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Romanò C, Bengtsson D, Infantino AS, Oscarson S. Synthesis of fluoro- and seleno-containing D-lactose and D-galactose analogues. Org Biomol Chem 2023; 21:2545-2555. [PMID: 36877217 DOI: 10.1039/d2ob02299k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Synthetic deoxy-fluoro-carbohydrate derivatives and seleno-sugars are useful tools in protein-carbohydrate interaction studies using nuclear magnetic resonance spectroscopy because of the presence of the 19F and 77Se reporter nuclei. Seven saccharides containing both these atoms have been synthesized, three monosaccharides, methyl 6-deoxy-6-fluoro-1-seleno-β-D-galactopyranoside (1) and methyl 2-deoxy-2-fluoro-1-seleno-α/β-D-galactopyranoside (2α and 2β), and four disaccharides, methyl 4-O-(β-D-galactopyranosyl)-2-deoxy-2-fluoro-1-seleno-β-D-glucopyranoside (3), methyl 4-Se-(β-D-galactopyranosyl)-2-deoxy-2-fluoro-4-seleno-β-D-glucopyranoside (4), and methyl 4-Se-(2-deoxy-2-fluoro-α/β-D-galactopyranosyl)-4-seleno-β-D-glucopyranoside (5α and 5β), the three latter compounds with an interglycosidic selenium atom. Selenoglycosides 1 and 3 were obtained from the corresponding bromo sugar by treatment with dimethyl selenide and a reducing agent, while compounds 2α/2β, 4, and 5α/5β were synthesized by the coupling of a D-galactosyl selenolate, obtained in situ from the corresponding isoselenouronium salt, with either methyl iodide or a 4-O-trifluoromethanesulfonyl D-galactosyl moiety. While benzyl ether protecting groups were found to be incompatible with the selenide linkage during deprotection, a change to acetyl esters afforded 4 in a 17% overall yield and over 9 steps from peracetylated D-galactosyl bromide. The synthesis of 5 was performed similarly, but the 2-fluoro substituent led to reduced stereoselectivity in the formation of the isoselenouronium salt (α/β ∼ 1 : 2.3). However, the β-anomer of the uronium salt could be obtained almost pure (∼98%) by precipitation from the reaction mixture. The following displacement reaction occurred without anomerisation, affording, after deacetylation, pure 5β.
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Affiliation(s)
- Cecilia Romanò
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Dennis Bengtsson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Angela Simona Infantino
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Stefan Oscarson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
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Raics M, Timári I, Szilágyi L, Gabius HJ, Kövér KE. Introducing 77Se NMR Spectroscopy to Analyzing Galectin -Ligand Interaction. Methods Mol Biol 2022; 2442:105-123. [PMID: 35320522 DOI: 10.1007/978-1-0716-2055-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Their emerging nature as multifunctional effectors explains the large interest to monitor glycan binding to galectins and to define bound-state conformer(s) of their ligands in solution. Basically, NMR spectroscopy facilitates respective experiments. Towards developing new and even better approaches for these purposes, extending the range of exploitable isotopes beyond 1H, 13C, and 15N offers promising perspectives. Having therefore prepared selenodigalactoside and revealed its bioactivity as galectin ligand, monitoring of its binding by 77Se NMR spectroscopy at a practical level becomes possible by setting up a 2D 1H, 77Se CPMG-HSQBMC experiment including CPMG-INEPT long-range transfer. This first step into applying 77Se as sensor for galectin binding substantiates its potential for screening relative to inhibitory potencies in compound mixtures and for achieving sophisticated epitope mapping. The documented strategic combination of synthetic carbohydrate chemistry and NMR spectroscopy prompts to envision to work with isotopically pure 77Se-containing β-galactosides and to build on the gained experience with 77Se by adding 19F as second sensor in doubly labeled glycosides.
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Affiliation(s)
- Mária Raics
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - István Timári
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - László Szilágyi
- Department of Organic Chemistry, University of Debrecen, Debrecen, Hungary
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany.
| | - Katalin E Kövér
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary.
- MTA-DE Molecular Recognition and Interaction Research Group, University of Debrecen, Debrecen, Hungary.
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3
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Diercks T, Medrano FJ, FitzGerald FG, Beckwith D, Pedersen MJ, Reihill M, Ludwig AK, Romero A, Oscarson S, Cudic M, Gabius HJ. Galectin-Glycan Interactions: Guidelines for Monitoring by 77 Se NMR Spectroscopy, and Solvent (H 2 O/D 2 O) Impact on Binding. Chemistry 2020; 27:316-325. [PMID: 32955737 PMCID: PMC7839768 DOI: 10.1002/chem.202003143] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/11/2020] [Indexed: 12/19/2022]
Abstract
Functional pairing between cellular glycoconjugates and tissue lectins like galectins has wide (patho)physiological significance. Their study is facilitated by nonhydrolysable derivatives of the natural O‐glycans, such as S‐ and Se‐glycosides. The latter enable extensive analyses by specific 77Se NMR spectroscopy, but still remain underexplored. By using the example of selenodigalactoside (SeDG) and the human galectin‐1 and ‐3, we have evaluated diverse 77Se NMR detection methods and propose selective 1H,77Se heteronuclear Hartmann–Hahn transfer for efficient use in competitive NMR screening against a selenoglycoside spy ligand. By fluorescence anisotropy, circular dichroism, and isothermal titration calorimetry (ITC), we show that the affinity and thermodynamics of SeDG binding by galectins are similar to thiodigalactoside (TDG) and N‐acetyllactosamine (LacNAc), confirming that Se substitution has no major impact. ITC data in D2O versus H2O are similar for TDG and LacNAc binding by both galectins, but a solvent effect, indicating solvent rearrangement at the binding site, is hinted at for SeDG and clearly observed for LacNAc dimers with extended chain length.
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Affiliation(s)
- Tammo Diercks
- NMR Facility, CiC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 800, 48160, Derio, Spain
| | - Francisco J Medrano
- Structural and Chemical Biology, Centro de Investigaciones, Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Forrest G FitzGerald
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Donella Beckwith
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Martin Jaeger Pedersen
- Center for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, 4, Ireland
| | - Mark Reihill
- Center for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, 4, Ireland
| | - Anna-Kristin Ludwig
- Tierärztliche Fakultät, Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Veterinärstr. 13, 80539, München, Germany
| | - Antonio Romero
- Structural and Chemical Biology, Centro de Investigaciones, Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Stefan Oscarson
- Center for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, 4, Ireland
| | - Maré Cudic
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Hans-Joachim Gabius
- Tierärztliche Fakultät, Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Veterinärstr. 13, 80539, München, Germany
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4
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Raics M, Timári I, Diercks T, Szilágyi L, Gabius H, Kövér KE. Selenoglycosides as Lectin Ligands: 77 Se-Edited CPMG-HSQMBC NMR Spectroscopy To Monitor Biomedically Relevant Interactions. Chembiochem 2019; 20:1688-1692. [PMID: 30828921 PMCID: PMC6618100 DOI: 10.1002/cbic.201900088] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Indexed: 12/25/2022]
Abstract
The fundamental importance of protein-glycan recognition calls for specific and sensitive high-resolution techniques for their detailed analysis. After the introduction of 19 F NMR spectroscopy to study the recognition of fluorinated glycans, a new 77 Se NMR spectroscopy method is presented for complementary studies of selenoglycans with optimised resolution and sensitivity, in which direct NMR spectroscopy detection on 77 Se is replaced by its indirect observation in a 2D 1 H,77 Se HSQMBC spectrum. In contrast to OH/F substitution, O/Se exchange allows the glycosidic bond to be targeted. As an example, selenodigalactoside recognition by three human galectins and a plant toxin is readily indicated by signal attenuation and line broadening in the 2D 1 H,77 Se HSQMBC spectrum, in which CPMG-INEPT long-range transfer ensures maximal detection sensitivity, clean signal phases, and reliable ligand ranking. By monitoring competitive displacement of a selenated spy ligand, the selective 77 Se NMR spectroscopy approach may also be used to screen non-selenated compounds. Finally, 1 H,77 Se CPMG-INEPT transfer allows further NMR sensors of molecular interaction to be combined with the specificity and resolution of 77 Se NMR spectroscopy.
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Affiliation(s)
- Mária Raics
- Department of Inorganic and Analytical ChemistryUniversity of DebrecenEgyetem tér 14032DebrecenHungary
| | - István Timári
- Department of Inorganic and Analytical ChemistryUniversity of DebrecenEgyetem tér 14032DebrecenHungary
| | - Tammo Diercks
- NMR FacilityCIC bioGUNEBizkaia Technology Park, Bld 80048170DerioSpain
| | - László Szilágyi
- Department of Organic ChemistryUniversity of DebrecenEgyetem tér 14032DebrecenHungary
| | - Hans‐Joachim Gabius
- Tierärztliche Fakultät, Institut für Physiologische ChemieLudwig-Maximilians-Universität MünchenVeterinärstrasse 1380539MunichGermany
| | - Katalin E. Kövér
- Department of Inorganic and Analytical ChemistryUniversity of DebrecenEgyetem tér 14032DebrecenHungary
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5
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Bivalent O -glycoside mimetics with S /disulfide/ Se substitutions and aromatic core: Synthesis, molecular modeling and inhibitory activity on biomedically relevant lectins in assays of increasing physiological relevance. Bioorg Med Chem 2017; 25:3158-3170. [DOI: 10.1016/j.bmc.2017.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 12/13/2022]
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6
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Multivalent Carbohydrate-Lectin Interactions: How Synthetic Chemistry Enables Insights into Nanometric Recognition. Molecules 2016; 21:molecules21050629. [PMID: 27187342 PMCID: PMC6274006 DOI: 10.3390/molecules21050629] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 05/02/2016] [Accepted: 05/10/2016] [Indexed: 12/15/2022] Open
Abstract
Glycan recognition by sugar receptors (lectins) is intimately involved in many aspects of cell physiology. However, the factors explaining the exquisite selectivity of their functional pairing are not yet fully understood. Studies toward this aim will also help appraise the potential for lectin-directed drug design. With the network of adhesion/growth-regulatory galectins as therapeutic targets, the strategy to recruit synthetic chemistry to systematically elucidate structure-activity relationships is outlined, from monovalent compounds to glyco-clusters and glycodendrimers to biomimetic surfaces. The versatility of the synthetic procedures enables to take examining structural and spatial parameters, alone and in combination, to its limits, for example with the aim to produce inhibitors for distinct galectin(s) that exhibit minimal reactivity to other members of this group. Shaping spatial architectures similar to glycoconjugate aggregates, microdomains or vesicles provides attractive tools to disclose the often still hidden significance of nanometric aspects of the different modes of lectin design (sequence divergence at the lectin site, differences of spatial type of lectin-site presentation). Of note, testing the effectors alone or in combination simulating (patho)physiological conditions, is sure to bring about new insights into the cooperation between lectins and the regulation of their activity.
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Pérez-Victoria I, Boutureira O, Claridge TDW, Davis BG. Glycosyldiselenides as lectin ligands detectable by NMR in biofluids. Chem Commun (Camb) 2016; 51:12208-11. [PMID: 26134709 DOI: 10.1039/c5cc03952e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The ability of glycosyldiselenides to act as lectin ligands and their selective detection in plasma by (77)Se NMR is reported.
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Affiliation(s)
- Ignacio Pérez-Victoria
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
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8
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McDonagh AW, Mahon MF, Murphy PV. Lewis Acid Induced Anomerization of Se-Glycosides. Application to Synthesis of α-Se-GalCer. Org Lett 2016; 18:552-5. [DOI: 10.1021/acs.orglett.5b03591] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Anthony W. McDonagh
- School
of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland
| | - Mary F. Mahon
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, United Kingdom
| | - Paul V. Murphy
- School
of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland
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9
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Abstract
The article reviews the significant contributions to, and the present status of, applications of computational methods for the characterization and prediction of protein-carbohydrate interactions. After a presentation of the specific features of carbohydrate modeling, along with a brief description of the experimental data and general features of carbohydrate-protein interactions, the survey provides a thorough coverage of the available computational methods and tools. At the quantum-mechanical level, the use of both molecular orbitals and density-functional theory is critically assessed. These are followed by a presentation and critical evaluation of the applications of semiempirical and empirical methods: QM/MM, molecular dynamics, free-energy calculations, metadynamics, molecular robotics, and others. The usefulness of molecular docking in structural glycobiology is evaluated by considering recent docking- validation studies on a range of protein targets. The range of applications of these theoretical methods provides insights into the structural, energetic, and mechanistic facets that occur in the course of the recognition processes. Selected examples are provided to exemplify the usefulness and the present limitations of these computational methods in their ability to assist in elucidation of the structural basis underlying the diverse function and biological roles of carbohydrates in their dialogue with proteins. These test cases cover the field of both carbohydrate biosynthesis and glycosyltransferases, as well as glycoside hydrolases. The phenomenon of (macro)molecular recognition is illustrated for the interactions of carbohydrates with such proteins as lectins, monoclonal antibodies, GAG-binding proteins, porins, and viruses.
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Affiliation(s)
- Serge Pérez
- Department of Molecular Pharmacochemistry, CNRS, University Grenoble-Alpes, Grenoble, France.
| | - Igor Tvaroška
- Department of Chemistry, Slovak Academy of Sciences, Bratislava, Slovak Republic; Department of Chemistry, Faculty of Natural Sciences, Constantine The Philosopher University, Nitra, Slovak Republic.
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10
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Thio- and selenoglycosides as ligands for biomedically relevant lectins: valency-activity correlations for benzene-based dithiogalactoside clusters and first assessment for (di)selenodigalactosides. Bioorg Med Chem Lett 2014; 25:931-5. [PMID: 25599835 DOI: 10.1016/j.bmcl.2014.12.049] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/10/2014] [Accepted: 12/12/2014] [Indexed: 01/26/2023]
Abstract
Substitution of the oxygen atom in the glycosidic linkage by a disulfide bond or by selenium makes the resulting glycoside resistant to hydrolysis. To clarify the consequences for affinity to lectins we prepared benzene-based mono- to trivalent dithiogalactosides. Inhibitory capacity increased with valency for a plant toxin, the synthetic compounds potently blocking its binding to a lactose-presenting matrix and to cells. Human galectins were much less sensitive to the disulfides than the toxin. This differential response constitutes a beneficial effect to avoid cross-reactivity in vivo. Symmetrical selenodigalactoside and diselenodigalactoside were prepared and similarly tested. Both compounds proved rather equally bioactive for the toxin, graded activity was measured for human galectins. This result directs attention to further studies to relate Se-dependent alterations in bond angle and length as well as van der Waals radius to binding properties of selenoglycosides to biomedically relevant lectins.
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11
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Hamark C, Landström J, Widmalm G. SEAL by NMR: Glyco‐Based Selenium‐Labeled Affinity Ligands Detected by NMR Spectroscopy. Chemistry 2014; 20:13905-8. [DOI: 10.1002/chem.201404933] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Indexed: 11/05/2022]
Affiliation(s)
- Christoffer Hamark
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, 10691 Stockholm (Sweden)
| | - Jens Landström
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, 10691 Stockholm (Sweden)
| | - Göran Widmalm
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, 10691 Stockholm (Sweden)
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12
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Solís D, Bovin NV, Davis AP, Jiménez-Barbero J, Romero A, Roy R, Smetana K, Gabius HJ. A guide into glycosciences: How chemistry, biochemistry and biology cooperate to crack the sugar code. Biochim Biophys Acta Gen Subj 2014; 1850:186-235. [PMID: 24685397 DOI: 10.1016/j.bbagen.2014.03.016] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 03/13/2014] [Accepted: 03/18/2014] [Indexed: 01/17/2023]
Abstract
BACKGROUND The most demanding challenge in research on molecular aspects within the flow of biological information is posed by the complex carbohydrates (glycan part of cellular glycoconjugates). How the 'message' encoded in carbohydrate 'letters' is 'read' and 'translated' can only be unraveled by interdisciplinary efforts. SCOPE OF REVIEW This review provides a didactic step-by-step survey of the concept of the sugar code and the way strategic combination of experimental approaches characterizes structure-function relationships, with resources for teaching. MAJOR CONCLUSIONS The unsurpassed coding capacity of glycans is an ideal platform for generating a broad range of molecular 'messages'. Structural and functional analyses of complex carbohydrates have been made possible by advances in chemical synthesis, rendering production of oligosaccharides, glycoclusters and neoglycoconjugates possible. This availability facilitates to test the glycans as ligands for natural sugar receptors (lectins). Their interaction is a means to turn sugar-encoded information into cellular effects. Glycan/lectin structures and their spatial modes of presentation underlie the exquisite specificity of the endogenous lectins in counterreceptor selection, that is, to home in on certain cellular glycoproteins or glycolipids. GENERAL SIGNIFICANCE Understanding how sugar-encoded 'messages' are 'read' and 'translated' by lectins provides insights into fundamental mechanisms of life, with potential for medical applications.
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Affiliation(s)
- Dolores Solís
- Instituto de Química Física "Rocasolano", CSIC, Serrano 119, 28006 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), 07110 Bunyola, Mallorca, Illes Baleares, Spain.
| | - Nicolai V Bovin
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul Miklukho-Maklaya 16/10, 117871 GSP-7, V-437, Moscow, Russian Federation.
| | - Anthony P Davis
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Jesús Jiménez-Barbero
- Chemical and Physical Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid, Spain.
| | - Antonio Romero
- Chemical and Physical Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid, Spain.
| | - René Roy
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Succ. Centre-Ville, Montréal, Québec H3C 3P8, Canada.
| | - Karel Smetana
- Charles University, 1st Faculty of Medicine, Institute of Anatomy, U nemocnice 3, 128 00 Prague 2, Czech Republic.
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Veterinärstr. 13, 80539 München, Germany.
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13
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Martín-Santamaría S, André S, Buzamet E, Caraballo R, Fernández-Cureses G, Morando M, Ribeiro JP, Ramírez-Gualito K, de Pascual-Teresa B, Cañada FJ, Menéndez M, Ramström O, Jiménez-Barbero J, Solís D, Gabius HJ. Symmetric dithiodigalactoside: strategic combination of binding studies and detection of selectivity between a plant toxin and human lectins. Org Biomol Chem 2011; 9:5445-55. [PMID: 21660340 DOI: 10.1039/c0ob01235a] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Thioglycosides offer the advantage over O-glycosides to be resistant to hydrolysis. Based on initial evidence of this recognition ability for glycosyldisulfides by screening dynamic combinatorial libraries, we have now systematically studied dithiodigalactoside on a plant toxin (Viscum album agglutinin) and five human lectins (adhesion/growth-regulatory galectins with medical relevance e.g. in tumor progression and spread). Inhibition assays with surface-presented neoglycoprotein and in solution monitored by saturation transfer difference NMR spectroscopy, flanked by epitope mapping, as well as isothermal titration calorimetry revealed binding properties to VAA (K(a): 1560 ± 20 M(-1)). They were reflected by the structural model and the affinity on the level of toxin-exposed cells. In comparison, galectins were considerably less reactive, with intrafamily grading down to very minor reactivity for tandem-repeat-type galectins, as quantitated by radioassays for both domains of galectin-4. Model building indicated contact formation to be restricted to only one galactose moiety, in contrast to thiodigalactoside. The tested glycosyldisulfide exhibits selectivity between the plant toxin and the tested human lectins, and also between these proteins. Therefore, glycosyldisulfides have potential as chemical platform for inhibitor design.
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Affiliation(s)
- Sonsoles Martín-Santamaría
- Departamento de Química, Facultad de Farmacia, Universidad San Pablo CEU, Boadilla del Monte, 28668, Madrid, Spain
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