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Yang J, Zhang X, Sun Q, Li R, Wang X, Zhao G, He X, Zheng F. Modulation of the catalytic activity and thermostability of a thermostable GH7 endoglucanase by engineering the key loop B3. Int J Biol Macromol 2023; 248:125945. [PMID: 37482151 DOI: 10.1016/j.ijbiomac.2023.125945] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023]
Abstract
The loop B3 of glycoside hydrolase family 7 (GH7) endoglucanases is confined into long and short types. TtCel7 is a thermophilic GH7 endoglucanase from Thermothelomyces thermophilus ATCC 42464 with a long loop B3. TtCel7 was distinct for the excellent thermostability (>30 % residual activity after 1-h incubation at 90 °C). The catalytic efficiency was reduced by removing the disulfide bond in loop B3 (C220A) and truncated the loop B3 (B3cut). However, B3cut exhibited improved thermostability, the remaining enzyme activity increased by 39 %-171 % compared toTtCel7 when treated at 70-90 °C for 1-h. Based on the analysis of molecular dynamics simulation, both loops B1 and A3 of B3cut swing toward the catalytic center, which contributed to the reduced cleft-space and increased structure-rigidity. Conversely, the deletion of disulfide bond resulted in a reduction of structural rigidity in C220A. Through structure-directed enzyme modulation, this study has identified two structural elements that are related to the catalysis and thermostability of TtCel7. The loop B3 of TtCel7 possibly stretches the catalytic pocket, thereby increases the openness of the catalytic tunnel and enhancing flexibility for efficient catalysis. Additionally, the disulfide bond within loop B3 serves to enhance structural stability and maintain a heightened level of activity.
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Affiliation(s)
- Junzhao Yang
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Xinrui Zhang
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Qingyang Sun
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Ruilin Li
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Xiaoyu Wang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Guozhu Zhao
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Xiangwei He
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Fei Zheng
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China.
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2
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Straightforward stereoselective synthesis of 1-thio-β-D-mannosides and 1-thio-β-L-rhamnosides. Tetrahedron Lett 2023. [DOI: 10.1016/j.tetlet.2023.154391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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3
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Abstract
Glycoscience assembles all the scientific disciplines involved in studying various molecules and macromolecules containing carbohydrates and complex glycans. Such an ensemble involves one of the most extensive sets of molecules in quantity and occurrence since they occur in all microorganisms and higher organisms. Once the compositions and sequences of these molecules are established, the determination of their three-dimensional structural and dynamical features is a step toward understanding the molecular basis underlying their properties and functions. The range of the relevant computational methods capable of addressing such issues is anchored by the specificity of stereoelectronic effects from quantum chemistry to mesoscale modeling throughout molecular dynamics and mechanics and coarse-grained and docking calculations. The Review leads the reader through the detailed presentations of the applications of computational modeling. The illustrations cover carbohydrate-carbohydrate interactions, glycolipids, and N- and O-linked glycans, emphasizing their role in SARS-CoV-2. The presentation continues with the structure of polysaccharides in solution and solid-state and lipopolysaccharides in membranes. The full range of protein-carbohydrate interactions is presented, as exemplified by carbohydrate-active enzymes, transporters, lectins, antibodies, and glycosaminoglycan binding proteins. A final section features a list of 150 tools and databases to help address the many issues of structural glycobioinformatics.
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Affiliation(s)
- Serge Perez
- Centre de Recherche sur les Macromolecules Vegetales, University of Grenoble-Alpes, Centre National de la Recherche Scientifique, Grenoble F-38041, France
| | - Olga Makshakova
- FRC Kazan Scientific Center of Russian Academy of Sciences, Kazan Institute of Biochemistry and Biophysics, Kazan 420111, Russia
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4
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Brander S, Tokin R, Ipsen JØ, Jensen PE, Hernández-Rollán C, Nørholm MHH, Lo Leggio L, Dupree P, Johansen KS. Scission of Glucosidic Bonds by a Lentinus similis Lytic Polysaccharide Monooxygenases Is Strictly Dependent on H2O2 while the Oxidation of Saccharide Products Depends on O2. ACS Catal 2021. [DOI: 10.1021/acscatal.1c04248] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Søren Brander
- Department of Geosciences and Natural Resource Management, Copenhagen University, DK-1958 Frederiksberg, Denmark
| | - Radina Tokin
- Department of Plant and Environmental Sciences, Copenhagen University, DK-1871 Frederiksberg, Denmark
| | - Johan Ø. Ipsen
- Department of Plant and Environmental Sciences, Copenhagen University, DK-1871 Frederiksberg, Denmark
| | - Poul Erik Jensen
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, DK-1958 Frederiksberg, Denmark
| | - Cristina Hernández-Rollán
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Morten H. H. Nørholm
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Paul Dupree
- Department of Biochemistry, University of Cambridge, CB2 1QW Cambridge, U.K
| | - Katja S. Johansen
- Department of Geosciences and Natural Resource Management, Copenhagen University, DK-1958 Frederiksberg, Denmark
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5
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Schröder SP, Offen WA, Males A, Jin Y, de Boer C, Enotarpi J, Marino L, van der Marel GA, Florea BI, Codée JDC, Overkleeft HS, Davies GJ. Development of Non-Hydrolysable Oligosaccharide Activity-Based Inactivators for Endoglycanases: A Case Study on α-1,6 Mannanases. Chemistry 2021; 27:9519-9523. [PMID: 33878235 PMCID: PMC8362039 DOI: 10.1002/chem.202101255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Indexed: 11/07/2022]
Abstract
There is a vast genomic resource for enzymes active on carbohydrates. Lagging far behind, however, are functional chemical tools for the rapid characterization of carbohydrate-active enzymes. Activity-based probes (ABPs) offer one chemical solution to these issues with ABPs based upon cyclophellitol epoxide and aziridine covalent and irreversible inhibitors representing a potent and widespread approach. Such inhibitors for enzymes active on polysaccharides are potentially limited by the requirement for several glycosidic bonds, themselves substrates for the enzyme targets. Here, it is shown that non-hydrolysable trisaccharide can be synthesized and applied even to enzymes with challenging subsite requirements. It was found that incorporation of carbasugar moieties, which was accomplished by cuprate-assisted regioselective trans-diaxial epoxide opening of carba-mannal synthesised for this purpose, yields inactivators that act as powerful activity-based inhibitors for α-1,6 endo-mannanases. 3-D structures at 1.35-1.47 Å resolutions confirm the design rationale and binding to the enzymatic nucleophile. Carbasugar oligosaccharide cyclophellitols offer a powerful new approach for the design of robust endoglycosidase inhibitors, while the synthesis procedures presented here should allow adaptation towards activity-based endoglycosidase probes as well as configurational isosteres targeting other endoglycosidase families.
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Affiliation(s)
- Sybrin P. Schröder
- Leiden Institute of ChemistryLeiden University Einsteinweg 552333CC LeidenThe Netherlands
| | - Wendy A. Offen
- Department of Chemistry, York Structural Biology LaboratoryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Alexandra Males
- Department of Chemistry, York Structural Biology LaboratoryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Yi Jin
- Department of Chemistry, York Structural Biology LaboratoryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Casper de Boer
- Leiden Institute of ChemistryLeiden University Einsteinweg 552333CC LeidenThe Netherlands
| | - Jacopo Enotarpi
- Leiden Institute of ChemistryLeiden University Einsteinweg 552333CC LeidenThe Netherlands
| | - Laura Marino
- Leiden Institute of ChemistryLeiden University Einsteinweg 552333CC LeidenThe Netherlands
| | | | - Bogdan I. Florea
- Leiden Institute of ChemistryLeiden University Einsteinweg 552333CC LeidenThe Netherlands
| | - Jeroen D. C. Codée
- Leiden Institute of ChemistryLeiden University Einsteinweg 552333CC LeidenThe Netherlands
| | - Herman S. Overkleeft
- Leiden Institute of ChemistryLeiden University Einsteinweg 552333CC LeidenThe Netherlands
| | - Gideon J. Davies
- Department of Chemistry, York Structural Biology LaboratoryUniversity of YorkHeslingtonYorkYO10 5DDUK
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6
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From lignocellulose to plastics: Knowledge transfer on the degradation approaches by fungi. Biotechnol Adv 2021; 50:107770. [PMID: 33989704 DOI: 10.1016/j.biotechadv.2021.107770] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/04/2021] [Accepted: 05/08/2021] [Indexed: 01/21/2023]
Abstract
In this review, we argue that there is much to be learned by transferring knowledge from research on lignocellulose degradation to that on plastic. Plastic waste accumulates in the environment to hazardous levels, because it is inherently recalcitrant to biological degradation. Plants evolved lignocellulose to be resistant to degradation, but with time, fungi became capable of utilising it for their nutrition. Examples of how fungal strategies to degrade lignocellulose could be insightful for plastic degradation include how fungi overcome the hydrophobicity of lignin (e.g. production of hydrophobins) and crystallinity of cellulose (e.g. oxidative approaches). In parallel, knowledge of the methods for understanding lignocellulose degradation could be insightful such as advanced microscopy, genomic and post-genomic approaches (e.g. gene expression analysis). The known limitations of biological lignocellulose degradation, such as the necessity for physiochemical pretreatments for biofuel production, can be predictive of potential restrictions of biological plastic degradation. Taking lessons from lignocellulose degradation for plastic degradation is also important for biosafety as engineered plastic-degrading fungi could also have increased plant biomass degrading capabilities. Even though plastics are significantly different from lignocellulose because they lack hydrolysable C-C or C-O bonds and therefore have higher recalcitrance, there are apparent similarities, e.g. both types of compounds are mixtures of hydrophobic polymers with amorphous and crystalline regions, and both require hydrolases and oxidoreductases for their degradation. Thus, many lessons could be learned from fungal lignocellulose degradation.
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7
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Molecular Basis for Substrate Recognition and Catalysis by a Marine Bacterial Laminarinase. Appl Environ Microbiol 2020; 86:AEM.01796-20. [PMID: 32917756 DOI: 10.1128/aem.01796-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 09/09/2020] [Indexed: 01/03/2023] Open
Abstract
Laminarin is an abundant algal polysaccharide that serves as carbon storage and fuel to meet the nutrition demands of heterotrophic microbes. Laminarin depolymerization catalyzed by microbial extracellular enzymes initiates remineralization, a key process in ocean biogeochemical cycles. Here, we described a glycoside hydrolase 16 (GH16) family laminarinase from a marine alga-associated Flavobacterium at the biochemical and structural levels. We found that the endolytic enzyme cleaved laminarin with a preference for β-1,3-glycoside linkages and showed transglycosylation activity across a broad range of acceptors. We also solved and compared high-resolution crystal structures of laminarinase in the apo form and in complex with β-1,3-tetrasaccharides, revealing an expanded catalytic cleft formed following substrate binding. Moreover, structure and mutagenesis studies identified multiple specific contacts between the enzyme and glucosyl residues essential for the substrate specificity for β-1,3-glucan. These results provide novel insights into the structural requirements for substrate binding and catalysis of GH16 family laminarinase, enriching our understanding of bacterial utilization of algal laminarin.IMPORTANCE Heterotrophic bacterial communities are key players in marine biogeochemical cycling due to their ability to remineralize organic carbon. Processing of complex organic matter requires heterotrophic bacteria to produce extracellular enzymes with precise specificity to depolymerize substrates to sizes sufficiently small for uptake. Thus, extracellular enzymatic hydrolysis initiates microbe-driven heterotrophic carbon cycling. In this study, based on biochemical and structural analyses, we revealed the depolymerization mechanism of β-1,3-glucan, a carbon reserve in algae, by laminarinase from an alga-associated marine Flavobacterium The findings provide new insights into the substrate recognition and catalysis of bacterial laminarinase and promote a better understanding of how extracellular enzymes are involved in organic matter cycling.
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8
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Cagnoni AJ, Primo ED, Klinke S, Cano ME, Giordano W, Mariño KV, Kovensky J, Goldbaum FA, Uhrig ML, Otero LH. Crystal structures of peanut lectin in the presence of synthetic β-N- and β-S-galactosides disclose evidence for the recognition of different glycomimetic ligands. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2020; 76:1080-1091. [PMID: 33135679 DOI: 10.1107/s2059798320012371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/08/2020] [Indexed: 11/11/2022]
Abstract
Carbohydrate-lectin interactions are involved in important cellular recognition processes, including viral and bacterial infections, inflammation and tumor metastasis. Hence, structural studies of lectin-synthetic glycan complexes are essential for understanding lectin-recognition processes and for the further design of promising chemotherapeutics that interfere with sugar-lectin interactions. Plant lectins are excellent models for the study of the molecular-recognition process. Among them, peanut lectin (PNA) is highly relevant in the field of glycobiology because of its specificity for β-galactosides, showing high affinity towards the Thomsen-Friedenreich antigen, a well known tumor-associated carbohydrate antigen. Given this specificity, PNA is one of the most frequently used molecular probes for the recognition of tumor cell-surface O-glycans. Thus, it has been extensively used in glycobiology for inhibition studies with a variety of β-galactoside and β-lactoside ligands. Here, crystal structures of PNA are reported in complex with six novel synthetic hydrolytically stable β-N- and β-S-galactosides. These complexes disclosed key molecular-binding interactions of the different sugars with PNA at the atomic level, revealing the roles of specific water molecules in protein-ligand recognition. Furthermore, binding-affinity studies by isothermal titration calorimetry showed dissociation-constant values in the micromolar range, as well as a positive multivalency effect in terms of affinity in the case of the divalent compounds. Taken together, this work provides a qualitative structural rationale for the upcoming synthesis of optimized glycoclusters designed for the study of lectin-mediated biological processes. The understanding of the recognition of β-N- and β-S-galactosides by PNA represents a benchmark in protein-carbohydrate interactions since they are novel synthetic ligands that do not belong to the family of O-linked glycosides.
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Affiliation(s)
- Alejandro J Cagnoni
- Laboratorio de Glicómica Funcional y Molecular, Instituto de Biología y Medicina Experimental, IBYME-CONICET, Vuelta de Obligado 2490, C1428ADN Buenos Aires, Argentina
| | - Emiliano D Primo
- Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, INBIAS-CONICET, Ruta Nacional 36 Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Sebastián Klinke
- Fundación Instituto Leloir, IIBBA-CONICET, Avenida Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - María E Cano
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, C1428EHA Buenos Aires, Argentina
| | - Walter Giordano
- Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, INBIAS-CONICET, Ruta Nacional 36 Km 601, 5800 Río Cuarto, Córdoba, Argentina
| | - Karina V Mariño
- Laboratorio de Glicómica Funcional y Molecular, Instituto de Biología y Medicina Experimental, IBYME-CONICET, Vuelta de Obligado 2490, C1428ADN Buenos Aires, Argentina
| | - José Kovensky
- Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources (LG2A)-CNRS UMR 7378, Université de Picardie Jules Verne, 33 Rue Saint Leu, 80039 Amiens CEDEX, France
| | - Fernando A Goldbaum
- Fundación Instituto Leloir, IIBBA-CONICET, Avenida Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - María Laura Uhrig
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, C1428EHA Buenos Aires, Argentina
| | - Lisandro H Otero
- Fundación Instituto Leloir, IIBBA-CONICET, Avenida Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
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9
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Sørlie M, Horn SJ, Vaaje-Kolstad G, Eijsink VG. Using chitosan to understand chitinases and the role of processivity in the degradation of recalcitrant polysaccharides. REACT FUNCT POLYM 2020. [DOI: 10.1016/j.reactfunctpolym.2020.104488] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Schiano‐di‐Cola C, Kołaczkowski B, Sørensen TH, Christensen SJ, Cavaleiro AM, Windahl MS, Borch K, Morth JP, Westh P. Structural and biochemical characterization of a family 7 highly thermostable endoglucanase from the fungusRasamsonia emersonii. FEBS J 2019; 287:2577-2596. [DOI: 10.1111/febs.15151] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/01/2019] [Accepted: 11/20/2019] [Indexed: 01/21/2023]
Affiliation(s)
| | | | - Trine Holst Sørensen
- Department of Science and Environment Roskilde University Denmark
- Novozymes A/S Lyngby Denmark
| | | | | | - Michael Skovbo Windahl
- Department of Science and Environment Roskilde University Denmark
- Novozymes A/S Lyngby Denmark
| | | | - Jens Preben Morth
- Department of Biotechnology and Biomedicine Technical University of Denmark Lyngby Denmark
| | - Peter Westh
- Department of Science and Environment Roskilde University Denmark
- Department of Biotechnology and Biomedicine Technical University of Denmark Lyngby Denmark
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11
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Structure and dynamics of Trichoderma harzianum Cel7B suggest molecular architecture adaptations required for a wide spectrum of activities on plant cell wall polysaccharides. Biochim Biophys Acta Gen Subj 2019; 1863:1015-1026. [DOI: 10.1016/j.bbagen.2019.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/04/2019] [Accepted: 03/18/2019] [Indexed: 11/19/2022]
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12
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Artola M, Hedberg C, Rowland RJ, Raich L, Kytidou K, Wu L, Schaaf A, Ferraz MJ, van der Marel GA, Codée JDC, Rovira C, Aerts JMFG, Davies GJ, Overkleeft HS. α-d-Gal-cyclophellitol cyclosulfamidate is a Michaelis complex analog that stabilizes therapeutic lysosomal α-galactosidase A in Fabry disease. Chem Sci 2019. [DOI: 10.1039/c9sc03342d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
α-d-Gal-cyclophellitol cyclosulfamidate is a new class of neutral, conformationally-constrained competitive glycosidase inhibitor that stabilizes α-gal A and prevents its degradation both in vitro and in cellulo by mimicry of the Michaelis complex conformation.
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13
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Enzyme Treatment at Different Stages of Textile Processing: A Review. Ind Biotechnol (New Rochelle N Y) 2018. [DOI: 10.1089/ind.2018.0018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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14
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Brandt SC, Ellinger B, van Nguyen T, Thi QD, van Nguyen G, Baschien C, Yurkov A, Hahnke RL, Schäfer W, Gand M. A unique fungal strain collection from Vietnam characterized for high performance degraders of bioecological important biopolymers and lipids. PLoS One 2018; 13:e0202695. [PMID: 30161149 PMCID: PMC6117010 DOI: 10.1371/journal.pone.0202695] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/07/2018] [Indexed: 11/18/2022] Open
Abstract
Fungal strains are abundantly used throughout all areas of biotechnology and many of them are adapted to degrade complex biopolymers like chitin or lignocellulose. We therefore assembled a collection of 295 fungi from nine different habitats in Vietnam, known for its rich biodiversity, and investigated their cellulase, chitinase, xylanase and lipase activity. The collection consists of 70 isolates from wood, 55 from soil, 44 from rice straw, 3 found on fruits, 24 from oil environments (butchery), 12 from hot springs, 47 from insects as well as 27 from shrimp shells and 13 strains from crab shells. These strains were cultivated and selected by growth differences to enrich phenotypes, resulting in 211 visually different fungi. DNA isolation of 183 isolates and phylogenetic analysis was performed and 164 species were identified. All were subjected to enzyme activity assays, yielding high activities for every investigated enzyme set. In general, enzyme activity corresponded with the environment of which the strain was isolated from. Therefore, highest cellulase activity strains were isolated from wood substrates, rice straw and soil and similar substrate effects were observed for chitinase and lipase activity. Xylanase activity was similarly distributed as cellulase activity, but substantial activity was also found from fungi isolated from insects and shrimp shells. Seven strains displayed significant activities against three of the four tested substrates, while three degraded all four investigated carbon sources. The collection will be an important source for further studies. Therefore representative strains were made available to the scientific community and deposited in the public collection of the Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig.
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Affiliation(s)
- Sophie C. Brandt
- Department of Molecular Phytopathology, University Hamburg, Hamburg, Germany
| | - Bernhard Ellinger
- Department ScreeningPort, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Hamburg, Germany
| | - Thuat van Nguyen
- Department of Molecular Phytopathology, University Hamburg, Hamburg, Germany
| | - Quyen Dinh Thi
- Institue of Biotechnology, Vietnam Academy of Science and Technology, Cau Giay, Hanoi, Vietnam
| | - Giang van Nguyen
- Faculty of Biotechnology, Vietnam National University of Agriculture, Trâu Quỳ, Gia Lâm, Hanoi, Vietnam
| | - Christiane Baschien
- Leibniz Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Andrey Yurkov
- Leibniz Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Richard L. Hahnke
- Leibniz Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Wilhelm Schäfer
- Department of Molecular Phytopathology, University Hamburg, Hamburg, Germany
| | - Martin Gand
- Department of Molecular Phytopathology, University Hamburg, Hamburg, Germany
- * E-mail:
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15
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Alonso-Gil S, Males A, Fernandes PZ, Williams SJ, Davies GJ, Rovira C. Computational Design of Experiment Unveils the Conformational Reaction Coordinate of GH125 α-Mannosidases. J Am Chem Soc 2017; 139:1085-1088. [DOI: 10.1021/jacs.6b11247] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Santiago Alonso-Gil
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain
| | - Alexandra Males
- York
Structural Biology Laboratory, Department of Chemistry, The University of York, YO10 5DD York, United Kingdom
| | - Pearl Z. Fernandes
- School
of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Spencer J. Williams
- School
of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Gideon J. Davies
- York
Structural Biology Laboratory, Department of Chemistry, The University of York, YO10 5DD York, United Kingdom
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
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16
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Belz T, Jin Y, Coines J, Rovira C, Davies GJ, Williams SJ. An atypical interaction explains the high-affinity of a non-hydrolyzable S-linked 1,6-α-mannanase inhibitor. Chem Commun (Camb) 2017; 53:9238-9241. [DOI: 10.1039/c7cc04977c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The non-hydrolyzable S-linked azasugar 1,6-α-mannobiosylthioisofagomine effects potent inhibition ofBacillus circulansfamily 76endo-1,6-α-mannanase through an atypical interaction involving the acid/base residue of the enzyme.
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Affiliation(s)
- Tyson Belz
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- University of Melbourne
- Parkville
- Australia
| | - Yi Jin
- York Structural Biology Laboratory
- Department of Chemistry
- University of York
- Heslington
- UK
| | - Joan Coines
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) & Institut de Química Teórica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) & Institut de Química Teórica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA)
| | - Gideon J. Davies
- York Structural Biology Laboratory
- Department of Chemistry
- University of York
- Heslington
- UK
| | - Spencer J. Williams
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- University of Melbourne
- Parkville
- Australia
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A building block approach to the synthesis of a family of S-linked α-1,6-oligomannosides. Carbohydr Res 2016; 429:38-47. [DOI: 10.1016/j.carres.2016.04.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 04/11/2016] [Accepted: 04/11/2016] [Indexed: 11/19/2022]
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Biochemical and Structural Characterizations of Two Dictyostelium Cellobiohydrolases from the Amoebozoa Kingdom Reveal a High Level of Conservation between Distant Phylogenetic Trees of Life. Appl Environ Microbiol 2016; 82:3395-409. [PMID: 27037126 DOI: 10.1128/aem.00163-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 03/25/2016] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED Glycoside hydrolase family 7 (GH7) cellobiohydrolases (CBHs) are enzymes commonly employed in plant cell wall degradation across eukaryotic kingdoms of life, as they provide significant hydrolytic potential in cellulose turnover. To date, many fungal GH7 CBHs have been examined, yet many questions regarding structure-activity relationships in these important natural and commercial enzymes remain. Here, we present the crystal structures and a biochemical analysis of two GH7 CBHs from social amoeba: Dictyostelium discoideum Cel7A (DdiCel7A) and Dictyostelium purpureum Cel7A (DpuCel7A). DdiCel7A and DpuCel7A natively consist of a catalytic domain and do not exhibit a carbohydrate-binding module (CBM). The structures of DdiCel7A and DpuCel7A, resolved to 2.1 Å and 2.7 Å, respectively, are homologous to those of other GH7 CBHs with an enclosed active-site tunnel. Two primary differences between the Dictyostelium CBHs and the archetypal model GH7 CBH, Trichoderma reesei Cel7A (TreCel7A), occur near the hydrolytic active site and the product-binding sites. To compare the activities of these enzymes with the activity of TreCel7A, the family 1 TreCel7A CBM and linker were added to the C terminus of each of the Dictyostelium enzymes, creating DdiCel7ACBM and DpuCel7ACBM, which were recombinantly expressed in T. reesei DdiCel7ACBM and DpuCel7ACBM hydrolyzed Avicel, pretreated corn stover, and phosphoric acid-swollen cellulose as efficiently as TreCel7A when hydrolysis was compared at their temperature optima. The Ki of cellobiose was significantly higher for DdiCel7ACBM and DpuCel7ACBM than for TreCel7A: 205, 130, and 29 μM, respectively. Taken together, the present study highlights the remarkable degree of conservation of the activity of these key natural and industrial enzymes across quite distant phylogenetic trees of life. IMPORTANCE GH7 CBHs are among the most important cellulolytic enzymes both in nature and for emerging industrial applications for cellulose breakdown. Understanding the diversity of these key industrial enzymes is critical to engineering them for higher levels of activity and greater stability. The present work demonstrates that two GH7 CBHs from social amoeba are surprisingly quite similar in structure and activity to the canonical GH7 CBH from the model biomass-degrading fungus T. reesei when tested under equivalent conditions (with added CBM-linker domains) on an industrially relevant substrate.
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Abstract
The enzyme-catalysed degradation of oligo and polysaccharides is of considerable interest in many fields ranging from the fundamental–understanding the intrinsic chemical beauty–through to the applied, including diverse practical applications in medicine and biotechnology. Carbohydrates are the most stereochemically-complex biopolymer, and myriad different natural polysaccharides have led to evolution of multifaceted enzyme consortia for their degradation. The glycosidic bonds that link sugar monomers are among the most chemically-stable, yet enzymatically-labile, bonds in the biosphere. That glycoside hydrolases can achieve a rate enhancement (kcat/kuncat) >1017-fold provides testament to their remarkable proficiency and the sophistication of their catalysis reaction mechanisms. The last two decades have seen significant advances in the discovery of new glycosidase sequences, sequence-based classification into families and clans, 3D structures and reaction mechanisms, providing new insights into enzymatic catalysis. New impetus to these studies has been provided by the challenges inherent in plant and microbial polysaccharide degradation, both in the context of environmentally-sustainable routes to foods and biofuels, and increasingly in human nutrition. Study of the reaction mechanism of glycoside hydrolases has also inspired the development of enzyme inhibitors, both as mechanistic probes and increasingly as therapeutic agents. We are on the cusp of a new era where we are learning how to dovetail powerful computational techniques with structural and kinetic data to provide an unprecedented view of conformational details of enzyme action.
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Hamid SBA, Islam MM, Das R. Cellulase biocatalysis: key influencing factors and mode of action. CELLULOSE 2015; 22:2157-2182. [DOI: 10.1007/s10570-015-0672-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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21
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Abstract
The article reviews the significant contributions to, and the present status of, applications of computational methods for the characterization and prediction of protein-carbohydrate interactions. After a presentation of the specific features of carbohydrate modeling, along with a brief description of the experimental data and general features of carbohydrate-protein interactions, the survey provides a thorough coverage of the available computational methods and tools. At the quantum-mechanical level, the use of both molecular orbitals and density-functional theory is critically assessed. These are followed by a presentation and critical evaluation of the applications of semiempirical and empirical methods: QM/MM, molecular dynamics, free-energy calculations, metadynamics, molecular robotics, and others. The usefulness of molecular docking in structural glycobiology is evaluated by considering recent docking- validation studies on a range of protein targets. The range of applications of these theoretical methods provides insights into the structural, energetic, and mechanistic facets that occur in the course of the recognition processes. Selected examples are provided to exemplify the usefulness and the present limitations of these computational methods in their ability to assist in elucidation of the structural basis underlying the diverse function and biological roles of carbohydrates in their dialogue with proteins. These test cases cover the field of both carbohydrate biosynthesis and glycosyltransferases, as well as glycoside hydrolases. The phenomenon of (macro)molecular recognition is illustrated for the interactions of carbohydrates with such proteins as lectins, monoclonal antibodies, GAG-binding proteins, porins, and viruses.
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Affiliation(s)
- Serge Pérez
- Department of Molecular Pharmacochemistry, CNRS, University Grenoble-Alpes, Grenoble, France.
| | - Igor Tvaroška
- Department of Chemistry, Slovak Academy of Sciences, Bratislava, Slovak Republic; Department of Chemistry, Faculty of Natural Sciences, Constantine The Philosopher University, Nitra, Slovak Republic.
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Abstract
SUMMARY Biomass is constructed of dense recalcitrant polymeric materials: proteins, lignin, and holocellulose, a fraction constituting fibrous cellulose wrapped in hemicellulose-pectin. Bacteria and fungi are abundant in soil and forest floors, actively recycling biomass mainly by extracting sugars from holocellulose degradation. Here we review the genome-wide contents of seven Aspergillus species and unravel hundreds of gene models encoding holocellulose-degrading enzymes. Numerous apparent gene duplications followed functional evolution, grouping similar genes into smaller coherent functional families according to specialized structural features, domain organization, biochemical activity, and genus genome distribution. Aspergilli contain about 37 cellulase gene models, clustered in two mechanistic categories: 27 hydrolyze and 10 oxidize glycosidic bonds. Within the oxidative enzymes, we found two cellobiose dehydrogenases that produce oxygen radicals utilized by eight lytic polysaccharide monooxygenases that oxidize glycosidic linkages, breaking crystalline cellulose chains and making them accessible to hydrolytic enzymes. Among the hydrolases, six cellobiohydrolases with a tunnel-like structural fold embrace single crystalline cellulose chains and cooperate at nonreducing or reducing end termini, splitting off cellobiose. Five endoglucanases group into four structural families and interact randomly and internally with cellulose through an open cleft catalytic domain, and finally, seven extracellular β-glucosidases cleave cellobiose and related oligomers into glucose. Aspergilli contain, on average, 30 hemicellulase and 7 accessory gene models, distributed among 9 distinct functional categories: the backbone-attacking enzymes xylanase, mannosidase, arabinase, and xyloglucanase, the short-side-chain-removing enzymes xylan α-1,2-glucuronidase, arabinofuranosidase, and xylosidase, and the accessory enzymes acetyl xylan and feruloyl esterases.
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23
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Song X, Wang Y, Zhang S, Yan S, Li T, Yao L. Characterization of the Dielectric Constant in the Trichoderma reesei Cel7B Active Site. J Chem Inf Model 2015; 55:1369-76. [PMID: 26114648 DOI: 10.1021/acs.jcim.5b00155] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An attempt is made to evaluate the dielectric constant of the Trichoderma reesei Cel7B active site. Through kinetic measurements, the pKa value of the catalytic acid E201 is determined. Mutations (away from E201) with net charge changes are introduced to perturb the E201 pKa. It is shown that the mutation with a +1 charge change (including G225R, G230R, and A335R) decreases the pKa of E201, whereas the mutation with a -1 charge change (including Q149E, A222D, G225D, and G230D) increases the pKa. This effect is consistent with the electrostatic interaction between the changed charge and the E201 side chain. The fitting of the experimental data yields an apparent dielectric constant of 25-80. Molecular dynamics simulations with explicit water molecules indicate that the high solvent accessibility of the active site contributes largely to the high dielectric constant. ONIOM calculations show that high dielectric constant benefits the catalysis through decreasing the energy of the transition state relative to that of the enzyme substrate complex.
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Affiliation(s)
- Xiangfei Song
- †Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266061, China
| | - Yefei Wang
- †Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266061, China
| | - Shujun Zhang
- †Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266061, China
| | - Shihai Yan
- ‡College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, Shandong, 266109, China
| | - Tong Li
- †Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266061, China
| | - Lishan Yao
- †Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266061, China
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Wheatley RW, Huber RE. An allolactose trapped at the lacZ β-galactosidase active site with its galactosyl moiety in a (4)H3 conformation provides insights into the formation, conformation, and stabilization of the transition state. Biochem Cell Biol 2015; 93:531-40. [PMID: 26291713 DOI: 10.1139/bcb-2015-0037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
When lactose was incubated with G794A-β-galactosidase (a variant with a "closed" active site loop that binds transition state analogs well) an allolactose was trapped with its Gal moiety in a (4)H3 conformation, similar to the oxocarbenium ion-like conformation expected of the transition state. The numerous interactions formed between the (4)H3 structure and β-galactosidase indicate that this structure is representative of the transition state. This conformation is also very similar to that of d-galactono-1,5-lactone, a good transition state analog. Evidence indicates that substrates take up the (4)H3 conformation during migration from the shallow to the deep mode. Steric forces utilizing His418 and other residues are important for positioning the O1 leaving group into a quasi-axial position. An electrostatic interaction between the O5 of the distorted Gal and Tyr503 as well as C-H-π bonds with Trp568 are also significant. Computational studies of the energy of sugar ring distortion show that the β-galactosidase reaction itinerary is driven by energetic considerations in utilization of a (4)H3 transition state with a novel (4)C1-(4)H3-(4)C1 conformation itinerary. To our knowledge, this is the first X-ray crystallographic structural demonstration that the transition state of a natural substrate of a glycosidase has a (4)H3 conformation.
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Affiliation(s)
- Robert W Wheatley
- Biochemistry Division, Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada.,Biochemistry Division, Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Reuben E Huber
- Biochemistry Division, Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada.,Biochemistry Division, Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada
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25
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Ardèvol A, Rovira C. Reaction Mechanisms in Carbohydrate-Active Enzymes: Glycoside Hydrolases and Glycosyltransferases. Insights from ab Initio Quantum Mechanics/Molecular Mechanics Dynamic Simulations. J Am Chem Soc 2015; 137:7528-47. [DOI: 10.1021/jacs.5b01156] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Albert Ardèvol
- Departament
de Química Orgànica and Institut de Química Teòrica
i Computacional (IQTCUB), Universitat de Barcelona, Martí
i Franquès 1, 08028 Barcelona, Spain
| | - Carme Rovira
- Departament
de Química Orgànica and Institut de Química Teòrica
i Computacional (IQTCUB), Universitat de Barcelona, Martí
i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08018 Barcelona, Spain
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Glycosynthesis in a waterworld: new insight into the molecular basis of transglycosylation in retaining glycoside hydrolases. Biochem J 2015; 467:17-35. [PMID: 25793417 DOI: 10.1042/bj20141412] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Carbohydrates are ubiquitous in Nature and play vital roles in many biological systems. Therefore the synthesis of carbohydrate-based compounds is of considerable interest for both research and commercial purposes. However, carbohydrates are challenging, due to the large number of sugar subunits and the multiple ways in which these can be linked together. Therefore, to tackle the challenge of glycosynthesis, chemists are increasingly turning their attention towards enzymes, which are exquisitely adapted to the intricacy of these biomolecules. In Nature, glycosidic linkages are mainly synthesized by Leloir glycosyltransferases, but can result from the action of non-Leloir transglycosylases or phosphorylases. Advantageously for chemists, non-Leloir transglycosylases are glycoside hydrolases, enzymes that are readily available and exhibit a wide range of substrate specificities. Nevertheless, non-Leloir transglycosylases are unusual glycoside hydrolases in as much that they efficiently catalyse the formation of glycosidic bonds, whereas most glycoside hydrolases favour the mechanistically related hydrolysis reaction. Unfortunately, because non-Leloir transglycosylases are almost indistinguishable from their hydrolytic counterparts, it is unclear how these enzymes overcome the ubiquity of water, thus avoiding the hydrolytic reaction. Without this knowledge, it is impossible to rationally design non-Leloir transglycosylases using the vast diversity of glycoside hydrolases as protein templates. In this critical review, a careful analysis of literature data describing non-Leloir transglycosylases and their relationship to glycoside hydrolase counterparts is used to clarify the state of the art knowledge and to establish a new rational basis for the engineering of glycoside hydrolases.
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Quantifying bond distortions in transient enzyme species by a combination of density functional theory calculations and time-resolved infrared difference spectroscopy. Implications for the mechanism of dephosphorylation of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA1a). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1036-43. [PMID: 25986318 DOI: 10.1016/j.bbabio.2015.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/22/2015] [Accepted: 05/09/2015] [Indexed: 12/26/2022]
Abstract
The sarcoplasmic Ca(2+)-ATPase (SERCA1a) forms two phosphoenzyme intermediates during Ca(2+) pumping. The second intermediate E2P hydrolyzes rapidly, which is essential for the rapid removal of Ca(2+) from the cytosol of muscle cells. The present work studies whether a weakening of the scissile PO bond in the E2P ground state facilitates dephosphorylation. To this end, the experimentally known vibrational spectrum of the E2P phosphate group was calculated with density functional theory (DFT) using structural models at two levels of structural complexity: (i) Models of acetyl phosphate in simple environments and (ii) ~150 atom models of the catalytic site. It was found that the enzyme environment distorts the structure of the phosphate group: one of the terminal PO bonds is shorter in the catalytic site indicating weaker interactions than in water. However, the bond that bridges phosphate and Asp351 is unaffected. This indicates that the scissile PO bond is not weakened by the enzyme environment of E2P. A second finding was that the catalytic site of the E2P state in aqueous solution appears to adopt a structure as in the crystals with BeF3(-), where the ATPase is in a non-reactive conformation. The reactant state of the dephosphorylation reaction differs from the E2P ground state: Glu183 faces Asp351 and positions the attacking water molecule. This state has a 0.04Å longer, and thus weaker, bridging PO bond. The reactant state is not detected in our experiments, indicating that its energy is at least 1kcal/mol higher than that of the E2P ground state.
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28
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Iglesias-Fernández J, Raich L, Ardèvol A, Rovira C. The complete conformational free energy landscape of β-xylose reveals a two-fold catalytic itinerary for β-xylanases. Chem Sci 2015; 6:1167-1177. [PMID: 29560204 PMCID: PMC5811086 DOI: 10.1039/c4sc02240h] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 10/27/2014] [Indexed: 01/28/2023] Open
Abstract
Unraveling the conformational catalytic itinerary of glycoside hydrolases (GHs) is a growing topic of interest in glycobiology, with major impact in the design of GH inhibitors. β-xylanases are responsible for the hydrolysis of glycosidic bonds in β-xylans, a group of hemicelluloses of high biotechnological interest that are found in plant cell walls. The precise conformations followed by the substrate during catalysis in β-xylanases have not been unambiguously resolved, with three different pathways being proposed from structural analyses. In this work, we compute the conformational free energy landscape (FEL) of β-xylose to predict the most likely catalytic itineraries followed by β-xylanases. The calculations are performed by means of ab initio metadynamics, using the Cremer-Pople puckering coordinates as collective variables. The computed FEL supports only two of the previously proposed itineraries, 2SO → [2,5B]ǂ → 5S1 and 1S3 → [4H3]ǂ → 4C1, which clearly appear in low energy regions of the FEL. Consistently, 2SO and 1S3 are conformations preactivated for catalysis in terms of free energy/anomeric charge and bond distances. The results however exclude the OE → [OS2]ǂ → B2,5 itinerary that has been recently proposed for a family 11 xylanase. Classical and ab initio QM/MM molecular dynamics simulations reveal that, in this case, the observed OE conformation has been enforced by enzyme mutation. These results add a word of caution on using modified enzymes to inform on catalytic conformational itineraries of glycoside hydrolases.
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Affiliation(s)
- Javier Iglesias-Fernández
- Departament de Química Orgànica and Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , Martí i Franquès 1 , 08028 Barcelona , Spain .
| | - Lluís Raich
- Departament de Química Orgànica and Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , Martí i Franquès 1 , 08028 Barcelona , Spain .
| | - Albert Ardèvol
- Department of Chemistry and Applied Biosciences , ETH Zürich , USI Campus , 6900 Lugano , Switzerland
| | - Carme Rovira
- Departament de Química Orgànica and Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , Martí i Franquès 1 , 08028 Barcelona , Spain .
- Institució Catalana de Recerca i Estudis Avançats (ICREA) , Passeig Lluís Companys , 23 , 08018 Barcelona , Spain
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Payne CM, Knott BC, Mayes HB, Hansson H, Himmel ME, Sandgren M, Ståhlberg J, Beckham GT. Fungal Cellulases. Chem Rev 2015; 115:1308-448. [DOI: 10.1021/cr500351c] [Citation(s) in RCA: 533] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Christina M. Payne
- Department
of Chemical and Materials Engineering and Center for Computational
Sciences, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, Kentucky 40506, United States
| | - Brandon C. Knott
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Heather B. Mayes
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Henrik Hansson
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Michael E. Himmel
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mats Sandgren
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Jerry Ståhlberg
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Gregg T. Beckham
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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Thiery E, Reniers J, Wouters J, Vincent SP. Stereoselective Synthesis of Boat-Locked Glycosides Designed as Glycosyl Hydrolase Conformational Probes. European J Org Chem 2015. [DOI: 10.1002/ejoc.201403363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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31
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Govender KK, Naidoo KJ. Evaluating AM1/d-CB1 for Chemical Glycobiology QM/MM Simulations. J Chem Theory Comput 2014; 10:4708-17. [DOI: 10.1021/ct500373p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Krishna K. Govender
- Scientific Computing
Research Unit and Department
of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kevin J. Naidoo
- Scientific Computing
Research Unit and Department
of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
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32
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Govender K, Gao J, Naidoo KJ. AM1/d-CB1: A Semiempirical Model for QM/MM Simulations of Chemical Glycobiology Systems. J Chem Theory Comput 2014; 10:4694-4707. [PMID: 26120288 DOI: 10.1021/ct500372s] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A semiempirical method based on the AM1/d Hamiltonian is introduced to model chemical glycobiological systems. We included in the parameter training set glycans and the chemical environment often found about them in glycoenzymes. Starting with RM1 and AM1/d-PhoT models we optimized H, C, N, O, and P atomic parameters targeting the best performing molecular properties that contribute to enzyme catalyzed glycan reaction mechanisms. The training set comprising glycans, amino acids, phosphates and small organic model systems was used to derive parameters that reproduce experimental data or high-level density functional results for carbohydrate, phosphate and amino acid heats of formation, amino acid proton affinities, amino acid and monosaccharide dipole moments, amino acid ionization potentials, water-phosphate interaction energies, and carbohydrate ring pucker relaxation times. The result is the AM1/d-Chemical Biology 1 or AM1/d-CB1 model that is considerably more accurate than existing NDDO methods modeling carbohydrates and the amino acids often present in the catalytic domains of glycoenzymes as well as the binding sites of lectins. Moreover, AM1/d-CB1 computed proton affinities, dipole moments, ionization potentials and heats of formation for transition state puckered carbohydrate ring conformations, observed along glycoenzyme catalyzed reaction paths, are close to values computed using DFT M06-2X. AM1/d-CB1 provides a platform from which to accurately model reactions important in chemical glycobiology.
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Affiliation(s)
- Krishna Govender
- Scientific Computing Research Unit, University of Cape Town, Rondebosch 7701, South Africa ; Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Jiali Gao
- State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun, Jilin Province 130012, China ; Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Kevin J Naidoo
- Scientific Computing Research Unit, University of Cape Town, Rondebosch 7701, South Africa ; Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
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Wang K, Luo H, Shi P, Huang H, Bai Y, Yao B. A highly-active endo-1,3-1,4-β-glucanase from thermophilic Talaromyces emersonii CBS394.64 with application potential in the brewing and feed industries. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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34
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Knott BC, Crowley MF, Himmel ME, Ståhlberg J, Beckham GT. Carbohydrate-protein interactions that drive processive polysaccharide translocation in enzymes revealed from a computational study of cellobiohydrolase processivity. J Am Chem Soc 2014; 136:8810-9. [PMID: 24869982 DOI: 10.1021/ja504074g] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Translocation of carbohydrate polymers through protein tunnels and clefts is a ubiquitous biochemical phenomenon in proteins such as polysaccharide synthases, glycoside hydrolases, and carbohydrate-binding modules. Although static snapshots of carbohydrate polymer binding in proteins have long been studied via crystallography and spectroscopy, the molecular details of polysaccharide chain processivity have not been elucidated. Here, we employ simulation to examine how a cellulose chain translocates by a disaccharide unit during the processive cycle of a glycoside hydrolase family 7 cellobiohydrolase. Our results demonstrate that these biologically and industrially important enzymes employ a two-step mechanism for chain threading to form a Michaelis complex and that the free energy barrier to chain threading is significantly lower than the hydrolysis barrier. Taken with previous studies, our findings suggest that the rate-limiting step in enzymatic cellulose degradation is the glycosylation reaction, not chain processivity. Based on the simulations, we find that strong electrostatic interactions with polar residues that are conserved in GH7 cellobiohydrolases, but not in GH7 endoglucanases, at the leading glucosyl ring provide the thermodynamic driving force for polysaccharide chain translocation. Also, we consider the role of aromatic-carbohydrate interactions, which are widespread in carbohydrate-active enzymes and have long been associated with processivity. Our analysis suggests that the primary role for these aromatic residues is to provide tunnel shape and guide the carbohydrate chain to the active site. More broadly, this work elucidates the role of common protein motifs found in carbohydrate-active enzymes that synthesize or depolymerize polysaccharides by chain translocation mechanisms coupled to catalysis.
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Affiliation(s)
- Brandon C Knott
- National Bioenergy Center and ‡Biosciences Center, National Renewable Energy Laboratory , Golden, Colorado 80401, United States
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35
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V. Sambasivarao S, M. Granum D, Wang H, Mark Maupin C. Identifying the Enzymatic Mode of Action for Cellulase Enzymes by Means of Docking Calculations and a Machine Learning Algorithm. AIMS MOLECULAR SCIENCE 2014. [DOI: 10.3934/molsci.2014.1.59] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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36
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Hill CH, Graham SC, Read RJ, Deane JE. Structural snapshots illustrate the catalytic cycle of β-galactocerebrosidase, the defective enzyme in Krabbe disease. Proc Natl Acad Sci U S A 2013; 110:20479-84. [PMID: 24297913 PMCID: PMC3870757 DOI: 10.1073/pnas.1311990110] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glycosphingolipids are ubiquitous components of mammalian cell membranes, and defects in their catabolism by lysosomal enzymes cause a diverse array of diseases. Deficiencies in the enzyme β-galactocerebrosidase (GALC) cause Krabbe disease, a devastating genetic disorder characterized by widespread demyelination and rapid, fatal neurodegeneration. Here, we present a series of high-resolution crystal structures that illustrate key steps in the catalytic cycle of GALC. We have captured a snapshot of the short-lived enzyme-substrate complex illustrating how wild-type GALC binds a bona fide substrate. We have extensively characterized the enzyme kinetics of GALC with this substrate and shown that the enzyme is active in crystallo by determining the structure of the enzyme-product complex following extended soaking of the crystals with this same substrate. We have also determined the structure of a covalent intermediate that, together with the enzyme-substrate and enzyme-product complexes, reveals conformational changes accompanying the catalytic steps and provides key mechanistic insights, laying the foundation for future design of pharmacological chaperones.
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Affiliation(s)
- Chris H. Hill
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom; and
| | - Stephen C. Graham
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - Randy J. Read
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom; and
| | - Janet E. Deane
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom; and
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37
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Knott BC, Haddad Momeni M, Crowley MF, Mackenzie LF, Götz AW, Sandgren M, Withers SG, Ståhlberg J, Beckham GT. The Mechanism of Cellulose Hydrolysis by a Two-Step, Retaining Cellobiohydrolase Elucidated by Structural and Transition Path Sampling Studies. J Am Chem Soc 2013; 136:321-9. [DOI: 10.1021/ja410291u] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
| | - Majid Haddad Momeni
- Department
of Molecular Biology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
| | | | - Lloyd F. Mackenzie
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Andreas W. Götz
- San
Diego Supercomputer Center, University of California San Diego, La Jolla, California 92093, United States
| | - Mats Sandgren
- Department
of Molecular Biology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
| | - Stephen G. Withers
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Jerry Ståhlberg
- Department
of Molecular Biology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
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38
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Labourel A, Jam M, Jeudy A, Hehemann JH, Czjzek M, Michel G. The β-glucanase ZgLamA from Zobellia galactanivorans evolved a bent active site adapted for efficient degradation of algal laminarin. J Biol Chem 2013; 289:2027-42. [PMID: 24337571 DOI: 10.1074/jbc.m113.538843] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Laminarinase is commonly used to describe β-1,3-glucanases widespread throughout Archaea, bacteria, and several eukaryotic lineages. Some β-1,3-glucanases have already been structurally and biochemically characterized, but very few from organisms that are in contact with genuine laminarin, the storage polysaccharide of brown algae. Here we report the heterologous expression and subsequent biochemical and structural characterization of ZgLamAGH16 from Zobellia galactanivorans, the first GH16 laminarinase from a marine bacterium associated with seaweeds. ZgLamAGH16 contains a unique additional loop, compared with other GH16 laminarinases, which is composed of 17 amino acids and gives a bent shape to the active site cleft of the enzyme. This particular topology is perfectly adapted to the U-shaped conformation of laminarin chains in solution and thus explains the predominant specificity of ZgLamAGH16 for this substrate. The three-dimensional structure of the enzyme and two enzyme-substrate complexes, one with laminaritetraose and the other with a trisaccharide of 1,3-1,4-β-d-glucan, have been determined at 1.5, 1.35, and 1.13 Å resolution, respectively. The structural comparison of substrate recognition pattern between these complexes allows the proposition that ZgLamAGH16 likely diverged from an ancestral broad specificity GH16 β-glucanase and evolved toward a bent active site topology adapted to efficient degradation of algal laminarin.
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Affiliation(s)
- Aurore Labourel
- From Sorbonne Universités, UPMC Université Paris 06, UMR 7139, Marine Plants and Biomolecules, Station Biologique de Roscoff, F-29682 Roscoff, Bretagne, France and
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39
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Park I, Lee H, Cha J. Glycoconjugates synthesized via transglycosylation by a thermostable α-glucosidase from Thermoplasma acidophilum and its glycosynthase mutant. Biotechnol Lett 2013; 36:789-96. [DOI: 10.1007/s10529-013-1412-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 11/12/2013] [Indexed: 10/25/2022]
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40
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Zhang Y, Yan S, Yao L. A Mechanistic Study of Trichoderma reesei Cel7B Catalyzed Glycosidic Bond Cleavage. J Phys Chem B 2013; 117:8714-22. [DOI: 10.1021/jp403999s] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Yu Zhang
- Laboratory
of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266061, China
| | - Shihai Yan
- Laboratory
of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266061, China
| | - Lishan Yao
- Laboratory
of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266061, China
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41
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Ouairy C, Cresteil T, Delpech B, Crich D. Synthesis and evaluation of 3-deoxy and 3-deoxy-3-fluoro derivatives of gluco- and manno-configured tetrahydropyridoimidazole glycosidase inhibitors. Carbohydr Res 2013; 377:35-43. [PMID: 23792222 DOI: 10.1016/j.carres.2013.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 05/11/2013] [Accepted: 05/13/2013] [Indexed: 12/01/2022]
Abstract
Three tetrahydropyridoimidazole-type glycosidase inhibitors have been synthesized with the 3-deoxy ribo- and arabino-, and 3-deoxy-3-fluoro gluco-configurations and two of them screened for activity against α- and β-gluco- and mannosidase enzymes. Only one substance, the 3-deoxy-3-fluoro-derivative of the gluco-configured tetrahydropyridoimidazole was found to have any activity against a single enzyme, sweet almond β-glucosidase, and even then at a level 100-fold lower than that of the corresponding simple gluco-configured tetrahydropyridoimidazole thereby underlining the importance of the 3-hydroxy group in the key substrate-enzyme interactions.
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Affiliation(s)
- Cécile Ouairy
- Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette, France
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42
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Bacik JP, Whitworth GE, Stubbs KA, Vocadlo DJ, Mark BL. Active site plasticity within the glycoside hydrolase NagZ underlies a dynamic mechanism of substrate distortion. ACTA ACUST UNITED AC 2013. [PMID: 23177201 DOI: 10.1016/j.chembiol.2012.09.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
NagZ is a glycoside hydrolase that participates in peptidoglycan (PG) recycling by removing β-N-acetylglucosamine from PG fragments that are excised from the bacterial cell wall during growth. Notably, the products formed by NagZ, 1,6-anhydroMurNAc-peptides, activate β-lactam resistance in many Gram-negative bacteria, making this enzyme of interest as a potential therapeutic target. Crystal structure determinations of NagZ from Salmonella typhimurium and Bacillus subtilis in complex with natural substrate, trapped as a glycosyl-enzyme intermediate, and bound to product, define the reaction coordinate of the NagZ family of enzymes. The structures, combined with kinetic studies, reveal an uncommon degree of structural plasticity within the active site of a glycoside hydrolase, and unveil how NagZ drives substrate distortion using a highly mobile loop that contains a conserved histidine that has been proposed as the general acid/base.
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Affiliation(s)
- John-Paul Bacik
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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43
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Bu L, Crowley MF, Himmel ME, Beckham GT. Computational investigation of the pH dependence of loop flexibility and catalytic function in glycoside hydrolases. J Biol Chem 2013; 288:12175-86. [PMID: 23504310 DOI: 10.1074/jbc.m113.462465] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellulase enzymes cleave glycosidic bonds in cellulose to produce cellobiose via either retaining or inverting hydrolysis mechanisms, which are significantly pH-dependent. Many fungal cellulases function optimally at pH ~5, and their activities decrease dramatically at higher or lower pH. To understand the molecular-level implications of pH in cellulase structure, we use a hybrid, solvent-based, constant pH molecular dynamics method combined with pH-based replica exchange to determine the pK(a) values of titratable residues of a glycoside hydrolase (GH) family 6 cellobiohydrolase (Cel6A) and a GH family 7 cellobiohydrolase (Cel7A) from the fungus Hypocrea jecorina. For both enzymes, we demonstrate that a bound substrate significantly affects the pKa values of the acid residues at the catalytic center. The calculated pK(a) values of catalytic residues confirm their proposed roles from structural studies and are consistent with the experimentally measured apparent pKa values. Additionally, GHs are known to impart a strained pucker conformation in carbohydrate substrates in active sites for catalysis, and results from free energy calculations combined with constant pH molecular dynamics suggest that the correct ring pucker is stable near the optimal pH for both Cel6A and Cel7A. Much longer molecular dynamics simulations of Cel6A and Cel7A with fixed protonation states based on the calculated pK(a) values suggest that pH affects the flexibility of tunnel loops, which likely affects processivity and substrate complexation. Taken together, this work demonstrates several molecular-level effects of pH on GH enzymes important for cellulose turnover in the biosphere and relevant to biomass conversion processes.
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Affiliation(s)
- Lintao Bu
- National Bioenergy Center, Colorado School of Mines, Golden, Colorado 80401, USA.
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44
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Momeni MH, Payne CM, Hansson H, Mikkelsen NE, Svedberg J, Engström Å, Sandgren M, Beckham GT, Ståhlberg J. Structural, biochemical, and computational characterization of the glycoside hydrolase family 7 cellobiohydrolase of the tree-killing fungus Heterobasidion irregulare. J Biol Chem 2013; 288:5861-72. [PMID: 23303184 DOI: 10.1074/jbc.m112.440891] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Root rot fungi of the Heterobasidion annosum complex are the most damaging pathogens in temperate forests, and the recently sequenced Heterobasidion irregulare genome revealed over 280 carbohydrate-active enzymes. Here, H. irregulare was grown on biomass, and the most abundant protein in the culture filtrate was identified as the only family 7 glycoside hydrolase in the genome, which consists of a single catalytic domain, lacking a linker and carbohydrate-binding module. The enzyme, HirCel7A, was characterized biochemically to determine the optimal conditions for activity. HirCel7A was crystallized and the structure, refined at 1.7 Å resolution, confirms that HirCel7A is a cellobiohydrolase rather than an endoglucanase, with a cellulose-binding tunnel that is more closed than Phanerochaete chrysosporium Cel7D and more open than Hypocrea jecorina Cel7A, suggesting intermediate enzyme properties. Molecular simulations were conducted to ascertain differences in enzyme-ligand interactions, ligand solvation, and loop flexibility between the family 7 glycoside hydrolase cellobiohydrolases from H. irregulare, H. jecorina, and P. chrysosporium. The structural comparisons and simulations suggest significant differences in enzyme-ligand interactions at the tunnel entrance in the -7 to -4 binding sites and suggest that a tyrosine residue at the tunnel entrance of HirCel7A may serve as an additional ligand-binding site. Additionally, the loops over the active site in H. jecorina Cel7A are more closed than loops in the other two enzymes, which has implications for the degree of processivity, endo-initiation, and substrate dissociation. Overall, this study highlights molecular level features important to understanding this biologically and industrially important family of glycoside hydrolases.
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Affiliation(s)
- Majid Haddad Momeni
- Department of Molecular Biology, Swedish University of Agricultural Sciences, SE-751 24 Uppsala, Sweden
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45
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Walvoort MTC, van der Marel GA, Overkleeft HS, Codée JDC. On the reactivity and selectivity of donor glycosides in glycochemistry and glycobiology: trapped covalent intermediates. Chem Sci 2013. [DOI: 10.1039/c2sc21610h] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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46
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Gupta V, Prasanna R, Chaudhary V, Nain L. Biochemical, structural and functional characterization of two novel antifungal endoglucanases from Anabaena laxa. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2012. [DOI: 10.1016/j.bcab.2012.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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47
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The crystallization and structural analysis of cellulases (and other glycoside hydrolases): strategies and tactics. Methods Enzymol 2012; 510:141-68. [PMID: 22608725 DOI: 10.1016/b978-0-12-415931-0.00008-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The three-dimensional (3-D) structures of cellulases, and other glycoside hydrolases, are a central feature of research in carbohydrate chemistry and biochemistry. 3-D structure is used to inform protein engineering campaigns, both academic and industrial, which are typically used to improve the stability or activity of an enzyme. Examples of classical protein engineering goals include higher thermal stability, reduced metal-ion dependency, detergent and protease resistance, decreased product inhibition, and altered specificity. 3-D structure may also be used to interpret the behavior of enzyme variants that are derived from screening or random mutagenesis approaches, with a view to establishing an iterative design process. In other areas, 3-D structure is used as one of the many tools to probe enzymatic catalysis, typically dovetailing with physical organic chemistry approaches to provide complete reaction mechanisms for enzymes by visualizing catalytic site interactions at different stages of the reaction. Such mechanistic insight is not only fundamentally important, impacting on inhibitor and drug design approaches with ramifications way beyond cellulose hydrolysis, but also provides the framework for the design of enzyme variants to use as biocatalysts for the synthesis of bespoke oligosaccharides. Here we review some of the strategies and tactics that may be applied to the X-ray structure solution of cellulases (and other carbohydrate-active enzymes). The general approach is first to decide why you are doing the work, then to establish correct domain boundaries for truncated constructs (typically the catalytic domain only), and finally to pursue crystallization of pure, homogeneous, and monodisperse protein with appropriate ligand and additive combinations. Cellulase-specific strategies are important for the delineation of domain boundaries, while glycoside hydrolases generally also present challenges and opportunities for the selection and optimization of ligands to both aid crystallization, and also provide structural and mechanistic insight. As the many roles for plant cell wall degrading enzymes increase, so does the need for rapid high-quality structure determination to provide a sound structural foundation for understanding mechanism and specificity, and for future protein engineering strategies.
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48
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DeMarco ML. Three-Dimensional Structure of Glycolipids in Biological Membranes. Biochemistry 2012; 51:5725-32. [DOI: 10.1021/bi3003633] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Mari L. DeMarco
- Division of Laboratory
and Genomic Medicine, Washington University School of Medicine, 660 South
Euclid Avenue, St. Louis, Missouri 63110, United States
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49
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Hehemann JH, Smyth L, Yadav A, Vocadlo DJ, Boraston AB. Analysis of keystone enzyme in Agar hydrolysis provides insight into the degradation (of a polysaccharide from) red seaweeds. J Biol Chem 2012; 287:13985-95. [PMID: 22393053 DOI: 10.1074/jbc.m112.345645] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Agars are abundant polysaccharides from marine red algae, and their chemical structure consists of alternating D-galactose and 3,6-anhydro-L-galactose residues, the latter of which are presumed to make the polymer recalcitrant to degradation by most terrestrial bacteria. Here we study a family 117 glycoside hydrolase (BpGH117) encoded within a recently discovered locus from the human gut bacterium Bacteroides plebeius. Consistent with this locus being involved in agarocolloid degradation, we show that BpGH117 is an exo-acting 3,6-anhydro-α-(1,3)-L-galactosidase that removes the 3,6-anhydrogalactose from the non-reducing end of neoagaro-oligosaccharides. A Michaelis complex of BpGH117 with neoagarobiose reveals the distortion of the constrained 3,6-anhydro-L-galactose into a conformation that favors catalysis. Furthermore, this complex, supported by analysis of site-directed mutants, provides evidence for an organization of the active site and positioning of the catalytic residues that are consistent with an inverting mechanism of catalysis and suggests that a histidine residue acts as the general acid. This latter feature differs from the vast majority of glycoside hydrolases, which use a carboxylic acid, highlighting the alternative strategies that enzymes may utilize in catalyzing the cleavage of glycosidic bonds.
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Affiliation(s)
- Jan-Hendrik Hehemann
- Department of Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, British Columbia V8W 3P6, Canada
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50
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Vidadala SR, Thadke SA, Hotha S, Kashyap S. Synthesis of Thioglycosides from Propargyl Glycosides Exploiting Alkynophilic Gold Catalyst. J Carbohydr Chem 2012. [DOI: 10.1080/07328303.2011.652789] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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