51
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Chen K, Zhang X, Long L, Ding S. Comparison of C4-oxidizing and C1/C4-oxidizing AA9 LPMOs in substrate adsorption, H 2O 2-driven activity and synergy with cellulase on celluloses of different crystallinity. Carbohydr Polym 2021; 269:118305. [PMID: 34294322 DOI: 10.1016/j.carbpol.2021.118305] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 11/15/2022]
Abstract
Two C1/C4-oxidizing AA9 lytic polysaccharide monooxygenases (AA9 LPMOs), AoLPMO9A and AoLPMO9B, and one C4-oxidizing AoLPMO9C from Aspergillus oryzae, were characterized and compared with the well-studied C4-oxidizing NcLPMO9C. NcLPMO9C and AoLPMO9C harboring carbohydrate-binding module 1 (CBM1) exhibited much stronger adsorption capacity than AoLPMO9A and B without CBM1. The binding affinity is crucial for the efficacy of H2O2 as cosubstrate and oxidative activity of AA9 LPMOs on crystalline cellulose. C4-oxidizing AA9 LPMOs had a striking boosting effect on cellobiohydrolase I (CBHI), while C1/C4-oxidizing AA9 LPMOs boosted CBHII and endoglucanase I (EGI) activity. Our results indicated that two types of AA9 LPMOs with different modularities and regioselectivities varied in cellulose adsorption, H2O2-driven activity and synergy with cellulase on celluloses of different crystallinity which could complement each other in lignocellulose degradation. C4-oxidizing AA9 LPMOs with CBM1 were particularly essential in cellulase cocktail due to high H2O2-driven activity and a striking boosting effect on CBHI.
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Affiliation(s)
- Kaixiang Chen
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Xi Zhang
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Liangkun Long
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Shaojun Ding
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
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52
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Ipsen JØ, Hernández-Rollán C, Muderspach SJ, Brander S, Bertelsen AB, Jensen PE, Nørholm MHH, Lo Leggio L, Johansen KS. Copper binding and reactivity at the histidine brace motif: insights from mutational analysis of the Pseudomonas fluorescens copper chaperone CopC. FEBS Lett 2021; 595:1708-1720. [PMID: 33896006 DOI: 10.1002/1873-3468.14092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 11/11/2022]
Abstract
The histidine brace (His-brace) is a copper-binding motif that is associated with both oxidative enzymes and proteinaceous copper chaperones. Here, we used biochemical and structural methods to characterize mutants of a His-brace-containing copper chaperone from Pseudomonas fluorescens (PfCopC). A total of 15 amino acid variants in primary and second-sphere residues were produced and characterized in terms of their copper binding and redox properties. PfCopC has a very high affinity for Cu(II) and also binds Cu(I). A high reorganization barrier likely prevents redox cycling and, thus, catalysis. In contrast, mutations in the conserved second-sphere Glu27 enable slow oxidation of ascorbate. The crystal structure of the variant E27A confirmed copper binding at the His-brace. Unexpectedly, Asp83 at the equatorial position was shown to be indispensable for Cu(II) binding in the His-brace of PfCopC. A PfCopC mutant that was designed to mimic the His-brace from lytic polysaccharide monooxygenase-like family X325 did not bind Cu(II), but was still able to bind Cu(I). These results highlight the importance of the proteinaceous environment around the copper His-brace for reactivity and, thus, the difference between enzyme and chaperone.
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Affiliation(s)
- Johan Ø Ipsen
- Department of Plant and Environmental Sciences, Copenhagen University, Frederiksberg, Denmark
| | - Cristina Hernández-Rollán
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Søren Brander
- Department of Geosciences and Natural Resource Management, Copenhagen University, Frederiksberg, Denmark
| | - Andreas B Bertelsen
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Poul Erik Jensen
- Department of Food Science, University of Copenhagen, Frederiksberg, Denmark
| | - Morten H H Nørholm
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Katja S Johansen
- Department of Geosciences and Natural Resource Management, Copenhagen University, Frederiksberg, Denmark
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53
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Discovery of fungal oligosaccharide-oxidising flavo-enzymes with previously unknown substrates, redox-activity profiles and interplay with LPMOs. Nat Commun 2021; 12:2132. [PMID: 33837197 PMCID: PMC8035211 DOI: 10.1038/s41467-021-22372-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 03/09/2021] [Indexed: 12/14/2022] Open
Abstract
Oxidative plant cell-wall processing enzymes are of great importance in biology and biotechnology. Yet, our insight into the functional interplay amongst such oxidative enzymes remains limited. Here, a phylogenetic analysis of the auxiliary activity 7 family (AA7), currently harbouring oligosaccharide flavo-oxidases, reveals a striking abundance of AA7-genes in phytopathogenic fungi and Oomycetes. Expression of five fungal enzymes, including three from unexplored clades, expands the AA7-substrate range and unveils a cellooligosaccharide dehydrogenase activity, previously unknown within AA7. Sequence and structural analyses identify unique signatures distinguishing the strict dehydrogenase clade from canonical AA7 oxidases. The discovered dehydrogenase directly is able to transfer electrons to an AA9 lytic polysaccharide monooxygenase (LPMO) and fuel cellulose degradation by LPMOs without exogenous reductants. The expansion of redox-profiles and substrate range highlights the functional diversity within AA7 and sets the stage for harnessing AA7 dehydrogenases to fine-tune LPMO activity in biotechnological conversion of plant feedstocks. Microbial oxidoreductases are key in biomass breakdown. Here, the authors expand the specificity and redox scope within fungal auxiliary activity 7 family (AA7) enzymes and show that AA7 oligosaccharide dehydrogenases can directly fuel cellulose degradation by lytic polysaccharide monooxygenases.
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54
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Christensen IA, Eijsink VGH, Aachmann FL, Courtade G. 1H, 13C, 15N resonance assignment of the apo form of the small, chitin-active lytic polysaccharide monooxygenase JdLPMO10A from Jonesia denitrificans. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:79-84. [PMID: 33215349 DOI: 10.1007/s12104-020-09986-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/12/2020] [Indexed: 06/11/2023]
Abstract
The lytic polysaccharide monooxygenase JdLPMO10A is the N-terminal domain of the multimodular protein Jd1381. The isolated JdLPMO10A domain is one of the smallest chitin-active lytic polysaccharide monooxygenases known to date with a size of only 15.5 kDa. JdLPMO10A is a copper-dependent oxidative enzyme that depolymerizes chitin by hydroxylating the C1 carbon in the glycosidic bond. JdLPMO10A has been isotopically labeled and recombinantly expressed. Here, we report the 1H, 13C, 15N resonance assignment of JdLPMO10A. Secondary structural elements predicted based on the NMR assignment are in excellent agreement with the crystal structure of JdLPMO10A.
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Affiliation(s)
- Idd A Christensen
- NOBIPOL, Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491, Trondheim, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU 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
| | - Gaston Courtade
- 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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55
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Kadić A, Várnai A, Eijsink VGH, Horn SJ, Lidén G. In situ measurements of oxidation-reduction potential and hydrogen peroxide concentration as tools for revealing LPMO inactivation during enzymatic saccharification of cellulose. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:46. [PMID: 33602308 PMCID: PMC7893893 DOI: 10.1186/s13068-021-01894-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Biochemical conversion of lignocellulosic biomass to simple sugars at commercial scale is hampered by the high cost of saccharifying enzymes. Lytic polysaccharide monooxygenases (LPMOs) may hold the key to overcome economic barriers. Recent studies have shown that controlled activation of LPMOs by a continuous H2O2 supply can boost saccharification yields, while overdosing H2O2 may lead to enzyme inactivation and reduce overall sugar yields. While following LPMO action by ex situ analysis of LPMO products confirms enzyme inactivation, currently no preventive measures are available to intervene before complete inactivation. RESULTS Here, we carried out enzymatic saccharification of the model cellulose Avicel with an LPMO-containing enzyme preparation (Cellic CTec3) and H2O2 feed at 1 L bioreactor scale and followed the oxidation-reduction potential and H2O2 concentration in situ with corresponding electrode probes. The rate of oxidation of the reductant as well as the estimation of the amount of H2O2 consumed by LPMOs indicate that, in addition to oxidative depolymerization of cellulose, LPMOs consume H2O2 in a futile non-catalytic cycle, and that inactivation of LPMOs happens gradually and starts long before the accumulation of LPMO-generated oxidative products comes to a halt. CONCLUSION Our results indicate that, in this model system, the collapse of the LPMO-catalyzed reaction may be predicted by the rate of oxidation of the reductant, the accumulation of H2O2 in the reactor or, indirectly, by a clear increase in the oxidation-reduction potential. Being able to monitor the state of the LPMO activity in situ may help maximizing the benefit of LPMO action during saccharification. Overcoming enzyme inactivation could allow improving overall saccharification yields beyond the state of the art while lowering LPMO and, potentially, cellulase loads, both of which would have beneficial consequences on process economics.
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Affiliation(s)
- Adnan Kadić
- Department of Chemical Engineering, Lund University, P.O. Box 118, 221 00, Lund, Sweden
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, NO-1432, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, NO-1432, Ås, Norway
| | - Svein Jarle Horn
- Faculty of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, NO-1432, Ås, Norway.
| | - Gunnar Lidén
- Department of Chemical Engineering, Lund University, P.O. Box 118, 221 00, Lund, Sweden.
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56
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Wang Z, Feng S, Rovira C, Wang B. How Oxygen Binding Enhances Long‐Range Electron Transfer: Lessons From Reduction of Lytic Polysaccharide Monooxygenases by Cellobiose Dehydrogenase. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202011408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Zhanfeng Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Shishi Feng
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona 08028 Barcelona Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) Passeig Lluís Companys 08020 Barcelona Spain
| | - Binju Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
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57
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Hedison TM, Breslmayr E, Shanmugam M, Karnpakdee K, Heyes DJ, Green AP, Ludwig R, Scrutton NS, Kracher D. Insights into the H 2 O 2 -driven catalytic mechanism of fungal lytic polysaccharide monooxygenases. FEBS J 2021; 288:4115-4128. [PMID: 33411405 PMCID: PMC8359147 DOI: 10.1111/febs.15704] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/09/2020] [Accepted: 01/05/2021] [Indexed: 12/20/2022]
Abstract
Fungal lytic polysaccharide monooxygenases (LPMOs) depolymerise crystalline cellulose and hemicellulose, supporting the utilisation of lignocellulosic biomass as a feedstock for biorefinery and biomanufacturing processes. Recent investigations have shown that H2O2 is the most efficient cosubstrate for LPMOs. Understanding the reaction mechanism of LPMOs with H2O2 is therefore of importance for their use in biotechnological settings. Here, we have employed a variety of spectroscopic and biochemical approaches to probe the reaction of the fungal LPMO9C from N. crassa using H2O2 as a cosubstrate and xyloglucan as a polysaccharide substrate. We show that a single ‘priming’ electron transfer reaction from the cellobiose dehydrogenase partner protein supports up to 20 H2O2‐driven catalytic cycles of a fungal LPMO. Using rapid mixing stopped‐flow spectroscopy, alongside electron paramagnetic resonance and UV‐Vis spectroscopy, we reveal how H2O2 and xyloglucan interact with the enzyme and investigate transient species that form uncoupled pathways of NcLPMO9C. Our study shows how the H2O2 cosubstrate supports fungal LPMO catalysis and leaves the enzyme in the reduced Cu+ state following a single enzyme turnover, thus preventing the need for external protons and electrons from reducing agents or cellobiose dehydrogenase and supporting the binding of H2O2 for further catalytic steps. We observe that the presence of the substrate xyloglucan stabilises the Cu+ state of LPMOs, which may prevent the formation of uncoupled side reactions.
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Affiliation(s)
- Tobias M Hedison
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Erik Breslmayr
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Muralidharan Shanmugam
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Photon Science Institute, The University of Manchester, UK
| | - Kwankao Karnpakdee
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Derren J Heyes
- Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Anthony P Green
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, UK
| | - Daniel Kracher
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Vienna, Austria
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58
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Felice AKG, Schuster C, Kadek A, Filandr F, Laurent CVFP, Scheiblbrandner S, Schwaiger L, Schachinger F, Kracher D, Sygmund C, Man P, Halada P, Oostenbrink C, Ludwig R. Chimeric Cellobiose Dehydrogenases Reveal the Function of Cytochrome Domain Mobility for the Electron Transfer to Lytic Polysaccharide Monooxygenase. ACS Catal 2021; 11:517-532. [PMID: 33489432 PMCID: PMC7818652 DOI: 10.1021/acscatal.0c05294] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/11/2020] [Indexed: 12/11/2022]
Abstract
![]()
The natural function of cellobiose
dehydrogenase (CDH) to donate
electrons from its catalytic flavodehydrogenase (DH) domain via its
cytochrome (CYT) domain to lytic polysaccharide monooxygenase (LPMO)
is an example of a highly efficient extracellular electron transfer
chain. To investigate the function of the CYT domain movement in the
two occurring electron transfer steps, two CDHs from the ascomycete Neurospora crassa (NcCDHIIA and NcCDHIIB) and five chimeric CDH enzymes created by domain
swapping were studied in combination with the fungus’ own LPMOs
(NcLPMO9C and NcLPMO9F). Kinetic
and electrochemical methods and hydrogen/deuterium exchange mass spectrometry
were used to study the domain movement, interaction, and electron
transfer kinetics. Molecular docking provided insights into the protein–protein
interface, the orientation of domains, and binding energies. We find
that the first, interdomain electron transfer step from the catalytic
site in the DH domain to the CYT domain depends on steric and electrostatic
interface complementarity and the length of the protein linker between
both domains but not on the redox potential difference between the
FAD and heme b cofactors. After CYT reduction, a
conformational change of CDH from its closed state to an open state
allows the second, interprotein electron transfer (IPET) step from
CYT to LPMO to occur by direct interaction of the b-type heme and the type-2 copper center. Chimeric CDH enzymes favor
the open state and achieve higher IPET rates by exposing the heme b cofactor to LPMO. The IPET, which is influenced by interface
complementarity and the heme b redox potential, is
very efficient with bimolecular rates between 2.9 × 105 and 1.1 × 106 M–1 s–1.
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Affiliation(s)
- Alfons K. G. Felice
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Christian Schuster
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Alan Kadek
- BIOCEV−Institute of Microbiology, The Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic
| | - Frantisek Filandr
- BIOCEV−Institute of Microbiology, The Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic
| | - 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
- Department of Material Sciences and Process Engineering, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Stefan Scheiblbrandner
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Lorenz Schwaiger
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Franziska Schachinger
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - 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
| | - Christoph Sygmund
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Petr Man
- BIOCEV−Institute of Microbiology, The Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague, Czech Republic
| | - Petr Halada
- BIOCEV−Institute of Microbiology, The Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Chris Oostenbrink
- Department of Material Sciences and Process Engineering, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Ludwig
- Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU−University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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59
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Lytic polysaccharide monooxygenases and other histidine-brace copper proteins: structure, oxygen activation and biotechnological applications. Biochem Soc Trans 2021; 49:531-540. [PMID: 33449071 PMCID: PMC7924993 DOI: 10.1042/bst20201031] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 11/17/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are mononuclear copper enzymes that catalyse the oxidative cleavage of glycosidic bonds. They are characterised by two histidine residues that coordinate copper in a configuration termed the Cu-histidine brace. Although first identified in bacteria and fungi, LPMOs have since been found in all biological kingdoms. LPMOs are now included in commercial enzyme cocktails used in industrial biorefineries. This has led to increased process yield due to the synergistic action of LPMOs with glycoside hydrolases. However, the introduction of LPMOs makes control of the enzymatic step in industrial stirred-tank reactors more challenging, and the operational stability of the enzymes is reduced. It is clear that much is still to be learned about the interaction between LPMOs and their complex natural and industrial environments, and fundamental scientific studies are required towards this end. Several atomic-resolution structures have been solved providing detailed information on the Cu-coordination sphere and the interaction with the polysaccharide substrate. However, the molecular mechanisms of LPMOs are still the subject of intense investigation; the key question being how the proteinaceous environment controls the copper cofactor towards the activation of the O-O bond in O2 and cleavage of the glycosidic bonds in polysaccharides. The need for biochemical characterisation of each putative LPMO is discussed based on recent reports showing that not all proteins with a Cu-histidine brace are enzymes.
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60
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Tuveng TR, Jensen MS, Fredriksen L, Vaaje-Kolstad G, Eijsink VGH, Forsberg Z. A thermostable bacterial lytic polysaccharide monooxygenase with high operational stability in a wide temperature range. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:194. [PMID: 33292445 PMCID: PMC7708162 DOI: 10.1186/s13068-020-01834-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Lytic polysaccharide monooxygenases (LPMOs) are oxidative, copper-dependent enzymes that function as powerful tools in the turnover of various biomasses, including lignocellulosic plant biomass. While LPMOs are considered to be of great importance for biorefineries, little is known about industrial relevant properties such as the ability to operate at high temperatures. Here, we describe a thermostable, cellulose-active LPMO from a high-temperature compost metagenome (called mgLPMO10). RESULTS MgLPMO10 was found to have the highest apparent melting temperature (83 °C) reported for an LPMO to date, and is catalytically active up to temperatures of at least 80 °C. Generally, mgLPMO10 showed good activity and operational stability over a wide temperature range. The LPMO boosted cellulose saccharification by recombinantly produced GH48 and GH6 cellobiohydrolases derived from the same metagenome, albeit to a minor extent. Cellulose saccharification studies with a commercial cellulase cocktail (Celluclast®) showed that the performance of this thermostable bacterial LPMO is comparable with that of a frequently utilized fungal LPMO from Thermoascus aurantiacus (TaLPMO9A). CONCLUSIONS The high activity and operational stability of mgLPMO10 are of both fundamental and applied interest. The ability of mgLPMO10 to perform oxidative cleavage of cellulose at 80 °C and the clear synergy with Celluclast® make this enzyme an interesting candidate in the development of thermostable enzyme cocktails for use in lignocellulosic biorefineries.
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Affiliation(s)
- Tina Rise Tuveng
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Marianne Slang Jensen
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Lasse Fredriksen
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway.
| | - Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway.
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61
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Wang Z, Feng S, Rovira C, Wang B. How Oxygen Binding Enhances Long‐Range Electron Transfer: Lessons From Reduction of Lytic Polysaccharide Monooxygenases by Cellobiose Dehydrogenase. Angew Chem Int Ed Engl 2020; 60:2385-2392. [DOI: 10.1002/anie.202011408] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/05/2020] [Indexed: 02/02/2023]
Affiliation(s)
- Zhanfeng Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Shishi Feng
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona 08028 Barcelona Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) Passeig Lluís Companys 08020 Barcelona Spain
| | - Binju Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
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Calderaro F, Keser M, Akeroyd M, Bevers LE, Eijsink VGH, Várnai A, van den Berg MA. Characterization of an AA9 LPMO from Thielavia australiensis, TausLPMO9B, under industrially relevant lignocellulose saccharification conditions. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:195. [PMID: 33292403 PMCID: PMC7706046 DOI: 10.1186/s13068-020-01836-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 11/19/2020] [Indexed: 05/02/2023]
Abstract
BACKGROUND The discovery of lytic polysaccharide monooxygenases (LPMO) has changed our perspective on enzymatic degradation of plant biomass. Through an oxidative mechanism, these enzymes are able to cleave and depolymerize various polysaccharides, acting not only on crystalline substrates such as chitin and cellulose, but also on other polysaccharides, such as xyloglucan, glucomannan and starch. Despite their widespread use, uncertainties related to substrate specificity and stereospecificity, the nature of the co-substrate, in-process stability, and the nature of the optimal reductant challenge their exploitation in biomass processing applications. RESULTS In this work, we studied the properties of a novel fungal LPMO from the thermophilic fungus Thielavia australiensis, TausLPMO9B. Heterologous expression of TausLPMO9B in Aspergillus niger yielded a glycosylated protein with a methylated N-terminal histidine showing LPMO activity. High sequence identity of the AA9 domain to that of MtLPMO9B (MYCTH_80312) from Myceliophthora thermophila (84%) indicated strictly C1-oxidizing activity on cellulose, which was confirmed experimentally by the analysis of products released from cellulose using HPAEC. The enzyme was stable and active at a pH ranging from 4 to 6, thus matching the conditions commonly used in industrial biomass processing, where a low pH (between 4 and 5) is used due to the pH-optima of commercial cellulases and a desire to limit microbial contamination. CONCLUSION While the oxidative cleavage of phosphoric acid swollen cellulose (PASC) by TausLPMO9B was boosted by the addition of H2O2 as a co-substrate, this effect was not observed during the saccharification of acid pretreated corn stover. This illustrates key differences between the lab-scale tests with artificial, lignin-free substrates and industrial settings with lignocellulosic biomass as substrate.
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Affiliation(s)
- F Calderaro
- DSM Biotechnology Center, PP 699-0310, Alexander Fleminglaan 1, 2613 AX, Delft, The Netherlands.
- Molecular Enzymology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
| | - M Keser
- DSM Biotechnology Center, PP 699-0310, Alexander Fleminglaan 1, 2613 AX, Delft, The Netherlands
| | - M Akeroyd
- DSM Biotechnology Center, PP 699-0310, Alexander Fleminglaan 1, 2613 AX, Delft, The Netherlands
| | - L E Bevers
- DSM Biotechnology Center, PP 699-0310, Alexander Fleminglaan 1, 2613 AX, Delft, The Netherlands
| | - V G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - A Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - M A van den Berg
- DSM Biotechnology Center, PP 699-0310, Alexander Fleminglaan 1, 2613 AX, Delft, The Netherlands
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63
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Kont R, Bissaro B, Eijsink VGH, Väljamäe P. Kinetic insights into the peroxygenase activity of cellulose-active lytic polysaccharide monooxygenases (LPMOs). Nat Commun 2020; 11:5786. [PMID: 33188177 PMCID: PMC7666214 DOI: 10.1038/s41467-020-19561-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/13/2020] [Indexed: 01/06/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are widely distributed in Nature, where they catalyze the hydroxylation of glycosidic bonds in polysaccharides. Despite the importance of LPMOs in the global carbon cycle and in industrial biomass conversion, the catalytic properties of these monocopper enzymes remain enigmatic. Strikingly, there is a remarkable lack of kinetic data, likely due to a multitude of experimental challenges related to the insoluble nature of LPMO substrates, like cellulose and chitin, and to the occurrence of multiple side reactions. Here, we employed competition between well characterized reference enzymes and LPMOs for the H2O2 co-substrate to kinetically characterize LPMO-catalyzed cellulose oxidation. LPMOs of both bacterial and fungal origin showed high peroxygenase efficiencies, with kcat/KmH2O2 values in the order of 105-106 M-1 s-1. Besides providing crucial insight into the cellulolytic peroxygenase reaction, these results show that LPMOs belonging to multiple families and active on multiple substrates are true peroxygenases.
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Affiliation(s)
- Riin Kont
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Bastien Bissaro
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway.,INRAE, Aix Marseille University, UMR1163 Biodiversité et Biotechnologie Fongiques, 13009, Marseille, France
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
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64
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McEvoy A, Creutzberg J, Singh RK, Bjerrum MJ, Hedegård ED. The role of the active site tyrosine in the mechanism of lytic polysaccharide monooxygenase. Chem Sci 2020; 12:352-362. [PMID: 34163601 PMCID: PMC8178957 DOI: 10.1039/d0sc05262k] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Catalytic breakdown of polysaccharides can be achieved more efficiently by means of the enzymes lytic polysaccharide monooxygenases (LPMOs). However, the LPMO mechanism has remained controversial, preventing full exploitation of their potential. One of the controversies has centered around an active site tyrosine, present in most LPMO classes. Recent investigations have for the first time obtained direct (spectroscopic) evidence for the possibility of chemical modification of this tyrosine. However, the spectroscopic features obtained in the different investigations are remarkably different, with absorption maximum at 420 and 490 nm, respectively. In this paper we use density functional theory (DFT) in a QM/MM formulation to reconcile these (apparently) conflicting results. By modeling the spectroscopy as well as the underlying reaction mechanism we can show how formation of two isomers (both involving deprotonation of tyrosine) explains the difference in the observed spectroscopic features. Both isomers have a [TyrO–Cu–OH]+ moiety with the OH in either the cis- or trans-position to a deprotonated tyrosine. Although the cis-[TyrO–Cu–OH]+ moiety is well positioned for oxidation of the substrate, preliminary calculations with the substrate reveal that the reactivity is at best moderate, making a protective role of tyrosine more likely. With QM/MM, we investigate the mechanism of tyrosine deprotonation in lytic polysaccharide monooxygenases. Our results support deprotonation and our calculated UV-vis spectra show that two isomers must be formed to match recent experiments.![]()
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Affiliation(s)
- Aina McEvoy
- Division of Theoretical Chemistry, Lund University Box 124 SE-221 00 Lund Sweden
| | - Joel Creutzberg
- Division of Theoretical Chemistry, Lund University Box 124 SE-221 00 Lund Sweden
| | - Raushan K Singh
- Department of Chemistry, University of Copenhagen Copenhagen Denmark
| | - Morten J Bjerrum
- Department of Chemistry, University of Copenhagen Copenhagen Denmark
| | - Erik D Hedegård
- Division of Theoretical Chemistry, Lund University Box 124 SE-221 00 Lund Sweden
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65
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Wang B, Wang Z, Davies GJ, Walton PH, Rovira C. Activation of O2 and H2O2 by Lytic Polysaccharide Monooxygenases. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02914] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Zhanfeng Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Gideon J. Davies
- 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 Quı́mica Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martı́ i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluı́s Companys, 23, 08020 Barcelona, Spain
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66
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Brander S, Horvath I, Ipsen JØ, Peciulyte A, Olsson L, Hernández-Rollán C, Nørholm MHH, Mossin S, Leggio LL, Probst C, Thiele DJ, Johansen KS. Biochemical evidence of both copper chelation and oxygenase activity at the histidine brace. Sci Rep 2020; 10:16369. [PMID: 33004835 PMCID: PMC7529816 DOI: 10.1038/s41598-020-73266-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/15/2020] [Indexed: 12/22/2022] Open
Abstract
Lytic polysaccharide monooxygenase (LPMO) and copper binding protein CopC share a similar mononuclear copper site. This site is defined by an N-terminal histidine and a second internal histidine side chain in a configuration called the histidine brace. To understand better the determinants of reactivity, the biochemical and structural properties of a well-described cellulose-specific LPMO from Thermoascus aurantiacus (TaAA9A) is compared with that of CopC from Pseudomonas fluorescens (PfCopC) and with the LPMO-like protein Bim1 from Cryptococcus neoformans. PfCopC is not reduced by ascorbate but is a very strong Cu(II) chelator due to residues that interacts with the N-terminus. This first biochemical characterization of Bim1 shows that it is not redox active, but very sensitive to H2O2, which accelerates the release of Cu ions from the protein. TaAA9A oxidizes ascorbate at a rate similar to free copper but through a mechanism that produce fewer reactive oxygen species. These three biologically relevant examples emphasize the diversity in how the proteinaceous environment control reactivity of Cu with O2.
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Affiliation(s)
- Søren Brander
- Department of Geoscience and Natural Resource Management, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Istvan Horvath
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Johan Ø Ipsen
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871, Frederiksberg, Denmark
| | - Ausra Peciulyte
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Lisbeth Olsson
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Cristina Hernández-Rollán
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
| | - Morten H H Nørholm
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
| | - Susanne Mossin
- Centre for Catalysis and Sustainable Chemistry, Department of Chemistry, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, 2100, Copenhagen Ø, Denmark
| | - Corinna Probst
- Department of Biochemistry, Pharmacology and Cancer Biology and Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Dennis J Thiele
- Department of Biochemistry, Pharmacology and Cancer Biology and Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Katja S Johansen
- Department of Geoscience and Natural Resource Management, University of Copenhagen, 1958, Frederiksberg, Denmark. .,Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden.
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67
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Østby H, Hansen LD, Horn SJ, Eijsink VGH, Várnai A. Enzymatic processing of lignocellulosic biomass: principles, recent advances and perspectives. J Ind Microbiol Biotechnol 2020; 47:623-657. [PMID: 32840713 PMCID: PMC7658087 DOI: 10.1007/s10295-020-02301-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023]
Abstract
Efficient saccharification of lignocellulosic biomass requires concerted development of a pretreatment method, an enzyme cocktail and an enzymatic process, all of which are adapted to the feedstock. Recent years have shown great progress in most aspects of the overall process. In particular, increased insights into the contributions of a wide variety of cellulolytic and hemicellulolytic enzymes have improved the enzymatic processing step and brought down costs. Here, we review major pretreatment technologies and different enzyme process setups and present an in-depth discussion of the various enzyme types that are currently in use. We pay ample attention to the role of the recently discovered lytic polysaccharide monooxygenases (LPMOs), which have led to renewed interest in the role of redox enzyme systems in lignocellulose processing. Better understanding of the interplay between the various enzyme types, as they may occur in a commercial enzyme cocktail, is likely key to further process improvements.
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Affiliation(s)
- Heidi Østby
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Line Degn Hansen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Svein J Horn
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway.
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68
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Lu J, Wang B, Shaik S, Lai W. QM/MM Calculations Reveal the Important Role of α-Heteroatom Substituents in Controlling Selectivity of Mononuclear Nonheme HppE-Catalyzed Reactions. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01803] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jiarui Lu
- Department of Chemistry, Renmin University of China, Beijing 100872, China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 360015, P. R. China
| | - Sason Shaik
- Institute of Chemistry and The Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Wenzhen Lai
- Department of Chemistry, Renmin University of China, Beijing 100872, China
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