51
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Morrill J, Kulcinskaja E, Sulewska AM, Lahtinen S, Stålbrand H, Svensson B, Abou Hachem M. The GH5 1,4-β-mannanase from Bifidobacterium animalis subsp. lactis Bl-04 possesses a low-affinity mannan-binding module and highlights the diversity of mannanolytic enzymes. BMC BIOCHEMISTRY 2015; 16:26. [PMID: 26558435 PMCID: PMC4642672 DOI: 10.1186/s12858-015-0055-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/29/2015] [Indexed: 12/18/2022]
Abstract
Background β-Mannans are abundant and diverse plant structural and storage polysaccharides. Certain human gut microbiota members including health-promoting Bifidobacterium spp. catabolize dietary mannans. Little insight is available on the enzymology of mannan deconstruction in the gut ecological niche. Here, we report the biochemical properties of the first family 5 subfamily 8 glycoside hydrolase (GH5_8) mannanase from the probiotic bacterium Bifidobacterium animalis subsp. lactis Bl-04 (BlMan5_8). Results BlMan5_8 possesses a novel low affinity carbohydrate binding module (CBM) specific for soluble mannan and displays the highest catalytic efficiency reported to date for a GH5 mannanase owing to a very high kcat (1828 ± 87 s-1) and a low Km (1.58 ± 0.23 g · L-1) using locust bean galactomannan as substrate. The novel CBM of BlMan5_8 mediates increased binding to soluble mannan based on affinity electrophoresis. Surface plasmon resonance analysis confirmed the binding of the CBM10 to manno-oligosaccharides, albeit with slightly lower affinity than the catalytic module of the enzyme. This is the first example of a low-affinity mannan-specific CBM, which forms a subfamily of CBM10 together with close homologs present only in mannanases. Members of this new subfamily lack an aromatic residue mediating binding to insoluble cellulose in canonical CBM10 members consistent with the observed low mannan affinity. Conclusion BlMan5_8 is evolved for efficient deconstruction of soluble mannans, which is reflected by an exceptionally low Km and the presence of an atypical low affinity CBM, which increases binding to specifically to soluble mannan while causing minimal decrease in catalytic efficiency as opposed to enzymes with canonical mannan binding modules. These features highlight fine tuning of catalytic and binding properties to support specialization towards a preferred substrate, which is likely to confer an advantage in the adaptation to competitive ecological niches. Electronic supplementary material The online version of this article (doi:10.1186/s12858-015-0055-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Johan Morrill
- Department of Biochemistry and Structural Biology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00, Lund, Sweden
| | - Evelina Kulcinskaja
- Department of Biochemistry and Structural Biology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00, Lund, Sweden
| | - Anna Maria Sulewska
- Enzyme and Protein Chemistry (EPC), Department of Systems Biology, Technical University of Denmark (DTU), Søltofts Plads, building 224, DK-2800, Kgs Lyngby, Denmark.,Current address: Biochemistry and Bioprocessing, Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958, Fredriksberg C, Denmark
| | - Sampo Lahtinen
- Active Nutrition, DuPont Nutrition & Health, Sokeritehtaantie 20, 02460, Kantvik, Finland
| | - Henrik Stålbrand
- Department of Biochemistry and Structural Biology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00, Lund, Sweden
| | - Birte Svensson
- Enzyme and Protein Chemistry (EPC), Department of Systems Biology, Technical University of Denmark (DTU), Søltofts Plads, building 224, DK-2800, Kgs Lyngby, Denmark
| | - Maher Abou Hachem
- Enzyme and Protein Chemistry (EPC), Department of Systems Biology, Technical University of Denmark (DTU), Søltofts Plads, building 224, DK-2800, Kgs Lyngby, Denmark.
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52
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Kurašin M, Kuusk S, Kuusk P, Sørlie M, Väljamäe P. Slow Off-rates and Strong Product Binding Are Required for Processivity and Efficient Degradation of Recalcitrant Chitin by Family 18 Chitinases. J Biol Chem 2015; 290:29074-85. [PMID: 26468285 DOI: 10.1074/jbc.m115.684977] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Indexed: 12/18/2022] Open
Abstract
Processive glycoside hydrolases are the key components of enzymatic machineries that decompose recalcitrant polysaccharides, such as chitin and cellulose. The intrinsic processivity (P(Intr)) of cellulases has been shown to be governed by the rate constant of dissociation from polymer chain (koff). However, the reported koff values of cellulases are strongly dependent on the method used for their measurement. Here, we developed a new method for determining koff, based on measuring the exchange rate of the enzyme between a non-labeled and a (14)C-labeled polymeric substrate. The method was applied to the study of the processive chitinase ChiA from Serratia marcescens. In parallel, ChiA variants with weaker binding of the N-acetylglucosamine unit either in substrate-binding site -3 (ChiA-W167A) or the product-binding site +1 (ChiA-W275A) were studied. Both ChiA variants showed increased off-rates and lower apparent processivity on α-chitin. The rate of the production of insoluble reducing groups on the reduced α-chitin was an order of magnitude higher than koff, suggesting that the enzyme can initiate several processive runs without leaving the substrate. On crystalline chitin, the general activity of the wild type enzyme was higher, and the difference was magnifying with hydrolysis time. On amorphous chitin, the variants clearly outperformed the wild type. A model is proposed whereby strong interactions with polymer in the substrate-binding sites (low off-rates) and strong binding of the product in the product-binding sites (high pushing potential) are required for the removal of obstacles, like disintegration of chitin microfibrils.
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Affiliation(s)
| | - Silja Kuusk
- From the Institutes of Molecular and Cell Biology and
| | - Piret Kuusk
- Physics, University of Tartu, 51010 Tartu, Estonia and
| | - Morten Sørlie
- the Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås 1432, Norway
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53
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Borisova AS, Eneyskaya EV, Bobrov KS, Jana S, Logachev A, Polev DE, Lapidus AL, Ibatullin FM, Saleem U, Sandgren M, Payne CM, Kulminskaya AA, Ståhlberg J. Sequencing, biochemical characterization, crystal structure and molecular dynamics of cellobiohydrolase Cel7A from
Geotrichum candidum
3C. FEBS J 2015; 282:4515-37. [DOI: 10.1111/febs.13509] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/13/2015] [Accepted: 09/04/2015] [Indexed: 01/01/2023]
Affiliation(s)
- Anna S. Borisova
- Department of Chemistry and Biotechnology Swedish University of Agricultural Sciences Uppsala Sweden
- National Research Centre «Kurchatov Institute» B.P. Konstantinov Petersburg Nuclear Physics Institute Gatchina Orlova roscha Russia
| | - Elena V. Eneyskaya
- National Research Centre «Kurchatov Institute» B.P. Konstantinov Petersburg Nuclear Physics Institute Gatchina Orlova roscha Russia
| | - Kirill S. Bobrov
- National Research Centre «Kurchatov Institute» B.P. Konstantinov Petersburg Nuclear Physics Institute Gatchina Orlova roscha Russia
| | - Suvamay Jana
- Department of Chemical and Materials Engineering University of Kentucky Lexington KY USA
| | - Anton Logachev
- Theodosius Dobzhansky Center for Genome Bioinformatics St. Petersburg State University Russia
| | - Dmitrii E. Polev
- Research Resource Centre «Molecular and Cell Technologies» St. Petersburg State University Russia
| | - Alla L. Lapidus
- Centre for Algorithmic Biotechnology St. Petersburg Academic University Russia
| | - Farid M. Ibatullin
- National Research Centre «Kurchatov Institute» B.P. Konstantinov Petersburg Nuclear Physics Institute Gatchina Orlova roscha Russia
| | - Umair Saleem
- Department of Chemistry and Biotechnology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Mats Sandgren
- Department of Chemistry and Biotechnology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Christina M. Payne
- Department of Chemical and Materials Engineering University of Kentucky Lexington KY USA
| | - Anna A. Kulminskaya
- National Research Centre «Kurchatov Institute» B.P. Konstantinov Petersburg Nuclear Physics Institute Gatchina Orlova roscha Russia
- Department of Medical Physics Peter the Great St. Petersburg Polytechnic University Russia
| | - Jerry Ståhlberg
- Department of Chemistry and Biotechnology Swedish University of Agricultural Sciences Uppsala Sweden
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54
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Chung PW, Yabushita M, To AT, Bae Y, Jankolovits J, Kobayashi H, Fukuoka A, Katz A. Long-Chain Glucan Adsorption and Depolymerization in Zeolite-Templated Carbon Catalysts. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01172] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Po-Wen Chung
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Mizuho Yabushita
- Catalysis
Research Center, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan
| | - Anh The To
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - YounJue Bae
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Joseph Jankolovits
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Hirokazu Kobayashi
- Catalysis
Research Center, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan
| | - Atsushi Fukuoka
- Catalysis
Research Center, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan
| | - Alexander Katz
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
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55
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Atreya ME, Strobel KL, Clark DS. Alleviating product inhibition in cellulase enzyme Cel7A. Biotechnol Bioeng 2015; 113:330-8. [PMID: 26302366 PMCID: PMC5049672 DOI: 10.1002/bit.25809] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/19/2015] [Accepted: 08/21/2015] [Indexed: 12/19/2022]
Abstract
Enzymes that degrade cellulose into glucose are one of the most expensive components of processes for converting cellulosic biomass to fuels and chemicals. Cellulase enzyme Cel7A is the most abundant enzyme naturally employed by fungi to depolymerize cellulose, and like other cellulases is inhibited by its product, cellobiose. There is thus great economic incentive for minimizing the detrimental effects of product inhibition on Cel7A. In this work, we experimentally generated 10 previously proposed site-directed mutant Cel7A enzymes expected to have reduced cellobiose binding energies (the majority of mutations were to alanine). We then tested their resilience to cellobiose as well as their hydrolytic activities on microcrystalline cellulose. Although every mutation tested conferred reduced product inhibition (and abolished it for some), our results confirm a trade-off between Cel7A tolerance to cellobiose and enzymatic activity: Reduced product inhibition was accompanied by lower overall enzymatic activity on crystalline cellulose for the mutants tested. The tempering effect of mutations on inhibition was nearly constant despite relatively large differences in activities of the mutants. Our work identifies an amino acid in the Cel7A product binding site of interest for further mutational studies, and highlights both the challenge and the opportunity of enzyme engineering toward improving product tolerance in Cel7A.
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Affiliation(s)
- Meera E Atreya
- Department of Chemistry, Chemical Biology Graduate Program, University of California, Berkeley, 94720, California.,Energy Biosciences Institute, University of California, Berkeley, 94720, California
| | - Kathryn L Strobel
- Energy Biosciences Institute, University of California, Berkeley, 94720, California.,Department of Chemical and Biomolecular Engineering, University of California, Berkeley, 94720, California
| | - Douglas S Clark
- Energy Biosciences Institute, University of California, Berkeley, 94720, California. .,Department of Chemical and Biomolecular Engineering, University of California, Berkeley, 94720, California.
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56
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Hamre AG, Jana S, Holen MM, Mathiesen G, Väljamäe P, Payne CM, Sørlie M. Thermodynamic Relationships with Processivity in Serratia marcescens Family 18 Chitinases. J Phys Chem B 2015; 119:9601-13. [PMID: 26154587 DOI: 10.1021/acs.jpcb.5b03817] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The enzymatic degradation of recalcitrant polysaccharides is accomplished by synergistic enzyme cocktails of glycoside hydrolases (GHs) and accessory enzymes. Many GHs are processive which means that they remain attached to the substrate in between subsequent hydrolytic reactions. Chitinases are GHs that catalyze the hydrolysis of chitin (β-1,4-linked N-acetylglucosamine). Previously, a relationship between active site topology and processivity has been suggested while recent computational efforts have suggested a link between the degree of processivity and ligand binding free energy. We have investigated these relationships by employing computational (molecular dynamics (MD)) and experimental (isothermal titration calorimetry (ITC)) approaches to gain insight into the thermodynamics of substrate binding to Serratia marcescens chitinases ChiA, ChiB, and ChiC. We show that increased processive ability indeed corresponds to more favorable binding free energy and that this likely is a general feature of GHs. Moreover, ligand binding in ChiB is entropically driven; in ChiC it is enthalpically driven, and the enthalpic and entropic contributions to ligand binding in ChiA are equal. Furthermore, water is shown to be especially important in ChiA-binding. This work provides new insight into oligosaccharide binding, getting us one step closer to understand how GHs efficiently degrade recalcitrant polysaccharides.
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Affiliation(s)
- Anne Grethe Hamre
- †Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. 5003, N-1432 Ås, Norway
| | - Suvamay Jana
- ‡Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Matilde Mengkrog Holen
- †Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. 5003, N-1432 Ås, Norway
| | - Geir Mathiesen
- †Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. 5003, N-1432 Ås, Norway
| | - Priit Väljamäe
- §Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Christina M Payne
- ‡Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Morten Sørlie
- †Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. 5003, N-1432 Ås, Norway
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57
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Uncovering Molecular Bases Underlying Bone Morphogenetic Protein Receptor Inhibitor Selectivity. PLoS One 2015; 10:e0132221. [PMID: 26133550 PMCID: PMC4489870 DOI: 10.1371/journal.pone.0132221] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/11/2015] [Indexed: 12/22/2022] Open
Abstract
Abnormal alteration of bone morphogenetic protein (BMP) signaling is implicated in many types of diseases including cancer and heterotopic ossifications. Hence, small molecules targeting BMP type I receptors (BMPRI) to interrupt BMP signaling are believed to be an effective approach to treat these diseases. However, lack of understanding of the molecular determinants responsible for the binding selectivity of current BMP inhibitors has been a big hindrance to the development of BMP inhibitors for clinical use. To address this issue, we carried out in silico experiments to test whether computational methods can reproduce and explain the high selectivity of a small molecule BMP inhibitor DMH1 on BMPRI kinase ALK2 vs. the closely related TGF-β type I receptor kinase ALK5 and vascular endothelial growth factor receptor type 2 (VEGFR2) tyrosine kinase. We found that, while the rigid docking method used here gave nearly identical binding affinity scores among the three kinases; free energy perturbation coupled with Hamiltonian replica-exchange molecular dynamics (FEP/H-REMD) simulations reproduced the absolute binding free energies in excellent agreement with experimental data. Furthermore, the binding poses identified by FEP/H-REMD led to a quantitative analysis of physical/chemical determinants governing DMH1 selectivity. The current work illustrates that small changes in the binding site residue type (e.g. pre-hinge region in ALK2 vs. ALK5) or side chain orientation (e.g. Tyr219 in caALK2 vs. wtALK2), as well as a subtle structural modification on the ligand (e.g. DMH1 vs. LDN193189) will cause distinct binding profiles and selectivity among BMP inhibitors. Therefore, the current computational approach represents a new way of investigating BMP inhibitors. Our results provide critical information for designing exclusively selective BMP inhibitors for the development of effective pharmacotherapy for diseases caused by aberrant BMP signaling.
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58
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Vermaas JV, Crowley MF, Beckham GT, Payne CM. Effects of lytic polysaccharide monooxygenase oxidation on cellulose structure and binding of oxidized cellulose oligomers to cellulases. J Phys Chem B 2015; 119:6129-43. [PMID: 25785779 DOI: 10.1021/acs.jpcb.5b00778] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In nature, polysaccharide glycosidic bonds are cleaved by hydrolytic enzymes for a vast array of biological functions. Recently, a new class of enzymes that utilize an oxidative mechanism to cleave glycosidic linkages was discovered; these enzymes are called lytic polysaccharide monooxygenases (LPMO). These oxidative enzymes are synergistic with cocktails of hydrolytic enzymes and are thought to act primarily on crystalline regions, in turn providing new sites of productive attachment and detachment for processive hydrolytic enzymes. In the case of cellulose, the homopolymer of β-1,4-d-glucose, enzymatic oxidation occurs at either the reducing end or the nonreducing end of glucose, depending on enzymatic specificity, and results in the generation of oxidized chemical substituents at polymer chain ends. LPMO oxidation of cellulose is thought to produce either a lactone at the reducing end of glucose that can spontaneously or enzymatically convert to aldonic acid or 4-keto-aldose at the nonreducing end that may further oxidize to a geminal diol. Here, we use molecular simulation to examine the effect of oxidation on the structure of crystalline cellulose. The simulations highlight variations in behaviors depending on the chemical identity of the oxidized species and its location within the cellulose fibril, as different oxidized species introduce steric effects that disrupt local crystallinity and in some cases reduce the work needed for polymer decrystallization. Reducing-end oxidations are easiest to decrystallize when located at the end of the fibril, whereas nonreducing end oxidations readily decrystallize from internal cleavage sites despite their lower solvent accessibility. The differential in decrystallization free energy suggests a molecular mechanism consistent with experimentally observed LPMO/cellobiohydrolase synergy. Additionally, the soluble oxidized cellobiose products released by hydrolytic cellulases may bind to the active sites of cellulases with different affinities relative to cellobiose itself, which potentially affects hydrolytic turnover through product inhibition. To examine the effect of oxidation on cello-oligomer binding, we use thermodynamic integration to compute the relative change in binding free energy between the hydrolyzed and oxidized products in the active site of Family 7 and Family 6 processive glycoside hydrolases, Trichoderma reesei Cel7A and Cel6A, which are key industrial cellulases and commonly used model systems for fungal cellulases. Our results suggest that the equilibrium between the two reducing end oxidized products, favoring the linear aldonic acid, may increase product inhibition, which would in turn reduce processive substrate turnover. In the case of LMPO action at the nonreducing end, oxidation appears to lower affinity with the nonreducing end specific cellulase, reducing product inhibition and potentially promoting processive cellulose turnover. Overall, this suggests that oxidation of recalcitrant polysaccharides by LPMOs accelerates degradation not only by increasing the concentration of chain termini but also by reducing decrystallization work, and that product inhibition may be somewhat reduced as a result.
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Affiliation(s)
- Josh V Vermaas
- †Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,‡National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Michael F Crowley
- §Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Gregg T Beckham
- ‡National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Christina M Payne
- ∥Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506, United States.,⊥Center for Computational Science, University of Kentucky, Lexington, Kentucky 40506, United States
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59
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Kuusk S, Sørlie M, Väljamäe P. The predominant molecular state of bound enzyme determines the strength and type of product inhibition in the hydrolysis of recalcitrant polysaccharides by processive enzymes. J Biol Chem 2015; 290:11678-91. [PMID: 25767120 DOI: 10.1074/jbc.m114.635631] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Indexed: 11/06/2022] Open
Abstract
Processive enzymes are major components of the efficient enzyme systems that are responsible for the degradation of the recalcitrant polysaccharides cellulose and chitin. Despite intensive research, there is no consensus on which step is rate-limiting for these enzymes. Here, we performed a comparative study of two well characterized enzymes, the cellobiohydrolase Cel7A from Hypocrea jecorina and the chitinase ChiA from Serratia marcescens. Both enzymes were inhibited by their disaccharide product, namely chitobiose for ChiA and cellobiose for Cel7A. The products behaved as noncompetitive inhibitors according to studies using the (14)C-labeled crystalline polymeric substrates (14)C chitin nanowhiskers and (14)C-labeled bacterial microcrystalline cellulose for ChiA and Cel7A, respectively. The resulting observed Ki (obs) values were 0.45 ± 0.08 mm for ChiA and 0.17 ± 0.02 mm for Cel7A. However, in contrast to ChiA, the Ki (obs) of Cel7A was an order of magnitude higher than the true Ki value governed by the thermodynamic stability of the enzyme-inhibitor complex. Theoretical analysis of product inhibition suggested that the inhibition strength and pattern can be accounted for by assuming different rate-limiting steps for ChiA and Cel7A. Measuring the population of enzymes whose active site was occupied by a polymer chain revealed that Cel7A was bound predominantly via its active site. Conversely, the active-site-mediated binding of ChiA was slow, and most ChiA exhibited a free active site, even when the substrate concentration was saturating for the activity. Collectively, our data suggest that complexation with the polymer chain is rate-limiting for ChiA, whereas Cel7A is limited by dissociation.
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Affiliation(s)
- Silja Kuusk
- From the Institute of Molecular and Cell Biology, University of Tartu, 51010 Tartu, Estonia and
| | - Morten Sørlie
- the Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Priit Väljamäe
- From the Institute of Molecular and Cell Biology, University of Tartu, 51010 Tartu, Estonia and
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60
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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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61
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Greene ER, Himmel ME, Beckham GT, Tan Z. Glycosylation of Cellulases: Engineering Better Enzymes for Biofuels. Adv Carbohydr Chem Biochem 2015; 72:63-112. [PMID: 26613815 DOI: 10.1016/bs.accb.2015.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Cellulose in plant cell walls is the largest reservoir of renewable carbon on Earth. The saccharification of cellulose from plant biomass into soluble sugars can be achieved using fungal and bacterial cellulolytic enzymes, cellulases, and further converted into fuels and chemicals. Most fungal cellulases are both N- and O-glycosylated in their native form, yet the consequences of glycosylation on activity and structure are not fully understood. Studying protein glycosylation is challenging as glycans are extremely heterogeneous, stereochemically complex, and glycosylation is not under direct genetic control. Despite these limitations, many studies have begun to unveil the role of cellulase glycosylation, especially in the industrially relevant cellobiohydrolase from Trichoderma reesei, Cel7A. Glycosylation confers many beneficial properties to cellulases including enhanced activity, thermal and proteolytic stability, and structural stabilization. However, glycosylation must be controlled carefully as such positive effects can be dampened or reversed. Encouragingly, methods for the manipulation of glycan structures have been recently reported that employ genetic tuning of glycan-active enzymes expressed from homogeneous and heterologous fungal hosts. Taken together, these studies have enabled new strategies for the exploitation of protein glycosylation for the production of enhanced cellulases for biofuel production.
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62
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Siriwardena A, Khanal M, Barras A, Bande O, Mena-Barragán T, Mellet CO, Garcia Fernández JM, Boukherroub R, Szunerits S. Unprecedented inhibition of glycosidase-catalyzed substrate hydrolysis by nanodiamond-grafted O-glycosides. RSC Adv 2015. [DOI: 10.1039/c5ra21390h] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Carbohydrate-coated nanodiamond particles with lectin recognition capabilities are not only stable towards the hydrolytic action of glycosidases, but also are endowed with the ability to inhibit them.
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Affiliation(s)
- Aloysius Siriwardena
- Laboratoire de Glycochimie des Antimicrobiennes et Bioresources
- FRE-CNRS 3517
- Université de Picardie Jules Verne
- 80039 Amiens
- France
| | - Manakamana Khanal
- Institute of Electronics
- Microelectronics and Nanotechnology (IEMN)
- UMR-CNRS 8520
- Lille1 University
- Avenue Poincaré-BP 60069
| | - Alexandre Barras
- Institute of Electronics
- Microelectronics and Nanotechnology (IEMN)
- UMR-CNRS 8520
- Lille1 University
- Avenue Poincaré-BP 60069
| | - Omprakash Bande
- Laboratoire de Glycochimie des Antimicrobiennes et Bioresources
- FRE-CNRS 3517
- Université de Picardie Jules Verne
- 80039 Amiens
- France
| | | | | | | | - Rabah Boukherroub
- Institute of Electronics
- Microelectronics and Nanotechnology (IEMN)
- UMR-CNRS 8520
- Lille1 University
- Avenue Poincaré-BP 60069
| | - Sabine Szunerits
- Institute of Electronics
- Microelectronics and Nanotechnology (IEMN)
- UMR-CNRS 8520
- Lille1 University
- Avenue Poincaré-BP 60069
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63
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Silveira RL, Skaf MS. Molecular Dynamics Simulations of Family 7 Cellobiohydrolase Mutants Aimed at Reducing Product Inhibition. J Phys Chem B 2014; 119:9295-303. [DOI: 10.1021/jp509911m] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Rodrigo L. Silveira
- Institute
of Chemistry, University of Campinas, Cx. P. 6154 Campinas, SP, 13084-862, Brazil
| | - Munir S. Skaf
- Institute
of Chemistry, University of Campinas, Cx. P. 6154 Campinas, SP, 13084-862, Brazil
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Colussi F, Sørensen TH, Alasepp K, Kari J, Cruys-Bagger N, Windahl MS, Olsen JP, Borch K, Westh P. Probing substrate interactions in the active tunnel of a catalytically deficient cellobiohydrolase (Cel7). J Biol Chem 2014; 290:2444-54. [PMID: 25477511 DOI: 10.1074/jbc.m114.624163] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellobiohydrolases break down cellulose sequentially by sliding along the crystal surface with a single cellulose strand threaded through the catalytic tunnel of the enzyme. This so-called processive mechanism relies on a complex pattern of enzyme-substrate interactions, which need to be addressed in molecular descriptions of processivity and its driving forces. Here, we have used titration calorimetry to study interactions of cellooligosaccharides (COS) and a catalytically deficient variant (E212Q) of the enzyme Cel7A from Trichoderma reesei. This enzyme has ∼10 glucopyranose subsites in the catalytic tunnel, and using COS ligands with a degree of polymerization (DP) from 2 to 8, different regions of the tunnel could be probed. For COS ligands with a DP of 2-3 the binding constants were around 10(5) m(-1), and for longer ligands (DP 5-8) this value was ∼10(7) m(-1). Within each of these groups we did not find increased affinity as the ligands got longer and potentially filled more subsites. On the contrary, we found a small but consistent affinity loss as DP rose from 6 to 8, particularly at the higher investigated temperatures. Other thermodynamic functions (ΔH, ΔS, and ΔCp) decreased monotonously with both temperature and DP. Combined interpretation of these thermodynamic results and previously published structural data allowed assessment of an affinity profile along the length axis of the active tunnel.
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Affiliation(s)
- Francieli Colussi
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and
| | - Trine H Sørensen
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and
| | - Kadri Alasepp
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and
| | - Jeppe Kari
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and
| | - Nicolaj Cruys-Bagger
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and
| | - Michael S Windahl
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and Novozymes A/S, Krogshøjvej 36, DK-2880, Bagsværd, Denmark
| | - Johan P Olsen
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and
| | - Kim Borch
- Novozymes A/S, Krogshøjvej 36, DK-2880, Bagsværd, Denmark
| | - Peter Westh
- From the Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Denmark and
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65
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Enzyme processivity changes with the extent of recalcitrant polysaccharide degradation. FEBS Lett 2014; 588:4620-4. [DOI: 10.1016/j.febslet.2014.10.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/16/2014] [Accepted: 10/16/2014] [Indexed: 11/23/2022]
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66
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Kari J, Olsen J, Borch K, Cruys-Bagger N, Jensen K, Westh P. Kinetics of cellobiohydrolase (Cel7A) variants with lowered substrate affinity. J Biol Chem 2014; 289:32459-68. [PMID: 25271162 DOI: 10.1074/jbc.m114.604264] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellobiohydrolases are exo-active glycosyl hydrolases that processively convert cellulose to soluble sugars, typically cellobiose. They effectively break down crystalline cellulose and make up a major component in industrial enzyme mixtures used for deconstruction of lignocellulosic biomass. Identification of the rate-limiting step for cellobiohydrolases remains controversial, and recent reports have alternately suggested either association (on-rate) or dissociation (off-rate) as the overall bottleneck. Obviously, this uncertainty hampers both fundamental mechanistic understanding and rational design of enzymes with improved industrial applicability. To elucidate the role of on- and off-rates, respectively, on the overall kinetics, we have expressed a variant in which a tryptophan residue (Trp-38) in the middle of the active tunnel has been replaced with an alanine. This mutation weakens complex formation, and the population of substrate-bound W38A was only about half of the wild type. Nevertheless, the maximal, steady-state rate was twice as high for the variant enzyme. It is argued that these opposite effects on binding and activity can be reconciled if the rate-limiting step is after the catalysis (i.e. in the dissociation process).
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Affiliation(s)
- Jeppe Kari
- From Department of Science, Systems and Models, Research Unit for Functional Biomaterials, Roskilde University, 1 Universitetsvej, DK-4000 Roskilde, Denmark and
| | - Johan Olsen
- From Department of Science, Systems and Models, Research Unit for Functional Biomaterials, Roskilde University, 1 Universitetsvej, DK-4000 Roskilde, Denmark and
| | - Kim Borch
- Novozymes A/S, Krogshøjvej 36, Bagsværd DK-2880, Denmark
| | - Nicolaj Cruys-Bagger
- From Department of Science, Systems and Models, Research Unit for Functional Biomaterials, Roskilde University, 1 Universitetsvej, DK-4000 Roskilde, Denmark and
| | - Kenneth Jensen
- Novozymes A/S, Krogshøjvej 36, Bagsværd DK-2880, Denmark
| | - Peter Westh
- From Department of Science, Systems and Models, Research Unit for Functional Biomaterials, Roskilde University, 1 Universitetsvej, DK-4000 Roskilde, Denmark and
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67
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68
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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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69
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Igarashi K, Uchihashi T, Uchiyama T, Sugimoto H, Wada M, Suzuki K, Sakuda S, Ando T, Watanabe T, Samejima M. Two-way traffic of glycoside hydrolase family 18 processive chitinases on crystalline chitin. Nat Commun 2014; 5:3975. [DOI: 10.1038/ncomms4975] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 04/25/2014] [Indexed: 11/09/2022] Open
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70
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Towards a molecular-level theory of carbohydrate processivity in glycoside hydrolases. Curr Opin Biotechnol 2014; 27:96-106. [DOI: 10.1016/j.copbio.2013.12.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 12/04/2013] [Indexed: 10/25/2022]
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71
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Granum DM, Schutt TC, Maupin CM. Computational Evaluation of the Dynamic Fluctuations of Peripheral Loops Enclosing the Catalytic Tunnel of a Family 7 Cellobiohydrolase. J Phys Chem B 2014; 118:5340-9. [DOI: 10.1021/jp5011555] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David M. Granum
- Chemical
and Biological Engineering
Department, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States
| | - Timothy C. Schutt
- Chemical
and Biological Engineering
Department, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States
| | - C. Mark Maupin
- Chemical
and Biological Engineering
Department, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States
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72
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Shibafuji Y, Nakamura A, Uchihashi T, Sugimoto N, Fukuda S, Watanabe H, Samejima M, Ando T, Noji H, Koivula A, Igarashi K, Iino R. Single-molecule imaging analysis of elementary reaction steps of Trichoderma reesei cellobiohydrolase I (Cel7A) hydrolyzing crystalline cellulose Iα and IIII. J Biol Chem 2014; 289:14056-65. [PMID: 24692563 DOI: 10.1074/jbc.m113.546085] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trichoderma reesei cellobiohydrolase I (TrCel7A) is a molecular motor that directly hydrolyzes crystalline celluloses into water-soluble cellobioses. It has recently drawn attention as a tool that could be used to convert cellulosic materials into biofuel. However, detailed mechanisms of action, including elementary reaction steps such as binding, processive hydrolysis, and dissociation, have not been thoroughly explored because of the inherent challenges associated with monitoring reactions occurring at the solid/liquid interface. The crystalline cellulose Iα and IIII were previously reported as substrates with different crystalline forms and different susceptibilities to hydrolysis by TrCel7A. In this study, we observed that different susceptibilities of cellulose Iα and IIII are highly dependent on enzyme concentration, and at nanomolar enzyme concentration, TrCel7A shows similar rates of hydrolysis against cellulose Iα and IIII. Using single-molecule fluorescence microscopy and high speed atomic force microscopy, we also determined kinetic constants of the elementary reaction steps for TrCel7A against cellulose Iα and IIII. These measurements were performed at picomolar enzyme concentration in which density of TrCel7A on crystalline cellulose was very low. Under this condition, TrCel7A displayed similar binding and dissociation rate constants for cellulose Iα and IIII and similar fractions of productive binding on cellulose Iα and IIII. Furthermore, once productively bound, TrCel7A processively hydrolyzes and moves along cellulose Iα and IIII with similar translational rates. With structural models of cellulose Iα and IIII, we propose that different susceptibilities at high TrCel7A concentration arise from surface properties of substrate, including ratio of hydrophobic surface and number of available lanes.
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Affiliation(s)
- Yusuke Shibafuji
- From the Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Akihiko Nakamura
- the Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Takayuki Uchihashi
- the Department of Physics, College of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan, the Bio-AFM Frontier Research Center, College of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan, and
| | - Naohisa Sugimoto
- the Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Shingo Fukuda
- the Department of Physics, College of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan
| | - Hiroki Watanabe
- the Department of Physics, College of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan
| | - Masahiro Samejima
- the Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Toshio Ando
- the Department of Physics, College of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan, the Bio-AFM Frontier Research Center, College of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan, and
| | - Hiroyuki Noji
- From the Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Anu Koivula
- the VTT Technical Research Centre of Finland, Espoo, FI-02044 VTT, Finland
| | - Kiyohiko Igarashi
- the Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Ryota Iino
- From the Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan,
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73
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Nakamura A, Watanabe H, Ishida T, Uchihashi T, Wada M, Ando T, Igarashi K, Samejima M. Trade-off between processivity and hydrolytic velocity of cellobiohydrolases at the surface of crystalline cellulose. J Am Chem Soc 2014; 136:4584-92. [PMID: 24571226 DOI: 10.1021/ja4119994] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Analysis of heterogeneous catalysis at an interface is difficult because of the variety of reaction sites and the difficulty of observing the reaction. Enzymatic hydrolysis of cellulose by cellulases is a typical heterogeneous reaction at a solid/liquid interface, and a key parameter of such reactions on polymeric substrates is the processivity, i.e., the number of catalytic cycles that can occur without detachment of the enzyme from the substrate. In this study, we evaluated the reactions of three closely related glycoside hydrolase family 7 cellobiohydrolases from filamentous fungi at the molecular level by means of high-speed atomic force microscopy to investigate the structure-function relationship of the cellobiohydrolases on crystalline cellulose. We found that high moving velocity of enzyme molecules on the surface is associated with a high dissociation rate constant from the substrate, which means weak interaction between enzyme and substrate. Moreover, higher values of processivity were associated with more loop regions covering the subsite cleft, which may imply higher binding affinity. Loop regions covering the subsites result in stronger interaction, which decreases the velocity but increases the processivity. These results indicate that there is a trade-off between processivity and hydrolytic velocity among processive cellulases.
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Affiliation(s)
- Akihiko Nakamura
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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