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Courjol F, Jouault T, Mille C, Hall R, Maes E, Sendid B, Mallet JM, Guerardel Y, Gow NAR, Poulain D, Fradin C. β-1,2-Mannosyltransferases 1 and 3 Participate in Yeast and Hyphae O- and N-Linked Mannosylation and Alter Candida albicans Fitness During Infection. Open Forum Infect Dis 2015; 2:ofv116. [PMID: 26389126 PMCID: PMC4564806 DOI: 10.1093/ofid/ofv116] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 08/11/2015] [Indexed: 11/19/2022] Open
Abstract
β-1,2-mannosylation of Candida albicans glycoconjugates has been investigated through the identification of enzymes involved in the addition of β-1,2-oligomannosides (β-Mans) to phosphopeptidomannan and phospholipomannan. β-1,2-oligomannosides are supposed to have virulence properties that they confer to these glycoconjugates. In a previous study, we showed that cell wall mannoproteins (CWMPs) harbor β-Mans in their O-mannosides; therefore, we analyzed their biosynthesis and impact on virulence. In this study, we demonstrate that O-mannans are heterogeneous and that α-mannosylated O-mannosides, which are biosynthesized by Mnt1 and Mnt2 α-1,2-mannosyltransferases, can be modified with β-Mans but only at the nonreducing end of α-1,2-mannotriose. β-1,2-mannosylation of this O-mannotriose depends on growth conditions, and it involves 2 β-1,2-mannosyltransferases, Bmt1 and Bmt3. These Bmts are essential for β-1,2-mannosylation of CWMPs and expression of β-Mans on germ tubes. A bmt1Δ mutant and a mutant expressing no β-Mans unexpectedly disseminated more in BALB/c mice, whereas they had neither attenuated nor enhanced virulence in C57BL/6 mice. In galectin (Gal)3 knockout mice, the reference strain was more virulent than in C57BL/6 mice, suggesting that the β-Mans innate receptor Gal3 is involved in C. albicans fitness during infection.
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Affiliation(s)
- Flavie Courjol
- Université de Lille ; Institut National de la Santé et de la Recherche Médicale, Lille Inflammation Research International Center-Unité Mixte de Recherche 995 , France
| | - Thierry Jouault
- Université de Lille ; Institut National de la Santé et de la Recherche Médicale, Lille Inflammation Research International Center-Unité Mixte de Recherche 995 , France
| | - Céline Mille
- Université de Lille ; Institut National de la Santé et de la Recherche Médicale, Lille Inflammation Research International Center-Unité Mixte de Recherche 995 , France
| | - Rebecca Hall
- Aberdeen Fungal Group, School of Medical Sciences , Institute of Medical Sciences , University of Aberdeen , Foresterhill , United Kingdom
| | - Emmanuel Maes
- Université de Lille , Unité de Glycobiologie Structurale et Fonctionnelle ; Centre National de la Recherche Scientifique , Unité Mixte de Recherche 8576 , Villeneuve d'Ascq
| | - Boualem Sendid
- Université de Lille ; Institut National de la Santé et de la Recherche Médicale, Lille Inflammation Research International Center-Unité Mixte de Recherche 995 , France ; Centre Hospitalier Régional Universitaire de Lille, Centre Biologie et Pathologie
| | - Jean Maurice Mallet
- Laboratoire des Biomolécules Unité Mixte de Recherche 7203 , Université Pierre et Marie Curie, Ecole Normale Supérieure , Paris , France
| | - Yann Guerardel
- Université de Lille , Unité de Glycobiologie Structurale et Fonctionnelle ; Centre National de la Recherche Scientifique , Unité Mixte de Recherche 8576 , Villeneuve d'Ascq
| | - Neil A R Gow
- Aberdeen Fungal Group, School of Medical Sciences , Institute of Medical Sciences , University of Aberdeen , Foresterhill , United Kingdom
| | - Daniel Poulain
- Université de Lille ; Institut National de la Santé et de la Recherche Médicale, Lille Inflammation Research International Center-Unité Mixte de Recherche 995 , France ; Centre Hospitalier Régional Universitaire de Lille, Centre Biologie et Pathologie
| | - Chantal Fradin
- Université de Lille ; Institut National de la Santé et de la Recherche Médicale, Lille Inflammation Research International Center-Unité Mixte de Recherche 995 , France
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2
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Humbert L, Maubert MA, Wolf C, Duboc H, Mahé M, Farabos D, Seksik P, Mallet JM, Trugnan G, Masliah J, Rainteau D. Bile acid profiling in human biological samples: comparison of extraction procedures and application to normal and cholestatic patients. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 899:135-45. [PMID: 22664055 DOI: 10.1016/j.jchromb.2012.05.015] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 04/30/2012] [Accepted: 05/09/2012] [Indexed: 02/08/2023]
Abstract
The role of bile acids in cell metabolism, membrane biology and cell signaling is increasingly recognized, thus making necessary a robust and versatile technique to extract, separate and quantify a large concentration range of these numerous molecular species. HPLC-MS/MS analysis provides the highest sensitivity to detect and identify bile acids. However, due to their large chemical diversity, extraction methods are critical and quite difficult to optimize, as shown by a survey of the literature. This paper compares the performances of four bile acid extraction protocols applied to either liquid (serum, urine, bile) or solid (stool) samples. Acetonitrile was found to be the best solvent for deproteinizing liquid samples and NaOH the best one for stool extraction. These optimized extraction procedures allowed us to quantitate as much as 27 distinct bile acids including sulfated species in a unique 30 min HPLC run, including both hydrophilic and hydrophobic species with a high efficiency. Tandem MS provided a non ambiguous identification of each metabolite with a good sensitivity (LOQ below 20 nmol/l except for THDCA and TLCA). After validation, these methods, successfully applied to a group of 39 control patients, detected 14 different species in serum in the range of 30-800 nmol/l, 11 species in urine in the range of 20-200 nmol/l and 25 species in stool in the range of 0.4-2000 nmol/g. The clinical interest of this method has been then validated on cholestatic patients. The proposed protocols seem suitable for profiling bile acids in routine analysis.
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Affiliation(s)
- Lydie Humbert
- ERL INSERM U 1057/UMR 7203, Université Pierre et Marie Curie, Paris, France
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3
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Laurent N, Lafont D, Boullanger P, Mallet JM. An alternative high yielding and highly stereoselective method for preparing an α-Neu5NAc-(2,6)-d-GalN3 building block suitable for further glycosylation. Carbohydr Res 2005; 340:1885-92. [PMID: 15963962 DOI: 10.1016/j.carres.2005.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 05/25/2005] [Accepted: 05/26/2005] [Indexed: 11/22/2022]
Abstract
This paper deals with new approaches to alpha-Neu5NAc-(2,6)-D-GalN3 building blocks, suitable as glycosylation donors. The major improvement, by comparison with the results of the literature, lies in the glycosylation step of a new d-galactosamine acceptor (tert-butyldimethylsilyl 3-O-acetyl-2-azido-2-deoxy-beta-D-galactopyranoside) with O-methyl-S-[methyl(5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-alpha-D-galacto-non-2-ulopyranosyl)onate] dithiocarbonate as the N-acetylneuraminic acid donor. The reaction affords the expected disaccharide in high yield (85%) and a complete alpha-Neu5NAc stereoselectivity. A subsequent oxidation step, eliminating the glycal by-product allows an easier purification. Afterwards, the tert-butyldimethylsilyl disaccharide can be transformed into a donor, after cleavage of the anomeric group in smooth conditions.
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Affiliation(s)
- Nicolas Laurent
- Laboratoire de Chimie Organique II-Glycochimie, Unité Mixte de Recherche CNRS 5181, Université Lyon 1, Chimie Physique Electronique de Lyon, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France
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4
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Dalle F, Jouault T, Trinel PA, Esnault J, Mallet JM, d'Athis P, Poulain D, Bonnin A. Beta-1,2- and alpha-1,2-linked oligomannosides mediate adherence of Candida albicans blastospores to human enterocytes in vitro. Infect Immun 2004; 71:7061-8. [PMID: 14638796 PMCID: PMC308904 DOI: 10.1128/iai.71.12.7061-7068.2003] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida albicans is a commensal dimorphic yeast of the digestive tract that causes hematogenously disseminated infections in immunocompromised individuals. Endogenous invasive candidiasis develops from C. albicans adhering to the intestinal epithelium. Adherence is mediated by the cell wall surface, a domain composed essentially of mannopyranosyl residues bound to proteins, the N-linked moiety of which comprises sequences of alpha-1,2- and beta-1,2-linked mannose residues. Beta-1,2-linked mannosides are also associated with a glycolipid, phospholipomannan, at the C. albicans surface. In order to determine the roles of beta-1,2 and alpha-1,2 oligomannosides in the C. albicans-enterocyte interaction, we developed a model of adhesion of C. albicans VW32 blastospores to the apical regions of differentiated Caco-2 cells. Preincubation of yeasts with monoclonal antibodies (MAbs) specific for alpha-1,2 and beta-1,2 mannan epitopes resulted in a dose-dependent decrease in adhesion (50% of the control with a 60- micro g/ml MAb concentration). In competitive assays beta-1,2 and alpha-1,2 tetramannosides were the most potent carbohydrate inhibitors, with 50% inhibitory concentrations of 2.58 and 6.99 mM, respectively. Immunolocalization on infected monolayers with MAbs specific for alpha-1,2 and beta-1,2 oligomannosides showed that these epitopes were shed from the yeast to the enterocyte surface. Taken together, our data indicate that alpha-1,2 and beta-1,2 oligomannosides are involved in the C. albicans-enterocyte interaction and participate in the adhesion of the yeasts to the mucosal surface.
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Affiliation(s)
- Fredéric Dalle
- Laboratoire de Parasitologie Mycologie, Hôpital du Bocage, Dijon, France
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5
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Dromer F, Chevalier R, Sendid B, Improvisi L, Jouault T, Robert R, Mallet JM, Poulain D. Synthetic analogues of beta-1,2 oligomannosides prevent intestinal colonization by the pathogenic yeast Candida albicans. Antimicrob Agents Chemother 2002; 46:3869-76. [PMID: 12435690 PMCID: PMC132753 DOI: 10.1128/aac.46.12.3869-3876.2002] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2002] [Revised: 05/13/2002] [Accepted: 07/15/2002] [Indexed: 11/20/2022] Open
Abstract
The pathogenic yeast Candida albicans displays at its cell surface beta-1,2 oligomannosides (beta-1,2-Mans). In contrast to the ubiquitous alpha-Mans, beta-1,2-Mans bind to galectin-3, a major endogenous lectin expressed on epithelial cells. The specific role of beta-1,2-Mans in colonization of the gut by C. albicans was assessed in a mouse model. A selected virulent strain of C. albicans (expressing more beta-1,2-Man epitopes) induced more intense and sustained colonization than an avirulent strain (expressing less beta-1,2-Man epitopes). Synthetic (Sigma) beta-and alpha-linked tetramannosides with antigenicities that mimicked the antigenicities of C. albicans-derived oligomannosides were then constructed. Oral administration of Sigmabeta-1,2-Man (30 mg/kg of body weight) prior to inoculation with the virulent strain resulted in almost complete eradication of yeasts from stool samples, whereas administration of Sigmaalpha-Man at the same dose did not. As most cases of human systemic candidiasis are endogenous in origin, this first demonstration that a synthetic analogue of a yeast adhesin can prevent yeast colonization in the gut opens the possibility of new prophylactic strategies.
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Affiliation(s)
- Françoise Dromer
- Unité de Mycologie Moléculaire, Institut Pasteur, 75015 Paris, France
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6
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Das SK, Mallet JM, Esnault J, Driguez PA, Duchaussoy P, Sizun P, Herault JP, Herbert JM, Petitou M, Sinaÿ P. Synthesis of conformationally locked L-iduronic acid derivatives: direct evidence for a critical role of the skew-boat 2S0 conformer in the activation of antithrombin by heparin. Chemistry 2001; 7:4821-34. [PMID: 11763451 DOI: 10.1002/1521-3765(20011119)7:22<4821::aid-chem4821>3.0.co;2-n] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We have used organic synthesis to understand the role of L-iduronic acid conformational flexibility in the activation of antithrombin by heparin. Among known synthetic analogues of the genuine pentasaccharidic sequence representing the antithrombin binding site of heparin, we have selected as a reference compound the methylated anti-factor Xa pentasaccharide 1. As in the genuine original fragment, the single L-iduronic acid moiety of this molecule exists in water solution as an equilibrium between three conformers 1C4, 4C1 and 2S0. We have thus synthesized three analogues of 1, in which the L-iduronic acid unit is locked in one of these three fixed conformations. A covalent two atom bridge between carbon atoms two and five of L-iduronic acid was first introduced to lock the pseudorotational itinerary of the pyranoid ring around the 2S0 form. A key compound to achieve this connection was the D-glucose derivative 5 in which the H-5 hydrogen atom has been replaced by a vinyl group, which is a progenitor of the carboxylic acid. Selective manipulations of this molecule resulted in the 2S0-type pentasaccharide 23. Starting from the D-glucose derivative 28, a covalent two atom bridge was now built up between carbon atoms three and five to lock the L-iduronic acid moiety around the 1C4 chair form conformation, and the 1C4-type pentasaccharide 43 was synthesized. Finally the L-iduronic acid containing disaccharide 58 which, due to the presence of the methoxymethyl substituent at position five adopts a 4C1 conformation, was directly used to synthesize the 4C1-type pentasaccharide 61. The locked pentasaccharide 23 showed about the same activity as the reference compound 1 in an antithrombin-mediated anti-Xa assay, whereas the two pentasaccharides 43 and 61 displayed very low activity. These results clearly establish the critical importance of the 2S0 conformation of L-iduronic acid in the activation of antithrombin by heparin.
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Affiliation(s)
- S K Das
- Ecole Normale Supérieure, Département de Chimie Associé au CNRS, Paris, France
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7
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Abstract
Carbohydrate-carbohydrate interactions are rarely considered in biologically relevant situations such as cell recognition and adhesion. One Ca(2+)-mediated homotypic interaction between two Lewis(x) determinants (Le(x)) has been proposed to drive cell adhesion in murine embryogenesis. Here, we confirm the existence of this specific interaction by reporting the first direct quantitative measurements in an environment akin to that provided by membranes. The adhesion between giant vesicles functionalized with Le(x) was obtained by micropipette aspiration and contact angle measurements. This interaction is below the thermal energy, and cell-cell adhesion will require a large number of molecules, as illustrated by the Le(x) concentration peak observed at the cell membranes during the morula stage of the embryo. This adhesion is ultralow and therefore difficult to measure. Such small interactions explain why the concept of specific interactions between carbohydrates is often neglected.
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Affiliation(s)
- F Pincet
- Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550 associée au CNRS et aux Universités Paris 6 et Paris 7, 75231 Paris cedex 05, France
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8
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Abstract
Triisobutylaluminum-promoted rearrangement of unsaturated glycosides containing electron-donating aglycons-such as C-aryl glycoside 1, or O-, S-, and Se-glycosides-provides direct access to highly functionalized cyclohexane derivatives such as 2.
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Affiliation(s)
- M Sollogoub
- Département de Chimie Associé au CNRS, Ecole Normale Supérieure 24 rue Lhomond, 75231 Paris cedex 05 (France)
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9
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Bregant S, Zhang Y, Mallet JM, Brodzki A, Sinaÿ P. Synthesis of a highly hydrophobic dimeric Lewis X containing glycolipid: a model for the study of homotypic carbohydrate--carbohydrate interaction. Glycoconj J 1999; 16:757-65. [PMID: 11133015 DOI: 10.1023/a:1007115528216] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This paper describes the synthesis of an octasaccharidic glycolipid 1 based on a stereo- and regioselective glycosylation between a Lewis X trisaccharidic donor and a pentasaccharidic acceptor. A highly hydrophobic lipid moiety of a new type was selected, making the compound 1 a good candidate for the study of the interaction of Lewis X functionalised vesicles.
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Affiliation(s)
- S Bregant
- Ecole Normale Supérieure, Département de Chimie, CNRS UMR 8642, Paris, France
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10
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Tabeur C, Mallet JM, Bono F, Herbert JM, Petitou M, Sinaÿ P. Oligosaccharides corresponding to the regular sequence of heparin: chemical synthesis and interaction with FGF-2. Bioorg Med Chem 1999; 7:2003-12. [PMID: 10530949 DOI: 10.1016/s0968-0896(99)00113-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It has been proposed that oligosaccharides corresponding to the so-called regular region of heparin/heparan sulfate (HS) bind to fibroblast growth factor-2 (FGF-2). In order to explore the molecular basis of FGF/HS interaction, we describe here the chemical synthesis of a tetra and a hexasaccharide, prepared as methyl glycosides, corresponding to the regular sequence of heparin. The strategy relies on the efficient preparation of three building blocks: a seeding block, an elongating block and a capping block. The hexasaccharide inhibited the binding of FGF-2 on its receptor on human aorta vascular smooth muscle cells with an IC50 value (16+/-1.2 microg/mL) close to that of standard heparin (14.8+/-0.5 microg/mL) whereas the tetrasaccharide was much less potent (IC50 = 127+/-10.5 microg/mL). The hexasaccharide and heparin, inhibited in a dose-dependent manner FGF-2 (30 nM) induced proliferation (IC50 = 23.7+/-1.6 and 30.1+/-1.3 microg/mL, respectively). Under the same experimental conditions, the tetrasaccharide only slightly inhibited the mitogenic effect of FGF-2 (IC50 > 100 microg/mL).
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Affiliation(s)
- C Tabeur
- Ecole Normale Supérieure, Département de Chimie, Associé au CNRS, Paris, France
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11
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Henry B, Desvaux H, Pristchepa M, Berthault P, Zhang YM, Mallet JM, Esnault J, Sinaÿ P. NMR study of a Lewis(X) pentasaccharide derivative: solution structure and interaction with cations. Carbohydr Res 1999; 315:48-62. [PMID: 10385972 DOI: 10.1016/s0008-6215(98)00301-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure and conformation of the synthetic pentasaccharide Gal(beta 1-4){Fuc(alpha 1-3)}GlcNAc(beta 1-3)Gal(beta 1-4)Glc-beta OMe of the Lewis(X) family has been determined by NMR spectroscopy in dimethyl sulfoxide and methanol. In these solvents, the binding constants with calcium have been evaluated as 9.5 and 29.6 M-1, respectively. Study of the interaction sites has been achieved through the use of paramagnetic divalent cations and distance triangulation methods. Two regions have been found, the first one in the vicinity of the fucose unit, the second one closer to the lactose part.
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Affiliation(s)
- B Henry
- CEA Saclay, Laboratoire Commun de RMN, DSM/DRECAM/SCM, Gif sur Yvette, France
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12
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Petitou M, Hérault JP, Lormeau JC, Helmboldt A, Mallet JM, Sinaÿ P, Herbert JM. Introducing a C-interglycosidic bond in a biologically active pentasaccharide hardly affects its biological properties. Bioorg Med Chem 1998; 6:1509-16. [PMID: 9801822 DOI: 10.1016/s0968-0896(98)00094-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We describe here the synthesis and the biological activity of a 'C-pentasaccharide', a new analogue of the antithrombin III (AT III) binding region of heparin containing a methylene bridge in place of an interglycosidic oxygen atom. The affinity for AT III and the anti-factor Xa activity of this compound have been compared with that of the corresponding selected 'O-pentasaccharide'. Such a structural modification slightly decreased the affinity of this compound for AT III as well as its anti-factor Xa activity (880 +/- 40 anti-Xa units versus 1180 +/- 30 anti-Xa units for the C-pentasaccharide and the O-pentasaccharide, respectively). This compound therefore represents the first example of a new class of anti-factor Xa pentasaccharides containing a C-interglycosidic bond.
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Affiliation(s)
- M Petitou
- Haemobiology Research Department, Sanofi Recherche, Toulouse, France
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13
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Lei PS, Duchaussoy P, Sizun P, Mallet JM, Petitou M, Sinaÿ P. Synthesis of a 3-deoxy-L-iduronic acid containing heparin pentasaccharide to probe the conformation of the antithrombin III binding sequence. Bioorg Med Chem 1998; 6:1337-46. [PMID: 9784873 DOI: 10.1016/s0968-0896(98)00127-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We report in this work the total synthesis of a close analogue of the pentasaccharide active site of heparin, in which the L-iduronic acid residue has been deoxygenated at position three. 1H NMR studies demonstrated that, as anticipated, such a modification induces a shift of the conformational equilibrium toward 1C4 (contribution to the conformational equilibrium rises from 37% to 65%) and a substantial decrease of the affinity for antithrombin III (Kd 0.154 microM versus 0.050 microM).
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Affiliation(s)
- P S Lei
- Ecole Normale Supérieure, Département de Chimie, URA CNRS 1686, Paris, France
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14
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Bornaghi L, Utille JP, Mallet JM, Sinaÿ P, Driguez H. Transfer reactions catalyzed by cyclodextrin glucosyltransferase using 4-thiomaltosyl and C-maltosyl fluorides as artificial donors. Carbohydr Res 1997; 305:561-8. [PMID: 9648273 DOI: 10.1016/s0008-6215(97)00262-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cyclodextrin glycosyltransferase enzyme from Bacillus circulans catalyzed the effective conversion of 4-thio-alpha-maltosyl fluoride into cyclo-alpha-(1-->4(2))-thiomalto -tetraoside, -pentaoside, -hexaoside and linear hemithiomaltooligosaccharides. However, under the same conditions, C-maltosyl fluoride afforded only linear modified maltotetraose, maltohexaose and maltooctaose in moderate yield.
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Affiliation(s)
- L Bornaghi
- Centre de Recherches sur les Macromolécules Végétales, (CERMAV-CNRS), Grenoble, France
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15
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Fradin C, Jouault T, Mallet A, Mallet JM, Camus D, Sinaÿ P, Poulain D. Beta-1,2-linked oligomannosides inhibit Candida albicans binding to murine macrophage. J Leukoc Biol 1996; 60:81-7. [PMID: 8699128 DOI: 10.1002/jlb.60.1.81] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Interaction of Candida albicans with cells of the macrophage lineage was examined by using heat-killed (HK) and live yeast cells. Laminarin, an analogue of the cell wall beta-glucans, strongly inhibited HK yeasts adherence to J774 cell line but had no effect on live yeast binding. Phosphopeptidomannan (PPM) from Saccharomyces cerevisiae had a limited effect on the binding of both HK and live yeasts but significant inhibition was achieved by the use of C. albicans PPM. The role of beta-1,2-oligomannosides was examined with regard to their exclusive presence within C. albicans PPM. PPM acid labile beta-1,2-oligomannosides or a synthetic beta-1,2-mannotetraose, inhibited yeasts binding in a manner comparable to the original PPM. These latter results were confirmed by using mouse peritoneal macrophages, thus suggesting a general role for beta-1,2-oligomannosides in the adherence of the yeast to the macrophage membrane.
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Affiliation(s)
- C Fradin
- Unité INSERM 42, Domaine du CERTIA, Villeneuve d'Ascq, France
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16
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Abstract
O-[Methyl (2-O-acetyl-3-O-benzyl-4-O-levulinyl-alpha, and beta-L-idopyranosid)uronate] trichloroacetimidate and the corresponding n-pentenyl glycosides are efficient L-iduronic acid glycosyl donors. Both have been used for the high-yielding synthesis of basic disaccharide blocks which are useful for the subsequent synthesis of complex oligosaccharides related to heparin/heparan sulfate, and dermatan sulfate. In contrast, the corresponding thioethyl glycosides, thiophenyl glycosides, and fluoride, did not yield the expected disaccharides.
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Affiliation(s)
- C Tabeur
- Département de Chimie, URA CNRS 1686, Paris, France
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17
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Abstract
Constant current electrolyses of the glycosyl donors phenyl and ethyl 2,3,4,6-tetra-O-benzyl-1-thio-beta-D-glucopyranoside in dry acetonitrile in the presence of various primary and secondary sugar alcohols, performed in an undivided cell, gave beta-linked disaccharide derivatives selectively in good yields. Phenyl 2,3,4,6-tetra-O-benzoyl-1-thio-beta-D-glucopyranoside gave the beta-glucosides exclusively in good to moderate yields.
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Affiliation(s)
- J M Mallet
- Ecole Normale Supérieure, Laboratoire de Chimie, U.R.A. 1110, Paris, France
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Zhang YM, Mallet JM, Sinaÿ P. Glycosylation using a one-electron-transfer, homogeneous reagent. Application to an efficient synthesis of the trimannosyl core of N-glycosylproteins. Carbohydr Res 1992; 236:73-88. [PMID: 1291063 DOI: 10.1016/0008-6215(92)85007-m] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Double glycosylation of methyl 2,4-di-O-benzyl-beta-D-mannopyranoside with ethyl 2-O-benzoyl-3,4,6-tri-O-benzyl-1-thio-alpha-D-mannopyranoside using as promoter tris(4-bromophenyl)ammoniumyl hexachloroantimonate, a stable, commercial, and crystalline radical cation, afforded after debenzoylation methyl 2,4-di-O-benzyl-3,6-di-O-(3,4,6-tri-O-benzyl-alpha-D-mannopyranoside in excellent yield. Other mannosyl donors were also investigated.
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Affiliation(s)
- Y M Zhang
- Ecole Normale Supérieure, Laboratoire de Chimie, U.R.A. 1110, Paris, France
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