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Breslmayr E, Laurent CVFP, Scheiblbrandner S, Jerkovic A, Heyes DJ, Oostenbrink C, Ludwig R, Hedison TM, Scrutton NS, Kracher D. Protein Conformational Change Is Essential for Reductive Activation of Lytic Polysaccharide Monooxygenase by Cellobiose Dehydrogenase. ACS Catal 2020; 10:4842-4853. [PMID: 32382450 PMCID: PMC7199207 DOI: 10.1021/acscatal.0c00754] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/30/2020] [Indexed: 12/30/2022]
Abstract
Large-scale protein domain dynamics and electron transfer are often associated. However, as protein motions span a broad range of time and length scales, it is often challenging to identify and thus link functionally relevant dynamic changes to electron transfer in proteins. It is hypothesized that large-scale domain motions direct electrons through a FAD and a heme b cofactor of the fungal cellobiose dehydrogenase (CDH) enzymes to the type-II copper center (T2Cu) of the polysaccharide-degrading lytic polysaccharide monooxygenases (LPMOs). However, as of yet, domain motions in CDH have not been linked formally to enzyme-catalyzed electron transfer reactions. The detailed structural features of CDH, which govern the functional conformational landscapes of the enzyme, have only been partially resolved. Here, we use a combination of pressure, viscosity, ionic strength, and temperature perturbation stopped-flow studies to probe the conformational landscape associated with the electron transfer reactions of CDH. Through the use of molecular dynamics simulations, potentiometry, and stopped-flow spectroscopy, we investigated how a conserved Tyr99 residue plays a key role in shaping the conformational landscapes for both the interdomain electron transfer reactions of CDH (from FAD to heme) and the delivery of electrons from the reduced heme cofactor to the LPMO T2Cu. Our studies show how motions gate the electron transfer within CDH and from CDH to LPMO and illustrate the conformational landscape for interdomain and interprotein electron transfer in this extracellular fungal electron transfer chain.
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Affiliation(s)
- Erik Breslmayr
- Manchester Institute of Biotechnology, The University of Manchester, M1 7DN Manchester, United Kingdom
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
- Department of Material Sciences and Process Engineering, Institute of Molecular Modeling and Simulation, Muthgasse 18, 1190 Vienna, Austria
| | - Christophe V. F. P. Laurent
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
- Department of Material Sciences and Process Engineering, Institute of Molecular Modeling and Simulation, Muthgasse 18, 1190 Vienna, Austria
| | - Stefan Scheiblbrandner
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Anita Jerkovic
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Derren J. Heyes
- Manchester Institute of Biotechnology, The University of Manchester, M1 7DN Manchester, United Kingdom
| | - Chris Oostenbrink
- Department of Material Sciences and Process Engineering, Institute of Molecular Modeling and Simulation, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Tobias M. Hedison
- Manchester Institute of Biotechnology, The University of Manchester, M1 7DN Manchester, United Kingdom
- EPSRC/BBSRC funded Future Biomanufacturing Research Hub, The Manchester Institute of Biotechnology, The University of Manchester, M1 7DN Manchester, United Kingdom
| | - Nigel S. Scrutton
- Manchester Institute of Biotechnology, The University of Manchester, M1 7DN Manchester, United Kingdom
- EPSRC/BBSRC funded Future Biomanufacturing Research Hub, The Manchester Institute of Biotechnology, The University of Manchester, M1 7DN Manchester, United Kingdom
| | - Daniel Kracher
- Manchester Institute of Biotechnology, The University of Manchester, M1 7DN Manchester, United Kingdom
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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Scheiblbrandner S, Ludwig R. Cellobiose dehydrogenase: Bioelectrochemical insights and applications. Bioelectrochemistry 2019; 131:107345. [PMID: 31494387 DOI: 10.1016/j.bioelechem.2019.107345] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/01/2019] [Accepted: 08/01/2019] [Indexed: 12/17/2022]
Abstract
Cellobiose dehydrogenase (CDH) is a flavocytochrome with a history of bioelectrochemical research dating back to 1992. During the years, it has been shown to be capable of mediated electron transfer (MET) and direct electron transfer (DET) to a variety of electrodes. This versatility of CDH originates from the separation of the catalytic flavodehydrogenase domain and the electron transferring cytochrome domain. This uncoupling of the catalytic reaction from the electron transfer process allows the application of CDH on many different electrode materials and surfaces, where it shows robust DET. Recent X-ray diffraction and small angle scattering studies provided insights into the structure of CDH and its domain mobility, which can change between a closed-state and an open-state conformation. This structural information verifies the electron transfer mechanism of CDH that was initially established by bioelectrochemical methods. A combination of DET and MET experiments has been used to investigate the catalytic mechanism and the electron transfer process of CDH and to deduce a protein structure comprising of mobile domains. Even more, electrochemical methods have been used to study the redox potentials of the FAD and the haem b cofactors of CDH or the electron transfer rates. These electrochemical experiments, their results and the application of the characterised CDHs in biosensors, biofuel cells and biosupercapacitors are combined with biochemical and structural data to provide a thorough overview on CDH as versatile bioelectrocatalyst.
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Affiliation(s)
- Stefan Scheiblbrandner
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU - University of Natural Resources and Life Sciences, Vienna, Muthgasse 11, 1190 Vienna, Austria.
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Science and Technology, BOKU - University of Natural Resources and Life Sciences, Vienna, Muthgasse 11, 1190 Vienna, Austria.
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3
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Balaž AM, Stevanović J, Ostafe R, Blazić M, Ilić Đurđić K, Fischer R, Prodanović R. Semi-rational design of cellobiose dehydrogenase for increased stability in the presence of peroxide. Mol Divers 2019; 24:593-601. [PMID: 31154590 DOI: 10.1007/s11030-019-09965-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/25/2019] [Indexed: 11/30/2022]
Abstract
Cellobiose dehydrogenase (CDH, EC 1.1.99.18) from white rot fungi Phanerochaete chrysosporium can be used for constructing biosensors and biofuel cells, for bleaching cotton in textile industry, and recently, the enzyme has found an important application in biomedicine as an antimicrobial and antibiofilm agent. Stability and activity of the wild-type (wt) CDH and mutants at methionine residues in the presence of hydrogen peroxide were investigated. Saturation mutagenesis libraries were made at the only methionine in heme domain M65 and two methionines M685 and M738 in the flavin domain that were closest to the active site. After screening the libraries, three mutants with increased activity and stability in the presence of peroxide were found, M65F with 70% of residual activity after 6 h of incubation in 0.3 M hydrogen peroxide, M738S with 80% of residual activity and M685Y with over 90% of residual activity compared to wild-type CDH that retained 40% of original activity. Combined mutants showed no activity. The most stable mutant M685Y with 5.8 times increased half-life in the presence of peroxide showed also 2.5 times increased kcat for lactose compared to wtCDH and could be good candidate for applications in biofuel cells and biocatalysis for lactobionic acid production.
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Affiliation(s)
- Ana Marija Balaž
- Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoseva 12, 11000, Belgrade, Serbia
| | - Jelena Stevanović
- Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12 - 16, 11000, Belgrade, Serbia
| | - Raluca Ostafe
- Hall for Discovery and Learning Research, Purdue University, 207 S. Martin Jischke Dr., West Lafayette, IN, 47907, USA
| | - Marija Blazić
- Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoseva 12, 11000, Belgrade, Serbia
| | - Karla Ilić Đurđić
- Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12 - 16, 11000, Belgrade, Serbia
| | - Rainer Fischer
- Institute of Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.,Single Cell Analytics Center, Indiana Bioscience Research Institute, 1345 W. 16th St. Suite 300, Indianapolis, IN, 46202, USA
| | - Radivoje Prodanović
- Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12 - 16, 11000, Belgrade, Serbia.
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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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Lisov AV, Belova OV, Vinokurova NG, Semashko TV, Lobanok AG, Leontievsky AA. Transformation of cellobiose during the interaction of cellobiose dehydrogenase and β-glucosidase of Cerrena unicolor. J Basic Microbiol 2018; 58:322-330. [DOI: 10.1002/jobm.201700399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/17/2017] [Accepted: 12/07/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Alexander V. Lisov
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms; Russian Academy of Sciences; Pushchino Moscow Region Russia
- Pushchino State Institute of Life Sciences; Pushchino Moscow Region Russia
| | - Oksana V. Belova
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms; Russian Academy of Sciences; Pushchino Moscow Region Russia
| | - Nataliya G. Vinokurova
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms; Russian Academy of Sciences; Pushchino Moscow Region Russia
| | - Tatiana V. Semashko
- Institute of Microbiology; National Academy of Sciences of Belarus; Minsk Belarus
| | - Anatolii G. Lobanok
- Institute of Microbiology; National Academy of Sciences of Belarus; Minsk Belarus
| | - Alexey A. Leontievsky
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms; Russian Academy of Sciences; Pushchino Moscow Region Russia
- Pushchino State Institute of Life Sciences; Pushchino Moscow Region Russia
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Loose JSM, Forsberg Z, Kracher D, Scheiblbrandner S, Ludwig R, Eijsink VGH, Vaaje‐Kolstad G. Activation of bacterial lytic polysaccharide monooxygenases with cellobiose dehydrogenase. Protein Sci 2016; 25:2175-2186. [PMID: 27643617 PMCID: PMC5119556 DOI: 10.1002/pro.3043] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 11/10/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) represent a recent addition to the carbohydrate-active enzymes and are classified as auxiliary activity (AA) families 9, 10, 11, and 13. LPMOs are crucial for effective degradation of recalcitrant polysaccharides like cellulose or chitin. These enzymes are copper-dependent and utilize a redox mechanism to cleave glycosidic bonds that is dependent on molecular oxygen and an external electron donor. The electrons can be provided by various sources, such as chemical compounds (e.g., ascorbate) or by enzymes (e.g., cellobiose dehydrogenases, CDHs, from fungi). Here, we demonstrate that a fungal CDH from Myriococcum thermophilum (MtCDH), can act as an electron donor for bacterial family AA10 LPMOs. We show that employing an enzyme as electron donor is advantageous since this enables a kinetically controlled supply of electrons to the LPMO. The rate of chitin oxidation by CBP21 was equal to that of cosubstrate (lactose) oxidation by MtCDH, verifying the usage of two electrons in the LPMO catalytic mechanism. Furthermore, since lactose oxidation correlates directly with the rate of LPMO catalysis, a method for indirect determination of LPMO activity is implicated. Finally, the one electron reduction of the CBP21 active site copper by MtCDH was determined to be substantially faster than chitin oxidation by the LPMO. Overall, MtCDH seems to be a universal electron donor for both bacterial and fungal LPMOs, indicating that their electron transfer mechanisms are similar.
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Affiliation(s)
- Jennifer S. M. Loose
- Department of ChemistryBiotechnology and Food Science, Norwegian University of Life SciencesNO‐1430 ÅsNorway
| | - Zarah Forsberg
- Department of ChemistryBiotechnology and Food Science, Norwegian University of Life SciencesNO‐1430 ÅsNorway
| | - Daniel Kracher
- Department of Food Science and Technology, Food Biotechnology LaboratoryUniversity of Natural Resources and Life SciencesViennaAustria
| | - Stefan Scheiblbrandner
- Department of Food Science and Technology, Food Biotechnology LaboratoryUniversity of Natural Resources and Life SciencesViennaAustria
| | - Roland Ludwig
- Department of Food Science and Technology, Food Biotechnology LaboratoryUniversity of Natural Resources and Life SciencesViennaAustria
| | - Vincent G. H. Eijsink
- Department of ChemistryBiotechnology and Food Science, Norwegian University of Life SciencesNO‐1430 ÅsNorway
| | - Gustav Vaaje‐Kolstad
- Department of ChemistryBiotechnology and Food Science, Norwegian University of Life SciencesNO‐1430 ÅsNorway
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7
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Characterization of the two Neurospora crassa cellobiose dehydrogenases and their connection to oxidative cellulose degradation. Appl Environ Microbiol 2012; 78:6161-71. [PMID: 22729546 DOI: 10.1128/aem.01503-12] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The genome of Neurospora crassa encodes two different cellobiose dehydrogenases (CDHs) with a sequence identity of only 53%. So far, only CDH IIA, which is induced during growth on cellulose and features a C-terminal carbohydrate binding module (CBM), was detected in the secretome of N. crassa and preliminarily characterized. CDH IIB is not significantly upregulated during growth on cellulosic material and lacks a CBM. Since CDH IIB could not be identified in the secretome, both CDHs were recombinantly produced in Pichia pastoris. With the cytochrome domain-dependent one-electron acceptor cytochrome c, CDH IIA has a narrower and more acidic pH optimum than CDH IIB. Interestingly, the catalytic efficiencies of both CDHs for carbohydrates are rather similar, but CDH IIA exhibits 4- to 5-times-higher apparent catalytic constants (k(cat) and K(m) values) than CDH IIB for most tested carbohydrates. A third major difference is the 65-mV-lower redox potential of the heme b cofactor in the cytochrome domain of CDH IIA than CDH IIB. To study the interaction with a member of the glycoside hydrolase 61 family, the copper-dependent polysaccharide monooxygenase GH61-3 (NCU02916) from N. crassa was expressed in P. pastoris. A pH-dependent electron transfer from both CDHs via their cytochrome domains to GH61-3 was observed. The different properties of CDH IIA and CDH IIB and their effect on interactions with GH61-3 are discussed in regard to the proposed in vivo function of the CDH/GH61 enzyme system in oxidative cellulose hydrolysis.
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Harreither W, Nicholls P, Sygmund C, Gorton L, Ludwig R. Investigation of the pH-dependent electron transfer mechanism of ascomycetous class II cellobiose dehydrogenases on electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:6714-23. [PMID: 22471986 DOI: 10.1021/la3005486] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cellobiose dehydrogenase (CDH) is capable of direct electron transfer (DET) on various carbon and thiol-modified gold electrodes. As a result, these systems have been utilized as biocatalyst in biosensors and biofuel cell anodes. Class I CDHs, from basidiomycetous fungi, are highly specific to cellulose or lactose, and DET is only observed at pH values below 5.5. To extend the applicability of CDH-based electrodes, the catalytic properties and the behavior on electrode surfaces of ascomycetous class II CDHs from Chaetomium attrobrunneum, Corynascus thermophilus, Dichomera saubinetii, Hypoxylon haematostroma, Neurospora crassa, and Stachybotrys bisbyi were investigated. We found that class II CDHs have diverse properties but generally show a lower substrate specificity than class I CDHs by converting also glucose and maltose. Intramolecular electron transfer (IET) and DET at neutral and alkaline pH were observed and elucidated by steady-state kinetics, pre-steady-state kinetics, and electrochemical measurements. The CDHs ability to interact with the electron acceptor cytochrome c and to communicate with electrode surfaces through DET at various pH conditions was used to classify the investigated enzymes. In combination with stopped-flow measurements, a model for the kinetics of the pH-dependent IET is developed. The efficient glucose turnover at neutral/alkaline pH makes some of these new CDHs potential candidates for glucose biosensors and biofuel cell anodes.
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Affiliation(s)
- Wolfgang Harreither
- Food Biotechnology Laboratory, Department of Food Sciences and Technology, BOKU - University of Natural Resources and Life Sciences , Muthgasse 18, A-1190 Vienna, Austria
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Ludwig R, Harreither W, Tasca F, Gorton L. Cellobiose Dehydrogenase: A Versatile Catalyst for Electrochemical Applications. Chemphyschem 2010; 11:2674-97. [DOI: 10.1002/cphc.201000216] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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10
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Mowat CG, Gazur B, Campbell LP, Chapman SK. Flavin-containing heme enzymes. Arch Biochem Biophys 2010; 493:37-52. [DOI: 10.1016/j.abb.2009.10.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 10/13/2009] [Accepted: 10/13/2009] [Indexed: 11/25/2022]
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11
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Shipovskov S, Ferapontova EE. Biocatalysis of theophylline oxidation by microbial theophylline oxidase in the presence of non-physiological electron acceptors. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420802456639] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Harreither W, Coman V, Ludwig R, Haltrich D, Gorton L. Investigation of Graphite Electrodes Modified with Cellobiose Dehydrogenase from the AscomyceteMyriococcum thermophilum. ELECTROANAL 2007. [DOI: 10.1002/elan.200603688] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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E Ferapontova E, Gorton L. Direct electrochemistry of heme multicofactor-containing enzymes on alkanethiol-modified gold electrodes. Bioelectrochemistry 2005; 66:55-63. [PMID: 15833703 DOI: 10.1016/j.bioelechem.2004.04.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2004] [Revised: 03/31/2004] [Accepted: 04/13/2004] [Indexed: 11/28/2022]
Abstract
Direct electrochemistry of heme multicofactor-containing enzymes, e.g., microbial theophylline oxidase (ThOx) and D-fructose dehydrogenase (FDH) from Gluconobacter industrius was studied on alkanethiol-modified gold electrodes and was compared with that of some previously studied complex heme enzymes, specifically, cellobiose dehydrogenase (CDH) and sulphite oxidase (SOx). The formal redox potentials for enzymes in direct electronic communication varied for ThOx from -112 to -101 mV (vs. Ag|AgCl), at pH 7.0, and for FDH from -158 to -89 mV, at pH 5.0 and pH 4.0, respectively, on differently charged alkanethiol layers. Direct and mediated by cytochrome c electrochemistry of FDH correlated with the existence of two active centres in the protein structure, i.e., the heme and the pyrroloquinoline quinone (PQQ) prosthetic groups. The effect of the alkanethiols of different polarity and charge on the surface properties of the gold electrodes necessary for adsorption and orientation of ThOx, FDH, CDH and SOx, favourable for the efficient electrode-enzyme electron transfer reaction, is discussed.
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Affiliation(s)
- Elena E Ferapontova
- Group of Bioinformatics, Weblab, IT Centre, Voskhod 26a, Novosibirsk 630102, Russia.
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14
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Igarashi K, Yoshida M, Matsumura H, Nakamura N, Ohno H, Samejima M, Nishino T. Electron transfer chain reaction of the extracellular flavocytochrome cellobiose dehydrogenase from the basidiomycete Phanerochaete chrysosporium. FEBS J 2005; 272:2869-77. [PMID: 15943818 DOI: 10.1111/j.1742-4658.2005.04707.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cellobiose dehydrogenase (CDH) is an extracellular flavocytochrome containing flavin and b-type heme, and plays a key role in cellulose degradation by filamentous fungi. To investigate intermolecular electron transfer from CDH to cytochrome c, Phe166, which is located in the cytochrome domain and approaches one of propionates of heme, was mutated to Tyr, and the thermodynamic and kinetic properties of the mutant (F166Y) were compared with those of the wild-type (WT) enzyme. The mid-point potential of heme in F166Y was measured by cyclic voltammetry, and was estimated to be 25 mV lower than that of WT at pH 4.0. Although presteady-state reduction of flavin was not affected by the mutation, the rate of subsequent electron transfer from flavin to heme was halved in F166Y. When WT or F166Y was reduced with cellobiose and then mixed with cytochrome c, heme re-oxidation and cytochrome c reduction occurred synchronously, suggesting that the initial electron is transferred from reduced heme to cytochrome c. Moreover, in both enzymes the observed rate of the initial phase of cytochrome c reduction was concentration dependent, whereas the second phase of cytochrome c reduction was dependent on the rate of electron transfer from flavin to heme, but not on the cytochrome c concentration. In addition, the electron transfer rate from flavin to heme was identical to the steady-state reduction rate of cytochrome c in both WT and F166Y. These results clearly indicate that the first and second electrons of two-electron-reduced CDH are both transferred via heme, and that the redox reaction of CDH involves an electron-transfer chain mechanism in cytochrome c reduction.
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Affiliation(s)
- Kiyohiko Igarashi
- Department of Biomaterials Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
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15
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Mason MG, Nicholls P, Divne C, Hallberg BM, Henriksson G, Wilson MT. The heme domain of cellobiose oxidoreductase: a one-electron reducing system. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1604:47-54. [PMID: 12686420 DOI: 10.1016/s0005-2728(03)00023-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Phanerochaete chrysosporium cellobiose oxidoreductase (CBOR) comprises two redox domains, one containing flavin adenine dinucleotide (FAD) and the other protoheme. It reduces both two-electron acceptors, including molecular oxygen, and one-electron acceptors, including transition metal complexes and cytochrome c. If the latter reacts with the flavin, the reduced heme b acts merely as a redox buffer, but if with the b heme, enzyme action involves a true electron transfer chain. Intact CBOR fully reduced with cellobiose, CBOR partially reduced by ascorbate, and isolated ascorbate-reduced heme domain, all transfer electrons at similar rates to cytochrome c. Reduction of cationic one-electron acceptors via the heme group supports an electron transfer chain model. Analogous reactions with natural one-electron acceptors can promote Fenton chemistry, which may explain evolutionary retention of the heme domain and the enzyme's unique character among secreted sugar dehydrogenases.
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Affiliation(s)
- Maria G Mason
- Department of Biological Sciences, University of Essex, Colchester, UK
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16
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Igarashi K, Momohara I, Nishino T, Samejima M. Kinetics of inter-domain electron transfer in flavocytochrome cellobiose dehydrogenase from the white-rot fungus Phanerochaete chrysosporium. Biochem J 2002; 365:521-6. [PMID: 11939907 PMCID: PMC1222687 DOI: 10.1042/bj20011809] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2001] [Revised: 03/18/2002] [Accepted: 04/08/2002] [Indexed: 11/17/2022]
Abstract
The pre-steady-state kinetics of inter-domain electron transfer in the extracellular flavocytochrome cellobiose dehydrogenase from Phanerochaete chrysosporium was studied using various values of pH and substrate concentration. Monitoring at the isosbestic point of each prosthetic group indicated that the reductive half-reactions of flavin and haem were biphasic and monophasic respectively. When the observed rates of the flavin and haem reactions were plotted against substrate concentration, the behaviour of the second phase of the flavin reduction was almost identical with that of haem reduction at all substrate concentrations and pH values tested, suggesting that the formation of flavin semiquinone and haem reduction involve the same electron transfer reaction. Although flavin reduction by cellobiose was observed in the range of pH 3.0-7.0, the velocity of the next electron transfer step decreased with increase of pH and was almost zero above pH 6.0. The second phase of flavin reduction and the haem reduction were inhibited similarly by high concentrations of the substrate, whereas the first phase of flavin reduction showed a hyperbolic relation to the cellobiose concentration. Increase in pH enhanced the substrate inhibition of haem reduction but not the initial flavin reduction. Moreover, the dissociation constant K(d) of flavin reduction and the substrate inhibition constant K(i) of haem reduction decreased similarly with an increase of pH. From these results, it is evident that binding of cellobiose to the active site inhibits electron transfer from flavin to haem.
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Affiliation(s)
- Kiyohiko Igarashi
- Department of Biomaterials Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
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17
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Mason MG, Wilson MT, Ball A, Nicholls P. Oxygen reduction by cellobiose oxidoreductase: the role of the haem group. FEBS Lett 2002; 518:29-32. [PMID: 11997012 DOI: 10.1016/s0014-5793(02)02633-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have used optical and electron paramagnetic spectroscopy to study the flavohaem enzyme cellobiose oxidoreductase (CBOR) from Phanerochaete chrysosporium. We have examined redox cycles of the enzyme in which the oxidation of cellobiose to cellobionolactone is coupled to the reduction of oxygen. During turnover flavin can reduce oxygen with one electron to produce superoxide or two electrons to produce hydrogen peroxide. Addition of superoxide dismutase significantly extended the time courses of these cycles, slowing the re-oxidation rate of both cofactors. Addition of catalase also affected the haem time course, but to a lesser extent. Experiments in which superoxide was generated in the reaction mixture showed that this radical greatly enhanced the rate of haem re-oxidation. From these results we propose a mechanism in which reactive oxygen species generation by CBOR flavin subsequently re-oxidises CBOR haem. We discuss this mechanism in relationship to the biological function of this enzyme, namely lignocellulose degradation.
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Affiliation(s)
- Maria G Mason
- Department of Biological Sciences, University of Essex, Wivenhoe Park, CO4 3SQ, Colchester, UK.
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18
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Scheller FW, Wollenberger U, Lei C, Jin W, Ge B, Lehmann C, Lisdat F, Fridman V. Bioelectrocatalysis by redox enzymes at modified electrodes. J Biotechnol 2002; 82:411-24. [PMID: 11996219 DOI: 10.1016/s1389-0352(01)00055-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Self-assembled monolayers of thiolated compounds are used as promoters for protein-electrode reactions. They provide an anchor group based on thiol chemisorptions and also a functional group for effective interaction with the protein. These interactions are often governed by electrostatic attraction. For example, for positively charged proteins, such as cytochrome c and the selenoprotein glutathione peroxidase, mercaptoalkanoic acids have been used. Clay modification of the electrode surface has been found to facilitate the heterogeneous electron transfer process for heme proteins, e.g. cytochrome c, cytochrome P450 and myoglobin. Interestingly, nucleic acids at carbon electrodes and thiol-modified double stranded oligonucleotides act as promoters of the redox communication to proteins, whereas the mechanism is still subject to controversy interpretations. By interacting the protein immobilised at the electrode with species in solution, signal chains have been constructed. The interaction can result in a simple co-ordination or redox reaction, depending on the nature of the reaction partners. For analytical purposes, e.g. biosensors, the electrochemical redox conversion of the immobilised protein is evaluated.
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Affiliation(s)
- Frieder W Scheller
- University of Potsdam, Institute of Biochemistry and Biology, Chair of Analytical Biochemistry, Golm, Germany.
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19
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Xu F, Golightly EJ, Duke KR, Lassen SF, Knusen B, Christensen S, Brown KM, Brown SH, Schülein M. Humicola insolens cellobiose dehydrogenase: cloning, redox chemistry, and "logic gate"-like dual functionality. Enzyme Microb Technol 2001; 28:744-753. [PMID: 11397454 DOI: 10.1016/s0141-0229(01)00319-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1Cellobiose dehydrogenase is a hemoflavoenzyme that catalyzes the sequential electron-transfer from an electron-donating substrate (e.g. cellobiose) to a flavin center, then to an electron-accepting substrate (e.g. quinone) either directly or via a heme center after an internal electron-transfer from the flavin to heme. We cloned the dehydrogenase from Humicola insolens, which encodes a protein of 761 amino acid residues containing an N-terminal heme domain and a C-terminal flavin domain, and studied how the catalyzed electron transfers are regulated. Based on the correlation between the rate and redox potential, we demonstrated that with a reduced flavin center, the enzyme, as a reductase, could export electron from its heme center by a "outer-sphere" mechanism. With the "resting" flavin center, however, the enzyme could have a peroxidase-like function and import electron to its heme center after a peroxidative activation. The dual functionality of its heme center makes the enzyme a molecular "logic gate", in which the electron flow through the heme center can be switched in direction by the redox state of the coupled flavin center.
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Affiliation(s)
- F Xu
- Novozymes Biotech, Inc., 1445 Drew Avenue, 95616, Davis, CA, USA
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20
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Lindgren A, Gorton L, Ruzgas T, Baminger U, Haltrich D, Schülein M. Direct electron transfer of cellobiose dehydrogenase from various biological origins at gold and graphite electrodes. J Electroanal Chem (Lausanne) 2001. [DOI: 10.1016/s0022-0728(00)00251-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Direct electron transfer between the heme of cellobiose dehydrogenase and thiol modified gold electrodes. J Electroanal Chem (Lausanne) 2000. [DOI: 10.1016/s0022-0728(00)00326-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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22
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Cameron MD, Aust SD. Kinetics and reactivity of the flavin and heme cofactors of cellobiose dehydrogenase from Phanerochaete chrysosporium. Biochemistry 2000; 39:13595-601. [PMID: 11063597 DOI: 10.1021/bi000862c] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The flavin cofactor within cellobiose dehydrogenase (CDH) was found to be responsible for the reduction of all electron acceptors tested. This includes cytochrome c, the reduction of which has been reported to be by the reduced heme of CDH. The heme group was shown to affect the reactivity and activation energy with respect to individual electron acceptors, but the heme group was not involved in the direct transfer of electrons to substrate. A complicated interaction was found to exist between the flavin and heme of cellobiose dehydrogenase. The addition of electron acceptors was shown to increase the rate of flavin reduction and the electron transfer rate between the flavin and heme. All electron acceptors tested appeared to be reduced by the flavin domain. The addition of ferric iron eliminated the flavin radical present in reduced CDH, as detected by low temperature ESR spectroscopy, while it increased the flavin radical ESR signal in the independent flavin domain, more commonly referred to as cellobiose:quinone oxidoreductase (CBQR). Conversely, no radical was detected with either CDH or CBQR upon the addition of methyl-1,4-benzoquinone. Similar reaction rates and activation energies were determined for methyl-1,4-benzoquinone with both CDH and CBQR, whereas the rate of iron reduction by CDH was five times higher than by CBQR, and its activation energy was 38 kJ/mol lower than that of CBQR. Oxygen, which may be reduced by either one or two electrons, was found to behave like a two-electron acceptor. Superoxide production was found only upon the inclusion of iron. Additionally, information is presented indicating that the site of substrate reduction may be in the cleft between the flavin and heme domains.
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Affiliation(s)
- M D Cameron
- Biotechnology Center, Utah State University, Logan, Utah 84322-4705, USA
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23
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Abstract
Cellobiose dehydrogenase (CDH) is an extracellular enzyme produced by various wood-degrading fungi. It oxidizes soluble cellodextrins, mannodextrins and lactose efficiently to their corresponding lactones by a ping-pong mechanism using a wide spectrum of electron acceptors including quinones, phenoxyradicals, Fe(3+), Cu(2+) and triiodide ion. Monosaccharides, maltose and molecular oxygen are poor substrates. CDH that adsorbs strongly and specifically to cellulose carries two prosthetic groups; namely, an FAD and a heme in two different domains that can be separated after limited proteolysis. The FAD-containing fragment carries all known catalytic and cellulose binding properties. One-electron acceptors, like ferricyanide, cytochrome c and phenoxy radicals, are, however, reduced more slowly by the FAD-fragment than by the intact enzyme, suggesting that the function of the heme group is to facilitate one-electron transfer. Non-heme forms of CDH have been found in the culture filtrate of some fungi (probably due to the action of fungal proteases) and were for a long time believed to represent a separate enzyme (cellobiose:quinone oxidoreductase, CBQ). The amino acid sequence of CDH has been determined and no significant homology with other proteins was detected for the heme domain. The FAD-domain sequence belongs to the GMC oxidoreductase family that includes, among others, Aspergillus niger glucose oxidase. The homology is most distinct in regions that correspond to the FAD-binding domain in glucose oxidase. A cellulose-binding domain of the fungal type is present in CDH from Myceliophtore thermophila (Sporotrichum thermophile), but in others an internal sequence rich in aromatic amino acid residues has been suggested to be responsible for the cellulose binding. The biological function of CDH is not fully understood, but recent results support a hydroxyl radical-generating mechanism whereby the radical can degrade and modify cellulose, hemicellulose and lignin. CDH has found technical use in highly selective amperometric biosensors and several other applications have been suggested.
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Affiliation(s)
- G Henriksson
- Department of Pulp and Paper Chemistry and Technology, Royal Institute of Technology, 100 44, Stockholm, Sweden.
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Henriksson G, Sild V, Szabó IJ, Pettersson G, Johansson G. Substrate specificity of cellobiose dehydrogenase from Phanerochaete chrysosporium. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1383:48-54. [PMID: 9546045 DOI: 10.1016/s0167-4838(97)00180-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Substrate structural mapping suggests that the catalytic site of cellobiose dehydrogenase from Phanerochaete chrysosporium forms a narrow cave with two hexose binding subsites. Kinetic data also show that beta-di or oligosaccharides are favored electron donors with respect to both KM and kcat. Surprisingly, thiocellobiose showed an even higher kcat than cellobiose, although the KM value was somewhat higher. The CDH was purified using an updated protocol.
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Affiliation(s)
- G Henriksson
- Department of Biochemistry, University of Uppsala, Sweden
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25
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Ander P, Marzullo L. Sugar oxidoreductases and veratryl alcohol oxidase as related to lignin degradation. J Biotechnol 1997; 53:115-31. [PMID: 9177041 DOI: 10.1016/s0168-1656(97)01680-5] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Properties of cellobiose:quinone oxidoreductase (CBQ), cellobiose dehydrogenase (CDH), glyoxal oxidase (GLOX), glucose oxidases and veratryl alcohol oxidase (VAO) are reviewed. There is strong evidence that CDH reduces quinones, phenoxy and cation radicals. Glucose oxidases (glucose 1-oxidase and pyranose 2-oxidase) and VAO have been less investigated but evidence for reduction of the above compounds is accumulating. Pyranose oxidase, glyoxal oxidase and VAO are very important for hydrogen peroxide production by white-rot fungi. CDH is only produced on cellulose or on wood, whereas pyranose oxidase and VAO are produced both on wood and on rich glucose media suggesting that the lignin degrading white-rot fungi may use different quinone and radical reducing enzymes to regulate lignin polymerization/depolymerization depending on the substrate and cultivation conditions. Intracellular quinone reductases are also produced. Whether brown-rot fungi in general produce CBQ/CDH or VAO is not clear. The Fe(III) reducing ability of both CDH and certain phenolate compounds agree with the rapid depolymerization of cellulose by brown-rot fungi. The interaction of Fe(III) reduction with the hydrogen peroxide producing system in white-rot and brown-rot fungi requires more investigation.
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Affiliation(s)
- P Ander
- Swedish University of Agricultural Sciences, Department of Forest Products, Uppsala, Sweden
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26
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Larsson T, Elmgren M, Lindquist SE, Tessema M, Gorton L, Henriksson G. Electron transfer between cellobiose dehydrogenase and graphite electrodes. Anal Chim Acta 1996. [DOI: 10.1016/0003-2670(96)00136-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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