Tartu, Estonia
| | - Bastien Bissaro
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1433 Ås, Norway, and
| | - Piret Kuusk
- Institute of Physics, University of Tartu, 50411 Tartu, Estonia
| | - Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1433 Ås, Norway, and
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1433 Ås, Norway, and
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1433 Ås, Norway, and
| | - Priit Väljamäe
- From the Institute of Molecular and Cell Biology, University of Tartu, 51010 Tartu, Estonia,
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127
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Structural and electronic determinants of lytic polysaccharide monooxygenase reactivity on polysaccharide substrates. Nat Commun 2017; 8:1064. [PMID: 29057953 PMCID: PMC5651836 DOI: 10.1038/s41467-017-01247-3] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 08/29/2017] [Indexed: 02/02/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are industrially important copper-dependent enzymes that oxidatively cleave polysaccharides. Here we present a functional and structural characterization of two closely related AA9-family LPMOs from Lentinus similis (LsAA9A) and Collariella virescens (CvAA9A). LsAA9A and CvAA9A cleave a range of polysaccharides, including cellulose, xyloglucan, mixed-linkage glucan and glucomannan. LsAA9A additionally cleaves isolated xylan substrates. The structures of CvAA9A and of LsAA9A bound to cellulosic and non-cellulosic oligosaccharides provide insight into the molecular determinants of their specificity. Spectroscopic measurements reveal differences in copper co-ordination upon the binding of xylan and glucans. LsAA9A activity is less sensitive to the reducing agent potential when cleaving xylan, suggesting that distinct catalytic mechanisms exist for xylan and glucan cleavage. Overall, these data show that AA9 LPMOs can display different apparent substrate specificities dependent upon both productive protein-carbohydrate interactions across a binding surface and also electronic considerations at the copper active site.
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128
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Hedegård ED, Ryde U. Targeting the reactive intermediate in polysaccharide monooxygenases. J Biol Inorg Chem 2017; 22:1029-1037. [PMID: 28698982 PMCID: PMC5613103 DOI: 10.1007/s00775-017-1480-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 06/29/2017] [Indexed: 01/15/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper metalloenzymes that can enhance polysaccharide depolymerization through an oxidative mechanism, making them interesting for the production of biofuel from cellulose. However, the details of this activation are unknown; in particular, the nature of the intermediate that attacks the glycoside C-H bond in the polysaccharide is not known, and a number of different species have been suggested. The homolytic bond-dissociation energy (BDE) has often been used as a descriptor for the bond-activation power, especially for inorganic model complexes. We have employed quantum-chemical cluster calculations to estimate the BDE for a number of possible LPMO intermediates to bridge the gap between model complexes and the actual LPMO active site. The calculated BDEs suggest that the reactive intermediate is either a Cu(II)-oxyl, a Cu(III)-oxyl, or a Cu(III)-hydroxide, which indicate that O-O bond breaking occurs before the C-H activation step.
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Affiliation(s)
- Erik D. Hedegård
- Department of Chemistry, Chemical Centre, Lund University, Sölvegatan 39, Lund, Sweden
| | - Ulf Ryde
- Department of Chemistry, Chemical Centre, Lund University, Sölvegatan 39, Lund, Sweden
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129
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Courtade G, Forsberg Z, Vaaje-Kolstad G, Eijsink VGH, Aachmann FL. Chemical shift assignments for the apo-form of the catalytic domain, the linker region, and the carbohydrate-binding domain of the cellulose-active lytic polysaccharide monooxygenase ScLPMO10C. BIOMOLECULAR NMR ASSIGNMENTS 2017; 11:257-264. [PMID: 28822070 DOI: 10.1007/s12104-017-9759-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/05/2017] [Indexed: 06/07/2023]
Abstract
The apo-form of the 21.4 kDa catalytic domain and the 10.7 kDa carbohydrate binding domain of the AA10 family lytic polysaccharide monooxygenase ScLPMO10C from Streptomyces coelicolor have been isotopically labeled and recombinantly expressed in Escherichia coli. In this paper, we report the 1H, 13C, and 15N chemical shift assignments of each individual domain as well as an ensemble of the assignment for the full-length protein, including its approximately 30-amino acid long linker.
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Affiliation(s)
- Gaston Courtade
- NOBIPOL, Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491, Trondheim, Norway
| | - Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Finn L Aachmann
- NOBIPOL, Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491, Trondheim, Norway.
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130
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Bacik JP, Mekasha S, Forsberg Z, Kovalevsky AY, Vaaje-Kolstad G, Eijsink VGH, Nix JC, Coates L, Cuneo MJ, Unkefer CJ, Chen JCH. Neutron and Atomic Resolution X-ray Structures of a Lytic Polysaccharide Monooxygenase Reveal Copper-Mediated Dioxygen Binding and Evidence for N-Terminal Deprotonation. Biochemistry 2017; 56:2529-2532. [DOI: 10.1021/acs.biochem.7b00019] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- John-Paul Bacik
- Protein
Crystallography Station, Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Sophanit Mekasha
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), PO Box 5003, 1430 Ås, Norway
| | - Zarah Forsberg
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), PO Box 5003, 1430 Ås, Norway
| | - Andrey Y. Kovalevsky
- Biology
and Soft Matter Division, Oak Ridge National Laboratory, 1 Bethel
Valley Road, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States
| | - Gustav Vaaje-Kolstad
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), PO Box 5003, 1430 Ås, Norway
| | - Vincent G. H. Eijsink
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), PO Box 5003, 1430 Ås, Norway
| | - Jay C. Nix
- Advanced
Light Source, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Leighton Coates
- Biology
and Soft Matter Division, Oak Ridge National Laboratory, 1 Bethel
Valley Road, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States
| | - Matthew J. Cuneo
- Biology
and Soft Matter Division, Oak Ridge National Laboratory, 1 Bethel
Valley Road, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States
| | - Clifford J. Unkefer
- Protein
Crystallography Station, Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Julian C.-H. Chen
- Protein
Crystallography Station, Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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