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Wei X, Wang P, Liu F, Ye X, Xiong D. Drug Discovery Based on Fluorine-Containing Glycomimetics. Molecules 2023; 28:6641. [PMID: 37764416 PMCID: PMC10536126 DOI: 10.3390/molecules28186641] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Glycomimetics, which are synthetic molecules designed to mimic the structures and functions of natural carbohydrates, have been developed to overcome the limitations associated with natural carbohydrates. The fluorination of carbohydrates has emerged as a promising solution to dramatically enhance the metabolic stability, bioavailability, and protein-binding affinity of natural carbohydrates. In this review, the fluorination methods used to prepare the fluorinated carbohydrates, the effects of fluorination on the physical, chemical, and biological characteristics of natural sugars, and the biological activities of fluorinated sugars are presented.
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Affiliation(s)
- Xingxing Wei
- Department of Pharmacy, Changzhi Medical College, No. 161, Jiefang East Street, Changzhi 046012, China
| | - Pengyu Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. No. 38, Beijing 100191, China (F.L.); (X.Y.)
| | - Fen Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. No. 38, Beijing 100191, China (F.L.); (X.Y.)
| | - Xinshan Ye
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. No. 38, Beijing 100191, China (F.L.); (X.Y.)
| | - Decai Xiong
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. No. 38, Beijing 100191, China (F.L.); (X.Y.)
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2
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Abstract
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Fluorinated
carbohydrates have found many applications in the glycosciences.
Typically, these contain fluorination at a single position. There
are not many applications involving polyfluorinated carbohydrates,
here defined as monosaccharides in which more than one carbon has
at least one fluorine substituent directly attached to it, with the
notable exception of their use as mechanism-based inhibitors. The
increasing attention to carbohydrate physical properties, especially
around lipophilicity, has resulted in a surge of interest for this
class of compounds. This review covers the considerable body of work
toward the synthesis of polyfluorinated hexoses, pentoses, ketosugars,
and aminosugars including sialic acids and nucleosides. An overview
of the current state of the art of their glycosidation is also provided.
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Affiliation(s)
- Kler Huonnic
- School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, U.K
| | - Bruno Linclau
- School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, U.K.,Department of Organic and Macromolecular Chemistry, Ghent University, Campus Sterre, Krijgslaan 281-S4, Ghent, 9000, Belgium
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3
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Rowland RJ, Chen Y, Breen I, Wu L, Offen WA, Beenakker TJ, Su Q, van den Nieuwendijk AMCH, Aerts JMFG, Artola M, Overkleeft HS, Davies GJ. Design, Synthesis and Structural Analysis of Glucocerebrosidase Imaging Agents. Chemistry 2021; 27:16377-16388. [PMID: 34570911 PMCID: PMC9298352 DOI: 10.1002/chem.202102359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Indexed: 12/15/2022]
Abstract
Gaucher disease (GD) is a lysosomal storage disorder caused by inherited deficiencies in β‐glucocerebrosidase (GBA). Current treatments require rapid disease diagnosis and a means of monitoring therapeutic efficacy, both of which may be supported by the use of GBA‐targeting activity‐based probes (ABPs). Here, we report the synthesis and structural analysis of a range of cyclophellitol epoxide and aziridine inhibitors and ABPs for GBA. We demonstrate their covalent mechanism‐based mode of action and uncover binding of the new N‐functionalised aziridines to the ligand binding cleft. These inhibitors became scaffolds for the development of ABPs; the O6‐fluorescent tags of which bind in an allosteric site at the dimer interface. Considering GBA's preference for O6‐ and N‐functionalised reagents, a bi‐functional aziridine ABP was synthesized as a potentially more powerful imaging agent. Whilst this ABP binds to two unique active site clefts of GBA, no further benefit in potency was achieved over our first generation ABPs. Nevertheless, such ABPs should serve useful in the study of GBA in relation to GD and inform the design of future probes.
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Affiliation(s)
- Rhianna J Rowland
- Department of Chemistry, York Structural Biology Laboratory (YSBL), University of York Heslington, York, YO10 5DD, UK
| | - Yurong Chen
- Department of Bio-organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinwegg 55, 2300 RA, Leiden, Netherlands
| | - Imogen Breen
- Department of Chemistry, York Structural Biology Laboratory (YSBL), University of York Heslington, York, YO10 5DD, UK
| | - Liang Wu
- Department of Chemistry, York Structural Biology Laboratory (YSBL), University of York Heslington, York, YO10 5DD, UK
| | - Wendy A Offen
- Department of Chemistry, York Structural Biology Laboratory (YSBL), University of York Heslington, York, YO10 5DD, UK
| | - Thomas J Beenakker
- Department of Bio-organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinwegg 55, 2300 RA, Leiden, Netherlands
| | - Qin Su
- Department of Medicinal Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinwegg 55, 2300 RA, Leiden, Netherlands
| | | | - Johannes M F G Aerts
- Department of Medicinal Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinwegg 55, 2300 RA, Leiden, Netherlands
| | - Marta Artola
- Department of Medicinal Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinwegg 55, 2300 RA, Leiden, Netherlands
| | - Herman S Overkleeft
- Department of Bio-organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinwegg 55, 2300 RA, Leiden, Netherlands
| | - Gideon J Davies
- Department of Chemistry, York Structural Biology Laboratory (YSBL), University of York Heslington, York, YO10 5DD, UK
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4
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Khazaei K, Yeung JH, Moore MM, Bennet AJ. Inhibitory efficiencies for mechanism-based inactivators of sialidases. CAN J CHEM 2015. [DOI: 10.1139/cjc-2015-0245] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Here we describe the measurement of the inactivation rate constants for the mechanism-based inactivator 2,3-difluorosialic acid acting upon the sialidase from Micromonospora viridifaciens. Using double mixing stopped-flow experiments conducted in a 3-(N-morpholino)propanesulfonic acid buffer (100 mmol/L, pH 7.00) at 25 °C, the derived kinetic parameters are kinact/Ki = (3.9 ± 0.8) × 106 (mol/L)–1 s–1 and Ki = 1.7 ± 0.4 μmol/L. We demonstrate that the inhibitory efficiency of the inactivation event is similar to the catalytic efficiency for this sialidase acting upon a typical substrate, 4-methylumbelliferone α-d-sialoside, kcat/Km = (7.2 ± 2.8) × 106 (mol/L)–1 s–1. Furthermore, we show that the catalytic efficiencies for inactivation and hydrolysis by the Kdnase from Aspergillus fumigatus are similar for the corresponding Kdn-analogues. We conclude that the deactivating effect of incorporating an axial 3-fluoro substituent onto the sialic acid scaffold is comparable to the enhanced activation that occurs when the 4-methylumbelliferone leaving group is changed to the more nucleofugal fluoride ion.
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Affiliation(s)
- Kobra Khazaei
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Juliana H.F. Yeung
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Margo M. Moore
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Andrew J. Bennet
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
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5
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Kallemeijn WW, Witte MD, Wennekes T, Aerts JMFG. Mechanism-based inhibitors of glycosidases: design and applications. Adv Carbohydr Chem Biochem 2015; 71:297-338. [PMID: 25480507 DOI: 10.1016/b978-0-12-800128-8.00004-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This article covers recent developments in the design and application of activity-based probes (ABPs) for glycosidases, with emphasis on the different enzymes involved in metabolism of glucosylceramide in humans. Described are the various catalytic reaction mechanisms employed by inverting and retaining glycosidases. An understanding of catalysis at the molecular level has stimulated the design of different types of ABPs for glycosidases. Such compounds range from (1) transition-state mimics tagged with reactive moieties, which associate with the target active site—forming covalent bonds in a relatively nonspecific manner in or near the catalytic pocket—to (2) enzyme substrates that exploit the catalytic mechanism of retaining glycosidase targets to release a highly reactive species within the active site of the enzyme, to (3) probes based on mechanism-based, covalent, and irreversible glycosidase inhibitors. Some applications in biochemical and biological research of the activity-based glycosidase probes are discussed, including specific quantitative visualization of active enzyme molecules in vitro and in vivo, and as strategies for unambiguously identifying catalytic residues in glycosidases in vitro.
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Affiliation(s)
- Wouter W Kallemeijn
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Martin D Witte
- Department of Bio-Organic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands.
| | - Tom Wennekes
- Department of Synthetic Organic Chemistry, Wageningen University, Wageningen, The Netherlands.
| | - Johannes M F G Aerts
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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6
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Willems LI, Beenakker TJM, Murray B, Scheij S, Kallemeijn WW, Boot RG, Verhoek M, Donker-Koopman WE, Ferraz MJ, van Rijssel ER, Florea BI, Codée JDC, van der Marel GA, Aerts JMFG, Overkleeft HS. Potent and selective activity-based probes for GH27 human retaining α-galactosidases. J Am Chem Soc 2014; 136:11622-5. [PMID: 25105979 DOI: 10.1021/ja507040n] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lysosomal degradation of glycosphingolipids is mediated by the consecutive action of several glycosidases. Malfunctioning of one of these hydrolases can lead to a lysosomal storage disorder such as Fabry disease, which is caused by a deficiency in α-galactosidase A. Herein we describe the development of potent and selective activity-based probes that target retaining α-galactosidases. The fluorescently labeled aziridine-based probes 3 and 4 inhibit the two human retaining α-galactosidases αGal A and αGal B covalently and with high affinity. Moreover, they enable the visualization of the endogenous activity of both α-galactosidases in cell extracts, thereby providing a means to study the presence and location of active enzyme levels in different cell types, such as healthy cells versus those derived from Fabry patients.
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Affiliation(s)
- Lianne I Willems
- Leiden Institute of Chemistry and The Netherlands Proteomics Centre, Leiden University , P.O. Box 9502, 2300 RA Leiden, The Netherlands
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7
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Willems LI, Jiang J, Li KY, Witte MD, Kallemeijn WW, Beenakker TJN, Schröder SP, Aerts JMFG, van der Marel GA, Codée JDC, Overkleeft HS. From Covalent Glycosidase Inhibitors to Activity-Based Glycosidase Probes. Chemistry 2014; 20:10864-72. [DOI: 10.1002/chem.201404014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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8
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Barbosa HM, de Melo MM, Coimbra MA, Passos CP, Silva CM. Optimization of the supercritical fluid coextraction of oil and diterpenes from spent coffee grounds using experimental design and response surface methodology. J Supercrit Fluids 2014. [DOI: 10.1016/j.supflu.2013.11.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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9
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Hertz-Schünemann R, Dorfner R, Yeretzian C, Streibel T, Zimmermann R. On-line process monitoring of coffee roasting by resonant laser ionisation time-of-flight mass spectrometry: bridging the gap from industrial batch roasting to flavour formation inside an individual coffee bean. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:1253-1265. [PMID: 24338878 DOI: 10.1002/jms.3299] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/14/2013] [Accepted: 10/15/2013] [Indexed: 06/03/2023]
Abstract
Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOFMS) enables the fast and sensitive on-line monitoring of volatile organic compounds (VOC) formed during coffee roasting. On the one hand, REMPI-TOFMS was applied to monitor roasting gases of an industrial roaster (1500 kg/h capacity), with the aim of determining the roast degree in real-time from the transient chemical signature of VOCs. On the other hand, a previously developed μ-probe sampling device was used to analyse roasting gases from individual coffee beans. The aim was to explore fundamental processes at the individual bean level and link these to phenomena at the batch level. The pioneering single-bean experiments were conducted in two configurations: (1) VOCs formed inside a bean were sampled in situ, i.e. via a drilled μ-hole, from the interior, using a μ-probe (inside). (2) VOCs were sampled on-line in close vicinity of a single coffee bean's surface (outside). The focus was on VOCs originating from hydrolysis and pyrolytic degradation of chlorogenic acids, like feruloyl quinic acid and caffeoyl quinic acid. The single bean experiments revealed interesting phenomena. First, differences in time-intensity profiles between inside versus outside (time shift of maximum) were observed and tentatively linked to the permeability of the bean's cell walls material. Second, sharp bursts of some VOCs were observed, while others did exhibit smooth release curves. It is believed that these reflect a direct observation of bean popping during roasting. Finally, discrimination between Coffea arabica and Coffea canephora was demonstrated based on high-mass volatile markers, exclusively present in spectra of Coffea arabica.
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Affiliation(s)
- R Hertz-Schünemann
- Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, Institute of Chemistry, University of Rostock, D-18059, Rostock, Germany
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10
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Chemoenzymatic synthesis and lectin recognition of a selectively fluorinated glycoprotein. Bioorg Med Chem 2013; 21:4768-77. [PMID: 23566760 DOI: 10.1016/j.bmc.2013.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/25/2013] [Accepted: 03/06/2013] [Indexed: 11/22/2022]
Abstract
A chemoenzymatic glycosylation remodeling method for the synthesis of selectively fluorinated glycoproteins is described. The method consists of chemical synthesis of a fluoroglycan oxazoline and its use as donor substrate for endoglycosidase (ENGase)-catalyzed transglycosylation to a GlcNAc-protein to form a homogeneous fluoroglycoprotein. The approach was exemplified by the synthesis of fluorinated glycoforms of ribonuclease B (RNase B). An interesting finding was that fluorination at the C-6 of the 6-branched mannose moiety in the Man3GlcNAc core resulted in significantly enhanced reactivity of the substrate in enzymatic transglycosylation. A structural analysis suggests that the enhancement in reactivity may come from favorable hydrophobic interactions between the fluorine and a tyrosine residue in the catalytic site of the enzyme (Endo-A). SPR analysis of the binding of the fluorinated glycoproteins with lectin concanavalin A (con A) revealed the importance of the 6-hydroxyl group on the α-1,6-branched mannose moiety in con A recognition. The present study establishes a facile method for preparation of selectively fluorinated glycoproteins that can serve as valuable probes for elucidating specific carbohydrate-protein interactions.
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11
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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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12
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Witte MD, van der Marel GA, Aerts JMFG, Overkleeft HS. Irreversible inhibitors and activity-based probes as research tools in chemical glycobiology. Org Biomol Chem 2011; 9:5908-26. [DOI: 10.1039/c1ob05531c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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13
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The -galactosidase type A gene aglA from Aspergillus niger encodes a fully functional -N-acetylgalactosaminidase. Glycobiology 2010; 20:1410-9. [DOI: 10.1093/glycob/cwq105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Guce AI, Clark NE, Salgado EN, Ivanen DR, Kulminskaya AA, Brumer H, Garman SC. Catalytic mechanism of human alpha-galactosidase. J Biol Chem 2010; 285:3625-3632. [PMID: 19940122 PMCID: PMC2823503 DOI: 10.1074/jbc.m109.060145] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 11/06/2009] [Indexed: 11/06/2022] Open
Abstract
The enzyme alpha-galactosidase (alpha-GAL, also known as alpha-GAL A; E.C. 3.2.1.22) is responsible for the breakdown of alpha-galactosides in the lysosome. Defects in human alpha-GAL lead to the development of Fabry disease, a lysosomal storage disorder characterized by the buildup of alpha-galactosylated substrates in the tissues. alpha-GAL is an active target of clinical research: there are currently two treatment options for Fabry disease, recombinant enzyme replacement therapy (approved in the United States in 2003) and pharmacological chaperone therapy (currently in clinical trials). Previously, we have reported the structure of human alpha-GAL, which revealed the overall structure of the enzyme and established the locations of hundreds of mutations that lead to the development of Fabry disease. Here, we describe the catalytic mechanism of the enzyme derived from x-ray crystal structures of each of the four stages of the double displacement reaction mechanism. Use of a difluoro-alpha-galactopyranoside allowed trapping of a covalent intermediate. The ensemble of structures reveals distortion of the ligand into a (1)S(3) skew (or twist) boat conformation in the middle of the reaction cycle. The high resolution structures of each step in the catalytic cycle will allow for improved drug design efforts on alpha-GAL and other glycoside hydrolase family 27 enzymes by developing ligands that specifically target different states of the catalytic cycle. Additionally, the structures revealed a second ligand-binding site suitable for targeting by novel pharmacological chaperones.
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Affiliation(s)
- Abigail I Guce
- Departments of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003
| | - Nathaniel E Clark
- From the Departments of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003
| | - Eric N Salgado
- From the Departments of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003
| | - Dina R Ivanen
- the Molecular and Radiation Biophysics Division, Petersburg Nuclear Physics Institute, Russian Academy of Science, Orlova Roscha, Gatchina 188300, Leningrad District, Russia, and
| | - Anna A Kulminskaya
- the Molecular and Radiation Biophysics Division, Petersburg Nuclear Physics Institute, Russian Academy of Science, Orlova Roscha, Gatchina 188300, Leningrad District, Russia, and
| | - Harry Brumer
- the Department of Biotechnology, Royal Insitute of Technology (KTH), 10691 Stockholm, Sweden
| | - Scott C Garman
- Departments of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003; From the Departments of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003.
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15
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Clark NE, Garman SC. The 1.9 a structure of human alpha-N-acetylgalactosaminidase: The molecular basis of Schindler and Kanzaki diseases. J Mol Biol 2009; 393:435-47. [PMID: 19683538 PMCID: PMC2771859 DOI: 10.1016/j.jmb.2009.08.021] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/30/2009] [Accepted: 08/04/2009] [Indexed: 01/07/2023]
Abstract
alpha-N-acetylgalactosaminidase (alpha-NAGAL; E.C. 3.2.1.49) is a lysosomal exoglycosidase that cleaves terminal alpha-N-acetylgalactosamine residues from glycopeptides and glycolipids. In humans, a deficiency of alpha-NAGAL activity results in the lysosomal storage disorders Schindler disease and Kanzaki disease. To better understand the molecular defects in the diseases, we determined the crystal structure of human alpha-NAGAL after expressing wild-type and glycosylation-deficient glycoproteins in recombinant insect cell expression systems. We measured the enzymatic parameters of our purified wild-type and mutant enzymes, establishing their enzymatic equivalence. To investigate the binding specificity and catalytic mechanism of the human alpha-NAGAL enzyme, we determined three crystallographic complexes with different catalytic products bound in the active site of the enzyme. To better understand how individual defects in the alpha-NAGAL glycoprotein lead to Schindler disease, we analyzed the effect of disease-causing mutations on the three-dimensional structure.
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Affiliation(s)
- Nathaniel E Clark
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, 01003, USA
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16
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Weignerová L, Simerská P, Křen V. α-Galactosidases and their applications in biotransformations. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420802583416] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Berkowitz DB, Karukurichi KR, de la Salud-Bea R, Nelson DL, McCune CD. Use of Fluorinated Functionality in Enzyme Inhibitor Development: Mechanistic and Analytical Advantages. J Fluor Chem 2008; 129:731-742. [PMID: 19727327 PMCID: PMC2598403 DOI: 10.1016/j.jfluchem.2008.05.016] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
On the one hand, owing to its electronegativity, relatively small size, and notable leaving group ability from anionic intermediates, fluorine offers unique opportunities for mechanism-based enzyme inhibitor design. On the other, the "bio-orthogonal" and NMR-active 19-fluorine nucleus allows the bioorganic chemist to follow the mechanistic fate of fluorinated substrate analogues or inhibitors as they are enzymatically processed. This article takes an overview of the field, highlighting key developments along these lines. It begins by highlighting new screening methodologies for drug discovery that involve appropriate tagging of either substrate or the target protein itself with (19)F-markers, that then report back on turnover and binding, respectively, via an the NMR screen. Taking this one step further, substrate-tagging with fluorine can be done is such a manner as to provide stereochemical information on enzyme mechanism. For example, substitution of one of the terminal hydrogens in phosphoenolpyruvate, provides insight into the, otherwise latent, facial selectivity of C-C bond formation in KDO synthase. Perhaps, most importantly, from the point of view of this discussion, appropriately tailored fluorinated functionality can be used to form to stabilized "transition state analogue" complexes with a target enzymes. Thus, 5-fluorinated pyrimidines, alpha-fluorinated ketones, and 2-fluoro-2-deoxysugars each lead to covalent adduction of catalytic active site residues in thymidylate synthase, serine protease and glycosidase enzymes, respectively. In all such cases, (19)F NMR allows the bioorganic chemist to spectrally follow "transition state analogue" formation. Finally, the use of specific fluorinated functionality to engineer "suicide substrates" is highlighted in a discussion of the development of the alpha-(2'Z-fluoro)vinyl trigger for amino acid decarboxylase inactivation. Here (19)F NMR allows the bioorganic chemist to glean useful partition ratio data directly out of the NMR tube.
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Affiliation(s)
- David B Berkowitz
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304
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18
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Chevrier C, Defoin A, Tarnus C. Synthesis and evaluation of amino-threoses in d- and l-series: Are five membered ring amino-sugars more potent glycosidase inhibitors than the six membered ones? Bioorg Med Chem 2007; 15:4125-35. [PMID: 17434740 DOI: 10.1016/j.bmc.2007.03.073] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/18/2007] [Accepted: 03/23/2007] [Indexed: 11/18/2022]
Abstract
Cyclic D- and L-4-aminothreose were synthesised from ethyl D- and L-tartrate, respectively. D-aminothreose was a potent inhibitor of alpha-glucosidase and of alpha-mannosidase. From the glycosidase inhibition potencies of the four 4-amino-4-deoxy-tetroses, the contribution of binding of each functionality of the 5 and 6 membered ring amino-sugars towards the various glycosidases is discussed.
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Affiliation(s)
- Carine Chevrier
- Laboratoire de Chimie Organique et Bioorganique, UMR 7015, Ecole Nationale Supérieure de Chimie de Mulhouse, Université de Haute-Alsace, 3, rue Alfred Werner, F-68093 Mulhouse Cédex, France
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19
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Brouns SJJ, Smits N, Wu H, Snijders APL, Wright PC, de Vos WM, van der Oost J. Identification of a novel alpha-galactosidase from the hyperthermophilic archaeon Sulfolobus solfataricus. J Bacteriol 2006; 188:2392-9. [PMID: 16547025 PMCID: PMC1428385 DOI: 10.1128/jb.188.7.2392-2399.2006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sulfolobus solfataricus is an aerobic crenarchaeon that thrives in acidic volcanic pools. In this study, we have purified and characterized a thermostable alpha-galactosidase from cell extracts of S. solfataricus P2 grown on the trisaccharide raffinose. The enzyme, designated GalS, is highly specific for alpha-linked galactosides, which are optimally hydrolyzed at pH 5 and 90 degrees C. The protein consists of 74.7-kDa subunits and has been identified as the gene product of open reading frame Sso3127. Its primary sequence is most related to plant enzymes of glycoside hydrolase family 36, which are involved in the synthesis and degradation of raffinose and stachyose. Both the galS gene from S. solfataricus P2 and an orthologous gene from Sulfolobus tokodaii have been cloned and functionally expressed in Escherichia coli, and their activity was confirmed. At present, these Sulfolobus enzymes not only constitute a distinct type of thermostable alpha-galactosidases within glycoside hydrolase clan D but also represent the first members from the Archaea.
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Affiliation(s)
- Stan J J Brouns
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
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21
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Naumoff DG. GH97 is a new family of glycoside hydrolases, which is related to the alpha-galactosidase superfamily. BMC Genomics 2005; 6:112. [PMID: 16131397 PMCID: PMC1249566 DOI: 10.1186/1471-2164-6-112] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Accepted: 08/30/2005] [Indexed: 11/29/2022] Open
Abstract
Background As a rule, about 1% of genes in a given genome encode glycoside hydrolases and their homologues. On the basis of sequence similarity they have been grouped into more than ninety GH families during the last 15 years. The GH97 family has been established very recently and initially included only 18 bacterial proteins. However, the evolutionary relationship of the genes encoding proteins of this family remains unclear, as well as their distribution among main groups of the living organisms. Results The extensive search of the current databases allowed us to double the number of GH97 family proteins. Five subfamilies were distinguished on the basis of pairwise sequence comparison and phylogenetic analysis. Iterative sequence analysis revealed the relationship of the GH97 family with the GH27, GH31, and GH36 families of glycosidases, which belong to the α-galactosidase superfamily, as well as a more distant relationship with some other glycosidase families (GH13 and GH20). Conclusion The results of this study show an unexpected sequence similarity of GH97 family proteins with glycoside hydrolases from several other families, that have (β/α)8-barrel fold of the catalytic domain and a retaining mechanism of the glycoside bond hydrolysis. These data suggest a common evolutionary origin of glycosidases representing different families and clans.
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Affiliation(s)
- Daniil G Naumoff
- State Institute for Genetics and Selection of Industrial Microorganisms, I-Dorozhny proezd, 1, Moscow 117545, Russia.
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22
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Lovering AL, Lee SS, Kim YW, Withers SG, Strynadka NCJ. Mechanistic and structural analysis of a family 31 alpha-glycosidase and its glycosyl-enzyme intermediate. J Biol Chem 2004; 280:2105-15. [PMID: 15501829 DOI: 10.1074/jbc.m410468200] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have determined the first structure of a family 31 alpha-glycosidase, that of YicI from Escherichia coli, both free and trapped as a 5-fluoroxylopyranosyl-enzyme intermediate via reaction with 5-fluoro-alpha-D-xylopyranosyl fluoride. Our 2.2-A resolution structure shows an intimately associated hexamer with structural elements from several monomers converging at each of the six active sites. Our kinetic and mass spectrometry analyses verified several of the features observed in our structural data, including a covalent linkage from the carboxylate side chain of the identified nucleophile Asp(416) to C-1 of the sugar ring. Structure-based sequence comparison of YicI with the mammalian alpha-glucosidases lysosomal alpha-glucosidase and sucrase-isomaltase predicts a high level of structural similarity and provides a foundation for understanding the various mutations of these enzymes that elicit human disease.
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Affiliation(s)
- Andrew L Lovering
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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23
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Garman SC, Garboczi DN. The molecular defect leading to Fabry disease: structure of human alpha-galactosidase. J Mol Biol 2004; 337:319-35. [PMID: 15003450 DOI: 10.1016/j.jmb.2004.01.035] [Citation(s) in RCA: 284] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 01/16/2004] [Accepted: 01/21/2004] [Indexed: 01/01/2023]
Abstract
Fabry disease is an X-linked lysosomal storage disease afflicting 1 in 40,000 males with chronic pain, vascular degeneration, cardiac impairment, and other symptoms. Deficiency in the lysosomal enzyme alpha-galactosidase (alpha-GAL) causes an accumulation of its substrate, which ultimately leads to Fabry disease symptoms. Here, we present the structure of the human alpha-GAL glycoprotein determined by X-ray crystallography. The structure is a homodimer with each monomer containing a (beta/alpha)8 domain with the active site and an antiparallel beta domain. N-linked carbohydrate appears at six sites in the glycoprotein dimer, revealing the basis for lysosomal transport via the mannose-6-phosphate receptor. To understand how the enzyme cleaves galactose from glycoproteins and glycolipids, we also determined the structure of the complex of alpha-GAL with its catalytic product. The catalytic mechanism of the enzyme is revealed by the location of two aspartic acid residues (D170 and D231), which act as a nucleophile and an acid/base, respectively. As a point mutation in alpha-GAL can lead to Fabry disease, we have catalogued and plotted the locations of 245 missense and nonsense mutations in the three-dimensional structure. The structure of human alpha-GAL brings Fabry disease into the realm of molecular diseases, where insights into the structural basis of the disease phenotypes might help guide the clinical treatment of patients.
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Affiliation(s)
- Scott C Garman
- Structural Biology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Twinbrook II, 12441 Parklawn Drive, Rockville, MD 20852, USA.
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Tapernoux-Lüthi EM, Böhm A, Keller F. Cloning, functional expression, and characterization of the raffinose oligosaccharide chain elongation enzyme, galactan:galactan galactosyltransferase, from common bugle leaves. PLANT PHYSIOLOGY 2004; 134:1377-87. [PMID: 15034167 PMCID: PMC419815 DOI: 10.1104/pp.103.036210] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2003] [Revised: 12/23/2003] [Accepted: 01/19/2004] [Indexed: 05/17/2023]
Abstract
Galactan:galactan galactosyltransferase (GGT) is a unique enzyme of the raffinose family oligosaccharide (RFO) biosynthetic pathway. It catalyzes the chain elongation of RFOs without using galactinol (alpha-galactosyl-myoinositol) by simply transferring a terminal alpha-galactosyl residue from one RFO molecule to another one. Here, we report the cloning and functional expression of a cDNA encoding GGT from leaves of the common bugle (Ajuga reptans), a winter-hardy long-chain RFO-storing Lamiaceae. The cDNA comprises an open reading frame of 1215 bp. Expression in tobacco (Nicotiana plumbaginifolia) protoplasts resulted in a functional recombinant protein, which showed GGT activity like the previously described purified, native GGT enzyme. At the amino acid level, GGT shows high homologies (>60%) to acid plant alpha-galactosidases of the family 27 of glycosylhydrolases. It is clearly distinct from the family 36 of glycosylhydrolases, which harbor galactinol-dependent raffinose and stachyose synthases as well as alkaline alpha-galactosidases. Physiological studies on the role of GGT confirmed that GGT plays a key role in RFO chain elongation and carbon storage. When excised leaves were exposed to chilling temperatures, levels of GGT transcripts, enzyme activities, and long-chain RFO concentrations increased concomitantly. On a whole-plant level, chilling temperatures induced GGT expression mainly in the roots and fully developed leaves, both known RFO storage organs of the common bugle, indicating an adaptation of the metabolism from active growth to transient storage in the cold.
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Affiliation(s)
- Esther M Tapernoux-Lüthi
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
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25
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Cobucci-Ponzano B, Trincone A, Giordano A, Rossi M, Moracci M. Identification of the catalytic nucleophile of the family 29 alpha-L-fucosidase from Sulfolobus solfataricus via chemical rescue of an inactive mutant. Biochemistry 2003; 42:9525-31. [PMID: 12911294 DOI: 10.1021/bi035036t] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have recently reported that a functional alpha-L-fucosidase could be expressed by a single insertional mutation in the region of overlap between the ORFs SSO11867 and SSO3060 of the hyperthermophilic Archaeon Sulfolobus solfataricus [Cobucci-Ponzano et al. J. Biol. Chem. (2003) 278, 14622-14631]. This enzyme, belonging to glycoside hydrolase family 29 (GH29), showed micromolar specificity for p-nitrophenyl-alpha-L-fucoside (pNp-Fuc) and promoted transfucosylation reactions by following a reaction mechanism in which the products retained the anomeric configuration of the substrate. The active site residues in GH29 enzymes are still unknown. We describe here the identification of the catalytic nucleophile of the reaction in the alpha-L-fucosidase from S. solfataricus by reactivation with sodium azide of the mutant Asp242Gly that shows a 10(3)-fold activity reduction on pNp-Fuc. The detailed stereochemical analysis of the fucosyl-azide produced by the mutant reactivated on pNp-Fuc revealed its inverted (beta-fucosyl azide) configuration compared with the substrate. This allows for the first time the unambiguous assignment of Asp242, and its homologous residues, as the nucleophilic catalytic residues of GH29 alpha-L-fucosidases. This is the first time that this approach is used for alpha-L-glycosidases, widening the applicability of this method.
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Affiliation(s)
- Beatrice Cobucci-Ponzano
- Institute of Protein Biochemistry, Consiglio Nazionale delle Ricerche, Via P. Castellino 111, 80131, Naples, Italy
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Evers D, Ghislain M, Hausman JF, Dommes J. Differential gene expression in two potato lines differing in their resistance to Phytophthora infestans. JOURNAL OF PLANT PHYSIOLOGY 2003; 160:709-712. [PMID: 12872493 DOI: 10.1078/0176-1617-00908] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Horizontal resistance to late blight in the potato is a primary objective of many breeding programs. Knowledge of the physiological and biochemical mechanisms underlying it, however, is scarce. The purpose of the present study was the identification of these physiological and biochemical factors in plant material obtained by crossing a late blight resistant Solanum phureja clone with a susceptible dihaploid of S. tuberosum subsp. tuberosum. The mRNA RT-PCR differential display method was used to compare the gene expression patterns of a resistant hybrid with that of a susceptible one. By sequence homology, we identified several genes with diverse functions, including genes known to be involved in resistance or stress responses and genes known to be involved in primary or secondary metabolism.
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Affiliation(s)
- Danièle Evers
- CRP-Gabriel Lippmann, Cellule CREBS, 162A, avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg.
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Fujimoto Z, Kaneko S, Momma M, Kobayashi H, Mizuno H. Crystal structure of rice alpha-galactosidase complexed with D-galactose. J Biol Chem 2003; 278:20313-8. [PMID: 12657636 DOI: 10.1074/jbc.m302292200] [Citation(s) in RCA: 89] [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
alpha-Galactosidases catalyze the hydrolysis of alpha-1,6-linked galactosyl residues from galacto-oligosaccharides and polymeric galacto-(gluco)mannans. The crystal structure of rice alpha-galactosidase has been determined at 1.5A resolution using the multiple isomorphous replacement method. The structure consisted of a catalytic domain and a C-terminal domain and was essentially the same as that of alpha-N-acetylgalactosaminidase, which is the same member of glycosyl hydrolase family 27. The catalytic domain had a (beta/alpha)8-barrel structure, and the C-terminal domain was made up of eight beta-strands containing a Greek key motif. The structure was solved as a complex with d-galactose, providing a mode of substrate binding in detail. The d-galactose molecule was found bound in the active site pocket on the C-terminal side of the central beta-barrel of the catalytic domain. The d-galactose molecule consisted of a mixture of two anomers present in a ratio equal to their natural abundance. Structural comparisons of rice alpha-galactosidase with chicken alpha-N-acetylgalactosaminidase provided further understanding of the substrate recognition mechanism in these enzymes.
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Affiliation(s)
- Zui Fujimoto
- Department of Biochemistry, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
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Affiliation(s)
- Renée M Mosi
- AnorMED, Inc., Langley, British Columbia, Canada V2Y 1N5
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Abstract
The mechanism-based inactivation and subsequent identification of the nucleophilic residue using mass spectrometry have been successfully applied and used to identify the active-site nucleophile in numerous beta-glycosidases, as illustrated using C. fimi exoglycanase. Evidence for a covalent glycosyl-enzyme intermediate has come from X-ray crystallographic analysis of trapped complexes, the first being that of the trapped fluoroglycosyl-enzyme intermediate of Cex. The crystal structure of the trapped fluorocellobiosyl-enzyme complex for Cex has provided useful insights into catalysis and the roles of specific residues at the active site. In addition, information about the conformation of the natural sugar in the covalently bound state and the interactions at the active site was obtained using a mutant form of Cex.
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Affiliation(s)
- Jacqueline Wicki
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
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Czifrák K, Somsák L. Radical-mediated bromination of carbohydrate derivatives: searching for alternative reaction conditions without carbon tetrachloride. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)02205-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
The three-dimensional structure of glycosidases and of their complexes and the study of transition-state mimics reveal structural details that correlate with mechanism. Of particular interest are the transition-state conformations harnessed by individual enzymes and the substrate distortion observed in enzyme-ligand complexes. 3D-structure in synergy with transition-state mimicry opens the way for mechanistic interpretation of enzyme inhibition and for the development of therapeutic agents.
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Affiliation(s)
- Andrea Vasella
- Laboratorium für Organische Chemie, ETH Hönggerberg, HCI H317, CH-8093 Zürich, Switzerland
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Garman SC, Hannick L, Zhu A, Garboczi DN. The 1.9 A structure of alpha-N-acetylgalactosaminidase: molecular basis of glycosidase deficiency diseases. Structure 2002; 10:425-34. [PMID: 12005440 DOI: 10.1016/s0969-2126(02)00726-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the lysosome, glycosidases degrade glycolipids, glycoproteins, and oligosaccharides. Mutations in glycosidases cause disorders characterized by the deposition of undegraded carbohydrates. Schindler and Fabry diseases are caused by the incomplete degradation of carbohydrates with terminal alpha-N-acetylgalactosamine and alpha-galactose, respectively. Here we present the X-ray structure of alpha-N-acetylgalactosaminidase (alpha-NAGAL), the glycosidase that removes alpha-N-acetylgalactosamine, and the structure with bound ligand. The active site residues of alpha-NAGAL are conserved in the closely related enzyme a-galactosidase A (alpha-GAL). The structure demonstrates the catalytic mechanisms of both enzymes and reveals the structural basis of mutations causing Schindler and Fabry diseases. As alpha-NAGAL and alpha-GAL produce type O "universal donor" blood from type A and type B blood, the alpha-NAGAL structure will aid in the engineering of improved enzymes for blood conversion.
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Affiliation(s)
- Scott C Garman
- Structural Biology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA.
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Shabalin KA, Kulminskaya AA, Savel’ev AN, Shishlyannikov SM, Neustroev KN. Enzymatic properties of α-galactosidase from Trichoderma reesei in the hydrolysis of galactooligosaccharides. Enzyme Microb Technol 2002. [DOI: 10.1016/s0141-0229(01)00482-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Peterbauer T, Mucha J, Mach L, Richter A. Chain Elongation of raffinose in pea seeds. Isolation, characterization, and molecular cloning of mutifunctional enzyme catalyzing the synthesis of stachyose and verbascose. J Biol Chem 2002; 277:194-200. [PMID: 11675396 DOI: 10.1074/jbc.m109734200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Raffinose oligosaccharides are major soluble carbohydrates in seeds and other tissues of plants. Their biosynthesis proceeds by stepwise addition of galactose units to sucrose, which are provided by the unusual donor galactinol (O-alpha-d-galactopyranosyl-(1-->1)-l-myo-inositol). Chain elongation may also proceed by transfer of galactose units between raffinose oligosaccharides. We here report on the purification, characterization, and heterologous expression of a multifunctional stachyose synthase (EC ) from developing pea (Pisum sativum L.) seeds. The protein, a member of family 36 of glycoside hydrolases, catalyzes the synthesis of stachyose, the tetrasaccharide of the raffinose series, by galactosyl transfer from galactinol to raffinose. It also mediates the synthesis of the pentasaccharide verbascose by galactosyl transfer from galactinol to stachyose as well as by self-transfer of the terminal galactose residue from one stachyose molecule to another. These activities show optima at pH 7.0. The enzyme also catalyzes hydrolysis of the terminal galactose residue of its substrates, but is unable to initiate the synthesis of raffinose oligosaccharides by galactosyl transfer from galactinol to sucrose. A minimum reaction mechanism which accounts for the broad substrate specificity and the steady-state kinetic properties of the protein is presented.
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Affiliation(s)
- Thomas Peterbauer
- Institute of Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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Lee SS, He S, Withers SG. Identification of the catalytic nucleophile of the Family 31 alpha-glucosidase from Aspergillus niger via trapping of a 5-fluoroglycosyl-enzyme intermediate. Biochem J 2001; 359:381-6. [PMID: 11583585 PMCID: PMC1222157 DOI: 10.1042/0264-6021:3590381] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The mechanism-based reagent 5-fluoro-alpha-d-glucopyranosyl fluoride (5F alpha GlcF) was used to trap a glycosyl-enzyme intermediate and identify the catalytic nucleophile at the active site of Aspergillus niger alpha-glucosidase (Family 31). Incubation of the enzyme with 5F alpha GlcF, followed by peptic proteolysis and comparative liquid chromatography/MS mapping allowed the isolation of a labelled peptide. Fragmentation analysis of this peptide by tandem MS yielded the sequence WYDMSE, with the label located on the aspartic acid residue (D). Comparison with the known protein sequence identified the labelled amino acid as Asp-224 of the P2 subunit.
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Affiliation(s)
- S S Lee
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada V6T 1Z1
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