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Farren-Dai M, Sannikova N, Świderek K, Moliner V, Bennet AJ. Fundamental Insight into Glycoside Hydrolase-Catalyzed Hydrolysis of the Universal Koshland Substrates–Glycopyranosyl Fluorides. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marco Farren-Dai
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Natalia Sannikova
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Katarzyna Świderek
- Biocomp Group, Institute of Advanced Materials (INAM), Universitat Jaume I, Castellón 12071, Spain
| | - Vicent Moliner
- Biocomp Group, Institute of Advanced Materials (INAM), Universitat Jaume I, Castellón 12071, Spain
| | - Andrew J. Bennet
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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2
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Wallace MD, Stubbs KA. General Synthesis of 3,4‐Dinitrophenyl α‐Glycopyranosides. ChemistrySelect 2019. [DOI: 10.1002/slct.201903489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Michael D. Wallace
- School of Molecular SciencesUniversity of Western Australia 35 Stirling Highway Crawley WA 6009 Australia
| | - Keith A. Stubbs
- School of Molecular SciencesUniversity of Western Australia 35 Stirling Highway Crawley WA 6009 Australia
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3
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Durand J, Biarnés X, Watterlot L, Bonzom C, Borsenberger V, Planas A, Bozonnet S, O’Donohue MJ, Fauré R. A Single Point Mutation Alters the Transglycosylation/Hydrolysis Partition, Significantly Enhancing the Synthetic Capability of an endo-Glycoceramidase. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02159] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Julien Durand
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Xevi Biarnés
- Laboratory
of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Laurie Watterlot
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Cyrielle Bonzom
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | | | - Antoni Planas
- Laboratory
of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Sophie Bozonnet
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | | | - Régis Fauré
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
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4
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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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5
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Volkov PV, Rozhkova AM, Gusakov AV, Sinitsyn AP. Homologous cloning, purification and characterization of highly active cellobiohydrolase I (Cel7A) from Penicillium canescens. Protein Expr Purif 2014; 103:1-7. [PMID: 25162433 DOI: 10.1016/j.pep.2014.08.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 08/13/2014] [Accepted: 08/14/2014] [Indexed: 01/13/2023]
Abstract
Penicillium canescens is a filamentous fungus that normally does not secrete notable levels of cellulase activity. Cellobiohydrolase I of P. canescens (PcCel7A) was homologously cloned into a host strain RN3-11-7 (niaD-) and then expressed under the control of a strong xylA promoter. Using three steps of chromatography, PcCel7A was purified. The enzyme displayed maximum activity at pH 4.0-4.5. PcCel7A was stable at 50°C and pH 4.5 at least for 3h, while at 60°C it lost 45% of activity after 30min of incubation. When equalized by protein concentration, PcCel7A demonstrated a higher performance in prolonged hydrolysis of Avicel and milled aspen wood than CBH I (Cel7A) from Trichoderma reesei, the most industrially utilized cellulase at this moment. The high catalytic efficiency of the PcCel7A makes it a potential candidate for industrial applications.
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Affiliation(s)
- Pavel V Volkov
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky Pr. 33, Moscow 119071, Russia
| | - Alexandra M Rozhkova
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky Pr. 33, Moscow 119071, Russia
| | - Alexander V Gusakov
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky Pr. 33, Moscow 119071, Russia; Department of Chemistry, M. V. Lomonosov Moscow State University, Vorobyovy Gory 1/11, Moscow 119991, Russia.
| | - Arkady P Sinitsyn
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky Pr. 33, Moscow 119071, Russia; Department of Chemistry, M. V. Lomonosov Moscow State University, Vorobyovy Gory 1/11, Moscow 119991, Russia
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6
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7
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Jordan DB, Wagschal K. Properties and applications of microbial β-D-xylosidases featuring the catalytically efficient enzyme from Selenomonas ruminantium. Appl Microbiol Biotechnol 2010; 86:1647-58. [DOI: 10.1007/s00253-010-2538-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 03/02/2010] [Accepted: 03/03/2010] [Indexed: 11/28/2022]
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8
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Hidaka M, Fushinobu S, Honda Y, Wakagi T, Shoun H, Kitaoka M. Structural explanation for the acquisition of glycosynthase activity. ACTA ACUST UNITED AC 2010; 147:237-44. [PMID: 19819900 DOI: 10.1093/jb/mvp159] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Masafumi Hidaka
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
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9
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Gloster TM, Davies GJ. Glycosidase inhibition: assessing mimicry of the transition state. Org Biomol Chem 2010; 8:305-20. [PMID: 20066263 PMCID: PMC2822703 DOI: 10.1039/b915870g] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 09/30/2009] [Indexed: 12/15/2022]
Abstract
Glycoside hydrolases, the enzymes responsible for hydrolysis of the glycosidic bond in di-, oligo- and polysaccharides, and glycoconjugates, are ubiquitous in Nature and fundamental to existence. The extreme stability of the glycosidic bond has meant these enzymes have evolved into highly proficient catalysts, with an estimated 10(17) fold rate enhancement over the uncatalysed reaction. Such rate enhancements mean that enzymes bind the substrate at the transition state with extraordinary affinity; the dissociation constant for the transition state is predicted to be 10(-22) M. Inhibition of glycoside hydrolases has widespread application in the treatment of viral infections, such as influenza and HIV, lysosomal storage disorders, cancer and diabetes. If inhibitors are designed to mimic the transition state, it should be possible to harness some of the transition state affinity, resulting in highly potent and specific drugs. Here we examine a number of glycosidase inhibitors which have been developed over the past half century, either by Nature or synthetically by man. A number of criteria have been proposed to ascertain which of these inhibitors are true transition state mimics, but these features have only be critically investigated in a very few cases.
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Affiliation(s)
- Tracey M. Gloster
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, UK. ; ; Fax: +44 1904 328266; Tel: +44 1904 328260
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Gideon J. Davies
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, UK. ; ; Fax: +44 1904 328266; Tel: +44 1904 328260
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10
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Kitaoka M, Honda Y, Fushinobu S, Hidaka M, Katayama T, Yamamoto K. Conversion of inverting glycoside hydrolases into catalysts for synthesizing glycosides employing a glycosynthase strategy. TRENDS GLYCOSCI GLYC 2009. [DOI: 10.4052/tigg.21.23] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Honda Y, Fushinobu S, Hidaka M, Wakagi T, Shoun H, Taniguchi H, Kitaoka M. Conversion of an Inverting Glycoside Hydrolase into Glycosynthase. J Appl Glycosci (1999) 2009. [DOI: 10.5458/jag.56.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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12
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Percival Zhang YH, Himmel ME, Mielenz JR. Outlook for cellulase improvement: screening and selection strategies. Biotechnol Adv 2006; 24:452-81. [PMID: 16690241 DOI: 10.1016/j.biotechadv.2006.03.003] [Citation(s) in RCA: 662] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 03/06/2006] [Accepted: 03/11/2006] [Indexed: 10/24/2022]
Abstract
Cellulose is the most abundant renewable natural biological resource, and the production of biobased products and bioenergy from less costly renewable lignocellulosic materials is important for the sustainable development of human beings. A reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitution of cellulase components. Here, we review quantitative cellulase activity assays using soluble and insoluble substrates, and focus on their advantages and limitations. Because there are no clear relationships between cellulase activities on soluble substrates and those on insoluble substrates, soluble substrates should not be used to screen or select improved cellulases for processing relevant solid substrates, such as plant cell walls. Cellulase improvement strategies based on directed evolution using screening on soluble substrates have been only moderately successful, and have primarily targeted improvement in thermal tolerance. Heterogeneity of insoluble cellulose, unclear dynamic interactions between insoluble substrate and cellulase components, and the complex competitive and/or synergic relationship among cellulase components limit rational design and/or strategies, depending on activity screening approaches. Herein, we hypothesize that continuous culture using insoluble cellulosic substrates could be a powerful selection tool for enriching beneficial cellulase mutants from the large library displayed on the cell surface.
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Affiliation(s)
- Y-H Percival Zhang
- Biological Systems Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
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13
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Honda Y, Kitaoka M. The first glycosynthase derived from an inverting glycoside hydrolase. J Biol Chem 2005; 281:1426-31. [PMID: 16301312 DOI: 10.1074/jbc.m511202200] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Reducing end xylose-releasing exooligoxylanase (Rex, EC 3.2.1.156) is an inverting GH that hydrolyzes xylooligosaccharides (> or = X3) to release X1 at their reducing end. The wild-type enzyme exhibited the Hehre resynthesis hydrolysis mechanism, in which alpha-X2F was hydrolyzed to X2 and HF in the presence of X1 as an acceptor molecule. However, the transglycosidation product (X3) was not detectable in the reaction. To convert reducing end xylose-releasing exooligoxylanase to glycosynthase, derivatives with mutations in the catalytic base (Asp-263) were constructed by saturation random mutagenesis. Nine amino acid residue mutants (Asp-263 to Gly, Ala, Val, Thr, Leu, Asn, Cys, Pro, or Ser) were found to possess glycosynthase activity forming X3 from alpha-X2F and X1. Among them, D263C showed the highest level of X3 production, and D263N exhibited the fastest consumption of alpha-X2F. The D263C mutant showed 10-fold lower hydrolytic activity than D263N, resulting in the highest yield of X3. X2 was formed from the early stage of the reaction of the D263C mutant, indicating that a portion of the X3 formed by condensation was hydrolyzed before its release from the enzyme. To acquire glycosynthase activity from inverting enzymes, it is important to minimize the decrease in F(-)-releasing activity while maximizing the decrease in the hydrolytic activity. The present study expands the possibility of conversion of glycosynthases from inverting enzymes.
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Affiliation(s)
- Yuji Honda
- National Food Research Institute, 2-1-12, Kannondai, Tsukuba, Ibaraki 305-8642, Japan
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14
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Purification, cloning and characterisation of two forms of thermostable and highly active cellobiohydrolase I (Cel7A) produced by the industrial strain of Chrysosporium lucknowense. Enzyme Microb Technol 2005. [DOI: 10.1016/j.enzmictec.2004.03.025] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Koivula A, Ruohonen L, Wohlfahrt G, Reinikainen T, Teeri TT, Piens K, Claeyssens M, Weber M, Vasella A, Becker D, Sinnott ML, Zou JY, Kleywegt GJ, Szardenings M, Ståhlberg J, Jones TA. The active site of cellobiohydrolase Cel6A from Trichoderma reesei: the roles of aspartic acids D221 and D175. J Am Chem Soc 2002; 124:10015-24. [PMID: 12188666 DOI: 10.1021/ja012659q] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Trichoderma reesei cellobiohydrolase Cel6A is an inverting glycosidase. Structural studies have established that the tunnel-shaped active site of Cel6A contains two aspartic acids, D221 and D175, that are close to the glycosidic oxygen of the scissile bond and at hydrogen-bonding distance from each other. Here, site-directed mutagenesis, X-ray crystallography, and enzyme kinetic studies have been used to confirm the role of residue D221 as the catalytic acid. D175 is shown to affect protonation of D221 and to contribute to the electrostatic stabilization of the partial positive charge in the transition state. Structural and modeling studies suggest that the single-displacement mechanism of Cel6A may not directly involve a catalytic base. The value of (D2O)(V) of 1.16 +/- 0.14 for hydrolysis of cellotriose suggests that the large direct effect expected for proton transfer from the nucleophilic water through a water chain (Grotthus mechanism) is offset by an inverse effect arising from reversibly breaking the short, tight hydrogen bond between D221 and D175 before catalysis.
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Affiliation(s)
- Anu Koivula
- VTT Biotechnology, P.O. Box 1500, FIN-02044 VTT, Espoo, Finland
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16
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Tuohy MG, Walsh DJ, Murray PG, Claeyssens M, Cuffe MM, Savage AV, Coughlan MP. Kinetic parameters and mode of action of the cellobiohydrolases produced by Talaromyces emersonii. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1596:366-80. [PMID: 12007616 DOI: 10.1016/s0167-4838(01)00308-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Three forms of cellobiohydrolase (EC 3.2.1.91), CBH IA, CBH IB and CBH II, were isolated to apparent homogeneity from culture filtrates of the aerobic fungus Talaromyces emersonii. The three enzymes are single sub-unit glycoproteins, and unlike most other fungal cellobiohydrolases are characterised by noteworthy thermostability. The kinetic properties and mode of action of each enzyme against polymeric and small soluble oligomeric substrates were investigated in detail. CBH IA, CBH IB and CBH II catalyse the hydrolysis of microcrystalline cellulose, albeit to varying extents. Hydrolysis of a soluble cellulose derivative (CMC) and barley 1,3;1,4-beta-D-glucan was not observed. Cellobiose (G2) is the main reaction product released by CBH IA, CBH IB, and CBH II from microcrystalline cellulose. All three CBHs are competitively inhibited by G2; inhibition constant values (K(i)) of 2.5 and 0.18 mM were obtained for CBH IA and CBH IB, respectively (4-nitrophenyl-beta-cellobioside as substrate), while a K(i) of 0.16 mM was determined for CBH II (2-chloro-4-nitrophenyl-beta-cellotrioside as substrate). Bond cleavage patterns were determined for each CBH on 4-methylumbelliferyl derivatives of beta-cellobioside and beta-cellotrioside (MeUmbG(n)). While the Tal. emersonii CBHs share certain properties with their counterparts from Trichoderma reesei, Humicola insolens and other fungal sources, distinct differences were noted.
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Affiliation(s)
- Maria G Tuohy
- Department of Biochemistry, National University of Ireland, Galway, Ireland.
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17
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Abstract
Glycosyl fluorides have considerable importance as substrates and inhibitors in enzymatic reactions. Their good combination of stability and reactivity has enabled their use as glycosyl donors with a variety of carbohydrate processing enzymes. Moreover, the installation of fluorine elsewhere on the carbohydrate scaffold commonly modifies the properties of the glycosyl fluoride such that the resultant compounds act as slow substrates or even inhibitors of enzyme action. This review covers the use of glycosyl fluorides as substrates for wild-type and mutant glycosidases and other enzymes that catalyze glycosyl transfer. The use of substituted glycosyl fluorides as inhibitors of enzymes that catalyze glycosyl transfer and as tools for investigation of their mechanism is discussed, including the labeling of active site residues. Synthetic applications in which glycosyl fluorides are used as glycosyl donors in enzymatic transglycosylation reactions for the synthesis of oligo- and polysaccharides are then covered, including the use of mutant glycosidases, the so-called glycosynthases, which are able to catalyze the formation of glycosides without competing hydrolysis. Finally, a short overview of the use of glycosyl fluorides as substrates and inhibitors of phosphorylases and phosphoglucomutase is given.
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Affiliation(s)
- S J Williams
- Department of Chemistry, University of British Columbia, Vancouver, Canada
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Davies GJ, Brzozowski AM, Dauter M, Varrot A, Schülein M. Structure and function of Humicola insolens family 6 cellulases: structure of the endoglucanase, Cel6B, at 1.6 A resolution. Biochem J 2000; 348 Pt 1:201-7. [PMID: 10794732 PMCID: PMC1221054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Cellulases are traditionally classified as either endoglucanases or cellobiohydrolases on the basis of their respective catalytic activities on crystalline cellulose, which is generally hydrolysed more efficiently only by the cellobiohydrolases. On the basis of the Trichoderma reesei cellobiohydrolase II structure, it was proposed that the active-site tunnel of cellobiohydrolases permitted the processive hydrolysis of cellulose, whereas the corresponding endoglucanases would display open active-site clefts [Rouvinen, Bergfors, Teeri, Knowles and Jones (1990) Science 249, 380-386]. Glycoside hydrolase family 6 contains both cellobiohydrolases and endoglucanases. The structure of the catalytic core of the family 6 endoglucanase Cel6B from Humicola insolens has been solved by molecular replacement with the known T. reesei cellobiohydrolase II as the search model. Strangely, at the sequence level, this enzyme exhibits the highest sequence similarity to family 6 cellobiohydrolases and displays just one of the loop deletions traditionally associated with endoglucanases in this family. However, this enzyme shows no activity on crystalline substrates but a high activity on soluble substrates, which is typical of an endoglucanase. The three-dimensional structure reveals that the deletion of just a single loop of the active site, coupled with the resultant conformational change in a second 'cellobiohydrolase-specific' loop, peels open the active-site tunnel to reveal a substrate-binding groove.
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Affiliation(s)
- G J Davies
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K.
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19
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Hehre EJ. A fresh understanding of the stereochemical behavior of glycosylases: structural distinction of "inverting" (2-MCO-type) versus "retaining" (1-MCO-type) enzymes. Adv Carbohydr Chem Biochem 2000; 55:265-310. [PMID: 10715782 DOI: 10.1016/s0065-2318(00)55007-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- E J Hehre
- Department of Microbiology and Immmunology, Albert Einstein College of Medicine, New York, USA
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20
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Lougheed B, Ly HD, Wakarchuk WW, Withers SG. Glycosyl fluorides can function as substrates for nucleotide phosphosugar-dependent glycosyltransferases. J Biol Chem 1999; 274:37717-22. [PMID: 10608830 DOI: 10.1074/jbc.274.53.37717] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
alpha-Galactosyl fluoride is shown to function as a substrate, in place of uridine-5'-diphosphogalactose, for the alpha-galactosyltransferase from Neisseria meningitidis. The reaction only occurs in the presence of catalytic quantities of uridine 5'-diphosphate. In the presence of galactosyl acceptors, the expected oligosaccharide product is formed in essentially quantitative yields, reaction having been performed on multi-milligram scales. In the absence of a suitable acceptor, the enzyme synthesizes uridine-5'-diphosphogalactose, as demonstrated through a coupled assay in which uridine-5'-diphosphogalactose is converted to uridine-5'-diphosphoglucuronic acid with conversion of NAD to NADH. These glycosyl fluoride substrates therefore offer the potential of an inexpensive alternative donor substrate in the synthesis of oligosaccharides as well a means of generating steady state concentrations of nucleotide diphosphate sugars for in situ use by other enzymes. Further, they should prove valuable as mechanistic probes.
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Affiliation(s)
- B Lougheed
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1
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21
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Zou JY, Kleywegt GJ, Ståhlberg J, Driguez H, Nerinckx W, Claeyssens M, Koivula A, Teeri TT, Jones TA. Crystallographic evidence for substrate ring distortion and protein conformational changes during catalysis in cellobiohydrolase Ce16A from trichoderma reesei. Structure 1999; 7:1035-45. [PMID: 10508787 DOI: 10.1016/s0969-2126(99)80171-3] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cel6A is one of the two cellobiohydrolases produced by Trichoderma reesei. The catalytic core has a structure that is a variation of the classic TIM barrel. The active site is located inside a tunnel, the roof of which is formed mainly by a pair of loops. RESULTS We describe three new ligand complexes. One is the structure of the wild-type enzyme in complex with a nonhydrolysable cello-oligosaccharide, methyl 4-S-beta-cellobiosyl-4-thio-beta-cellobioside (Glc)(2)-S-(Glc)(2), which differs from a cellotetraose in the nature of the central glycosidic linkage where a sulphur atom replaces an oxygen atom. The second structure is a mutant, Y169F, in complex with the same ligand, and the third is the wild-type enzyme in complex with m-iodobenzyl beta-D-glucopyranosyl-beta(1,4)-D-xylopyranoside (IBXG). CONCLUSIONS The (Glc)(2)-S-(Glc)(2) ligand binds in the -2 to +2 sites in both the wild-type and mutant enzymes. The glucosyl unit in the -1 site is distorted from the usual chair conformation in both structures. The IBXG ligand binds in the -2 to +1 sites, with the xylosyl unit in the -1 site where it adopts the energetically favourable chair conformation. The -1 site glucosyl of the (Glc)(2)-S-(Glc)(2) ligand is unable to take on this conformation because of steric clashes with the protein. The crystallographic results show that one of the tunnel-forming loops in Cel6A is sensitive to modifications at the active site, and is able to take on a number of different conformations. One of the conformational changes disrupts a set of interactions at the active site that we propose is an integral part of the reaction mechanism.
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Affiliation(s)
- J y Zou
- Department of Cell and Molecular Biology Uppsala University BMC Box 596, S-751 24, Uppsala, Sweden
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Varrot A, Hastrup S, Schülein M, Davies GJ. Crystal structure of the catalytic core domain of the family 6 cellobiohydrolase II, Cel6A, from Humicola insolens, at 1.92 A resolution. Biochem J 1999; 337 ( Pt 2):297-304. [PMID: 9882628 PMCID: PMC1219965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The three-dimensional structure of the catalytic core of the family 6 cellobiohydrolase II, Cel6A (CBH II), from Humicola insolens has been determined by X-ray crystallography at a resolution of 1.92 A. The structure was solved by molecular replacement using the homologous Trichoderma reesei CBH II as a search model. The H. insolens enzyme displays a high degree of structural similarity with its T. reesei equivalent. The structure features both O- (alpha-linked mannose) and N-linked glycosylation and a hexa-co-ordinate Mg2+ ion. The active-site residues are located within the enclosed tunnel that is typical for cellobiohydrolase enzymes and which may permit a processive hydrolysis of the cellulose substrate. The close structural similarity between the two enzymes implies that kinetics and chain-end specificity experiments performed on the H. insolens enzyme are likely to be applicable to the homologous T. reesei enzyme. These cast doubt on the description of cellobiohydrolases as exo-enzymes since they demonstrated that Cel6A (CBH II) shows no requirement for non-reducing chain-ends, as had been presumed. There is no crystallographic evidence in the present structure to support a mechanism involving loop opening, yet preliminary modelling experiments suggest that the active-site tunnel of Cel6A (CBH II) is too narrow to permit entry of a fluorescenyl-derivatized substrate, known to be a viable substrate for this enzyme.
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Affiliation(s)
- A Varrot
- Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York Y01 5DD, U.K
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Burmeister WP, Cottaz S, Driguez H, Iori R, Palmieri S, Henrissat B. The crystal structures of Sinapis alba myrosinase and a covalent glycosyl-enzyme intermediate provide insights into the substrate recognition and active-site machinery of an S-glycosidase. Structure 1997; 5:663-75. [PMID: 9195886 DOI: 10.1016/s0969-2126(97)00221-9] [Citation(s) in RCA: 227] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Myrosinase is the enzyme responsible for the hydrolysis of a variety of plant anionic 1-thio-beta-D-glucosides called glucosinolates. Myrosinase and glucosinolates, which are stored in different tissues of the plant, are mixed during mastication generating toxic by-products that are believed to play a role in the plant defence system. Whilst O-glycosidases are extremely widespread in nature, myrosinase is the only known S-glycosidase. This intriguing enzyme, which shows sequence similarities with O-glycosidases, offers the opportunity to analyze the similarities and differences between enzymes hydrolyzing S- and O-glycosidic bonds. RESULTS The structures of native myrosinase from white mustard seed (Sinapis alba) and of a stable glycosyl-enzyme intermediate have been solved at 1.6 A resolution. The protein folds into a (beta/alpha)8-barrel structure, very similar to that of the cyanogenic beta-glucosidase from white clover. The enzyme forms a dimer stabilized by a Zn2+ ion and is heavily glycosylated. At one glycosylation site the complete structure of a plant-specific heptasaccharide is observed. The myrosinase structure reveals a hydrophobic pocket, ideally situated for the binding of the hydrophobic sidechain of glucosinolates, and two arginine residues positioned for interaction with the sulphate group of the substrate. With the exception of the replacement of the general acid/base glutamate by a glutamine residue, the catalytic machinery of myrosinase is identical to that of the cyanogenic beta-glucosidase. The structure of the glycosyl-enzyme intermediate shows that the sugar ring is bound via an alpha-glycosidic linkage to Glu409, the catalytic nucleophile of myrosinase. CONCLUSIONS The structure of myrosinase shows features which illustrate the adaptation of the plant enzyme to the dehydrated environment of the seed. The catalytic mechanism of myrosinase is explained by the excellent leaving group properties of the substrate aglycons, which do not require the assistance of an enzymatic acid catalyst. The replacement of the general acid/base glutamate of O-glycosidases by a glutamine residue in myrosinase suggests that for hydrolysis of the glycosyl-enzyme, the role of this residue is to ensure a precise positioning of a water molecule rather than to provide general base assistance.
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Affiliation(s)
- W P Burmeister
- European Synchrotron Radiation Facility (ESRF), BP 220, F-38043 Grenoble cedex, France.
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Modes of action of two Trichoderma reesei cellobiohydrolases. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/s0921-0423(06)80105-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Affiliation(s)
- P Tomme
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
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Divne C, Ståhlberg J, Reinikainen T, Ruohonen L, Pettersson G, Knowles JK, Teeri TT, Jones TA. The three-dimensional crystal structure of the catalytic core of cellobiohydrolase I from Trichoderma reesei. Science 1994; 265:524-8. [PMID: 8036495 DOI: 10.1126/science.8036495] [Citation(s) in RCA: 411] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cellulose is the major polysaccharide of plants where it plays a predominantly structural role. A variety of highly specialized microorganisms have evolved to produce enzymes that either synergistically or in complexes can carry out the complete hydrolysis of cellulose. The structure of the major cellobiohydrolase, CBHI, of the potent cellulolytic fungus Trichoderma reesei has been determined and refined to 1.8 angstrom resolution. The molecule contains a 40 angstrom long active site tunnel that may account for many of the previously poorly understood macroscopic properties of the enzyme and its interaction with solid cellulose. The active site residues were identified by solving the structure of the enzyme complexed with an oligosaccharide, o-iodobenzyl-1-thio-beta-cellobioside. The three-dimensional structure is very similar to a family of bacterial beta-glucanases with the main-chain topology of the plant legume lectins.
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Affiliation(s)
- C Divne
- Department of Molecular Biology, Uppsala University, Sweden
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