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Zumbro E, Alexander-Katz A. Polymer Stiffness Regulates Multivalent Binding and Liquid-Liquid Phase Separation. Biophys J 2020; 119:1849-1864. [PMID: 33091341 DOI: 10.1016/j.bpj.2020.09.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/18/2020] [Accepted: 09/17/2020] [Indexed: 01/06/2023] Open
Abstract
Multivalent binding is essential to many biological processes because it builds high-affinity bonds by using several weak binding interactions simultaneously. Multivalent polymers have shown promise as inhibitors of toxins and other pathogens, and they are important components in the formation of biocondensates. Explaining how structural features of these polymers change their binding and subsequent control of phase separation is critical to designing better pathogen inhibitors and also to understanding diseases associated with membraneless organelles. In this work, we will examine the binding of a multivalent polymer to a small target. This scenario could represent a polymeric inhibitor binding to a toxic protein or RNA binding to an RNA-binding protein in the case of liquid-liquid phase separation. We use simulation and theory to show that flexible random-coil polymers bind more strongly than stiff rod-like polymers and that flexible polymers nucleate condensed phases at lower binding energies than their rigid analogs. We hope these results will provide insight into the rational design of polymeric inhibitors and improve our understanding of phase separation in cells and membraneless organelles.
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Affiliation(s)
- Emiko Zumbro
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Alfredo Alexander-Katz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts.
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2
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Zumbro E, Alexander-Katz A. Influence of Binding Site Affinity Patterns on Binding of Multivalent Polymers. ACS OMEGA 2020; 5:10774-10781. [PMID: 32455197 PMCID: PMC7240832 DOI: 10.1021/acsomega.0c00334] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 04/16/2020] [Indexed: 05/09/2023]
Abstract
Using inspiration from biology, we can leverage multivalent binding interactions to enhance weak, monovalent binding between molecules. While most previous studies have focused on multivalent binders with uniform binding sites, new synthetic polymers might find it desirable to have multiple binding moieties along the chain. Here, we probe how patterning of heterogeneous binding sites along a polymer chain controls the binding affinity of a polymer using a reactive Brownian dynamics scheme. Unlike monovalent binders that are pattern-agnostic, we find that divalent binding is dependent on both the polymer pattern and binding target concentration. For dilute targets, blocky polymers provide high local concentrations of high-affinity sites, but at high target concentrations, competition for binding sites makes alternating polymers the strongest binders. Subsequently, we show that random copolymers are robust to target concentration fluctuations. These results will assist in the rational design of multivalent polymer therapeutics and materials.
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Affiliation(s)
- Emiko Zumbro
- Department of Materials Science
and Engineering, Massachusetts Institute
of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Alfredo Alexander-Katz
- Department of Materials Science
and Engineering, Massachusetts Institute
of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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3
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Zumbro E, Witten J, Alexander-Katz A. Computational Insights into Avidity of Polymeric Multivalent Binders. Biophys J 2019; 117:892-902. [PMID: 31400918 PMCID: PMC6731389 DOI: 10.1016/j.bpj.2019.07.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/24/2019] [Accepted: 07/17/2019] [Indexed: 11/28/2022] Open
Abstract
Multivalent binding interactions are commonly found throughout biology to enhance weak monovalent binding such as between glycoligands and protein receptors. Designing multivalent polymers to bind to viruses and toxic proteins is a promising avenue for inhibiting their attachment and subsequent infection of cells. Several studies have focused on oligomeric multivalent inhibitors and how changing parameters such as ligand shape, size, linker length, and flexibility affect binding. However, experimental studies of how larger structural parameters of multivalent polymers, such as degree of polymerization, affect binding avidity to targets have mixed results, with some finding an improvement with longer polymers and some finding no effect. Here, we use Brownian dynamics simulations to provide a theoretical understanding of how the degree of polymerization affects the binding avidity of multivalent polymers. We show that longer polymers increase binding avidity to multivalent targets but reach a limit in binding avidity at high degrees of polymerization. We also show that when interacting with multiple targets simultaneously, longer polymers are able to use intertarget interactions to promote clustering and improve binding efficiency. We expect our results to narrow the design space for optimizing the structure and effectiveness of multivalent inhibitors as well as be useful to understand biological design strategies for multivalent binding.
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Affiliation(s)
- Emiko Zumbro
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Jacob Witten
- Computational and Systems Biology Initiative, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Alfredo Alexander-Katz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts.
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4
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Gupta N, Jangid AK, Singh M, Pooja D, Kulhari H. Designing Two-Dimensional Nanosheets for Improving Drug Delivery to Fucose-Receptor-Overexpressing Cancer Cells. ChemMedChem 2018; 13:2644-2652. [PMID: 30371024 DOI: 10.1002/cmdc.201800575] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/15/2018] [Indexed: 02/06/2023]
Abstract
Targeted drug delivery has shown promise in improving the therapeutic efficacy of anticancer drugs. Gemcitabine hydrochloride (GEM) is a broad-range chemotherapeutic agent for the treatment of various cancers. However, systemic use of free GEM is restricted because of its poor physicochemical properties and nonspecific drug delivery, resulting in dose-dependent adverse effects. In this study, a fucose-conjugated graphene oxide (GO)-based smart targeted nanocarrier system was designed to provide high loading, sustained release, and targeted high concentrations of GEM to cancer cells. Fucose-conjugated GO nanosheets (FGONS) and GEM-loaded fucose-conjugated GO nanosheets (GEM-FGONS) were prepared and characterized by various techniques. About 36.2 % of GEM was loaded to the FGONS, which showed a pH-dependent release over a period of 48 h. A colloidal suspension of GEM-FGONS was found to be physiochemically stable for up to 96 h. In cytotoxicity studies, GEM-FGONS demonstrated time- and dose-dependent high toxicities on fucose-receptor-overexpressing MDA-MB-231 human breast cancer cells and A549 human lung cancer cells. Moreover, targeted formulations were more efficacious than non-targeted or free GEM. Overall, bioconjugation of fucose helps in the stabilizing and targeting of graphene oxide nanosheets.
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Affiliation(s)
- Nitin Gupta
- School of Nano Sciences, Central University of Gujarat, Sector 30, Gandhinagar, Gujarat, 382030, India
| | - Ashok Kumar Jangid
- School of Nano Sciences, Central University of Gujarat, Sector 30, Gandhinagar, Gujarat, 382030, India
| | - Mandeep Singh
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
| | - Deep Pooja
- Applied Biology Division, CSIR - Indian Institute of Chemical Technology, Hyderabad, Telangana, 500007, India
| | - Hitesh Kulhari
- School of Nano Sciences, Central University of Gujarat, Sector 30, Gandhinagar, Gujarat, 382030, India
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5
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Tang J, Ozhegov E, Liu Y, Wang D, Yao X, Sun XL. Straightforward Synthesis of N-Glycan Polymers from Free Glycans via Cyanoxyl Free Radical-Mediated Polymerization. ACS Macro Lett 2017; 6:107-111. [PMID: 35632901 DOI: 10.1021/acsmacrolett.6b00928] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We report a straightforward synthesis of N-glycan polymers from free glycans via glycosylamine intermediates followed by acrylation and polymerization via cyanoxyl-mediated free radical polymerization (CMFRP) in one-pot fashion. No protection and deprotection were used in either glycomonomer or glycopolymer synthesis. A typical synthetic procedure for N-glycan polymers from free monosaccharide and disaccharide, Glc, Gal, Man, GlcNAc, and Lac, was demonstrated. In addition, enzymatic sialylation of the Lac-containing N-glycan polymers and their anti-influenza virus hemagglutination activities were investigated.
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Affiliation(s)
- Jinshan Tang
- Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Jinan University, West 601, Huangpu Avenue, Guangzhou, People’s Republic of China
| | - Evgeny Ozhegov
- Department
of Chemistry, Chemical and Biomedical Engineering and Center for Gene
Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115, United States
| | - Yang Liu
- Key
Laboratory of Structure-Based Drugs Design and Discovery of Ministry
of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, People’s Republic of China
| | - Dan Wang
- Department
of Chemistry, Chemical and Biomedical Engineering and Center for Gene
Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115, United States
| | - Xinsheng Yao
- Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Jinan University, West 601, Huangpu Avenue, Guangzhou, People’s Republic of China
| | - Xue-Long Sun
- Department
of Chemistry, Chemical and Biomedical Engineering and Center for Gene
Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115, United States
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6
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Ogata M, Chuma Y, Yasumoto Y, Onoda T, Umemura M, Usui T, Park EY. Synthesis of tetravalent LacNAc-glycoclusters as high-affinity cross-linker against Erythrina cristagalli agglutinin. Bioorg Med Chem 2015; 24:1-11. [PMID: 26672510 DOI: 10.1016/j.bmc.2015.11.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 11/17/2015] [Accepted: 11/20/2015] [Indexed: 12/22/2022]
Abstract
Four kinds of tetravalent double-headed glycoclusters [(LacNAc)4-DHGs] were designed with linkers of varying lengths consisting of alkanedioic carboxyamido groups (C6, C12, C18 and C24) between two bi-antennary LacNAc-glycosides. These glycoclusters served as high-affinity cross-linking ligands for the LacNAc-binding lectin Erythrina cristagalli agglutinin (ECA). The binding activity and cross-linking between each ligand and ECA were characterized by a hemagglutination inhibition (HI) assay, isothermal titration calorimetry (ITC), a quantitative precipitation assay and dynamic light scattering (DLS). For the precipitation assay and DLS measurement, the synthesized (LacNAc)4-DHGs were found to be capable of binding and precipitating the ECA as multivalent ligands. ITC analysis indicated the binding of (LacNAc)4-DHGs was driven by a favorable enthalpy change. Furthermore, the entropy penalty from binding (LacNAc)4-DHGs clearly decreased in a spacer length-dependent manner. The binding affinities of flexible (LacNAc)4-DHGs (C18 and C24) with long spacers were found to be more favorable than those of the clusters having short spacers (C6 and C12). These results were supported by molecular dynamics simulations with explicit water molecules for the tetravalent glycoclusters with ECA. We concluded that the subtle modification in the epitope-presenting scaffolds exerts the significant effect in the recognition efficiency involved in the LacNAc moieties by ECA.
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Affiliation(s)
- Makoto Ogata
- Department of Chemistry and Biochemistry, National Institute of Technology, Fukushima College, 30 Nagao, Iwaki, Fukushima 970-8034, Japan.
| | - Yasushi Chuma
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Yoshinori Yasumoto
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Takashi Onoda
- Department of Chemistry and Biochemistry, National Institute of Technology, Fukushima College, 30 Nagao, Iwaki, Fukushima 970-8034, Japan
| | - Myco Umemura
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan
| | - Taichi Usui
- Integrated Bioscience Research Division, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Enoch Y Park
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan; Integrated Bioscience Research Division, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan; Research Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
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7
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Affiliation(s)
- Yoshiko Miura
- Department of Chemical Engineering, Graduate
School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yu Hoshino
- Department of Chemical Engineering, Graduate
School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hirokazu Seto
- Department of Chemical Engineering, Graduate
School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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8
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Abstract
This article highlights the very recent advances in glycopolypeptide synthesis via NCA polymerization and first studies on stimuli-responsive solution behavior and self-assembling structures. Yet glycopolypeptides are almost exclusively considered as smart biofunctional materials for use in biomedical applications, for instance in targeted drug delivery, but also have high potential for usage as structural materials to fabricate bioinspired hierarchical structures.
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Affiliation(s)
- Kai-Steffen Krannig
- Max Planck Institute of Colloids and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424 Potsdam, Germany.
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9
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Krannig KS, Doriti A, Schlaad H. Facilitated Synthesis of Heterofunctional Glycopolypeptides. Macromolecules 2014. [DOI: 10.1021/ma500379m] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Kai-Steffen Krannig
- Max Planck
Institute of Colloids
and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424 Potsdam, Germany
| | - Afroditi Doriti
- Max Planck
Institute of Colloids
and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424 Potsdam, Germany
| | - Helmut Schlaad
- Max Planck
Institute of Colloids
and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424 Potsdam, Germany
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10
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Bonduelle C, Lecommandoux S. Synthetic Glycopolypeptides as Biomimetic Analogues of Natural Glycoproteins. Biomacromolecules 2013; 14:2973-83. [DOI: 10.1021/bm4008088] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Colin Bonduelle
- Université de Bordeaux/IPB, ENSCBP, 16 avenue Pey Berland, 33607
Pessac Cedex, France
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11
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Mildner R, Menzel H. Facile synthesis of pH-responsive glycopolypeptides with adjustable sugar density. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/pola.26796] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Robert Mildner
- Institute for Technical Chemistry, University of Technology Braunschweig; Hans-Sommer-Str. 10 38106 Braunschweig Germany
| | - Henning Menzel
- Institute for Technical Chemistry, University of Technology Braunschweig; Hans-Sommer-Str. 10 38106 Braunschweig Germany
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12
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Ghadban A, Albertin L, Moussavou Mounguengui RW, Peruchon A, Heyraud A. Synthesis of β-d-glucopyranuronosylamine in aqueous solution: kinetic study and synthetic potential. Carbohydr Res 2011; 346:2384-93. [DOI: 10.1016/j.carres.2011.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 08/16/2011] [Accepted: 08/18/2011] [Indexed: 10/17/2022]
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13
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Ghadban A, Albertin L, Condamine E, Mounguengui RWM, Heyraud A. NMR and MS study of the formation of β-d-glucopyranosylamine uronic acid in aqueous solution. CAN J CHEM 2011. [DOI: 10.1139/v11-064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The products of the reaction of d-glucuronic acid with various combinations of ammonia and volatile ammonium salts in water were studied by NMR and MS spectroscopy. For long reaction times (~24 h), the expected products β-d-glucopyranosylamine uronic acid and ammonium N-(β-d-glucopyranosyluronic acid)carbamate were obtained in good-to-high yield, whereas seven intermediate species were identified in samples taken at earlier reaction times. 1H–1H homonuclear and 1H–13C heteronuclear correlation experiments enabled a complete assignment of the 1H and 13C NMR spectra of the starting and final compounds, and a partial assignment of the peaks of intermediate species. Based on these results, a 1H NMR protocol for the quantification of the different compounds taking part in the reaction was developed, which was used to monitor the evolution of the composition of an early reaction sample redissolved in D2O. It was thus established that two of the observed intermediate species are actually the α anomer of the main products, whereas the others are precursors to the formation of α/β-d-glucopyranosylamine uronic acid and ammonium N-(α/β-d-glucopyranosyluronic acid)carbamate. The correct assignments for the 1H and 13C spectra of d-glucuronic acid in D2O are also reported.
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Affiliation(s)
- Ali Ghadban
- Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP53, 38041 Grenoble CEDEX 9, France
| | - Luca Albertin
- Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP53, 38041 Grenoble CEDEX 9, France
| | - Eric Condamine
- Institut de Biologie Structurale “Jean-Pierre Ebel”, UMR5075 (CEA/CNRS/UJF), 41 rue Jules Horowitz, 38027 Grenoble, France
| | | | - Alain Heyraud
- Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP53, 38041 Grenoble CEDEX 9, France
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14
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Gautier FM, Djedaïni-Pilard F, Grandjean C. The iodosulfonamidation of peracetylated glycals revisited: access to 1,2-di-nitrogenated sugars. Carbohydr Res 2011; 346:577-87. [DOI: 10.1016/j.carres.2011.01.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 01/17/2011] [Accepted: 01/20/2011] [Indexed: 01/21/2023]
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15
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Molecular design of N-linked tetravalent glycosides bearing N-acetylglucosamine, N,N′-diacetylchitobiose and N-acetyllactosamine: Analysis of cross-linking activities with WGA and ECA lectins. Bioorg Med Chem 2010; 18:621-9. [DOI: 10.1016/j.bmc.2009.12.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 12/01/2009] [Accepted: 12/02/2009] [Indexed: 11/19/2022]
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16
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Ting SRS, Chen G, Stenzel MH. Synthesis of glycopolymers and their multivalent recognitions with lectins. Polym Chem 2010. [DOI: 10.1039/c0py00141d] [Citation(s) in RCA: 321] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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17
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Polizzotti BD, Maheshwari R, Vinkenborg J, Kiick KL. Effects of Saccharide Spacing and Chain Extension on Toxin Inhibition by Glycopolypeptides of Well-Defined Architecture. Macromolecules 2007; 40:7103-7110. [PMID: 19169374 PMCID: PMC2629637 DOI: 10.1021/ma070725o] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many recognition events important in biology are mediated via multivalent interactions between relevant oligosaccharides and multiple saccharide receptors present on lectins, viruses, toxins, and cell surfaces. Because of the important role played by protein-carbohydrate interactions in these pathogenic recognition events and in other human diseases, considerable effort has been devoted toward the development of multivalent polymeric ligands for carbohydrate-binding proteins. In this work, we report the synthesis of new polypeptide-based glycopolymers produced via a combination of protein engineering and chemical methods. These methodologies permit control over the number and the spacing of saccharides on the scaffold, as well as the conformation of the polymer backbone, and allow a more purposeful design of polymers for manipulation of multivalent binding events. Two families of galactose-bearing glycopolypeptides with random coil conformations, [(AG)(3)PEG](y) (y = 10 and 16) and {[(AG)(2)PSG](2)[(AG)(2)PEG][(AG)(2)PSG](2)}(y) (y = 6), have been synthesized. The carboxylic acid functionality of the glutamic acid residues allowed subsequent modification with amino-saccharides to yield the desired glycopolypeptides; selective placement of the glutamic acid group permitted investigation of the effects of multivalency and saccharide spacing on toxin inhibition. In addition, a family of galactose-functionalized PGA-based glycopolymers of varying molecular weights was also synthesized to compare the effects of backbone flexibility and hydrodynamic volume, relative to the recombinant glycopolypeptides, on toxin inhibition. Glycopolypeptides were characterized via (1)H NMR, MALDI-TOF mass spectrometry, SDS-PAGE analysis, and spectrophotometric assays. They were tested as inhibitors of the binding of the cholera toxin B subunit via direct enzyme-linked assays. The data from these experiments confirm the relevance of appropriate saccharide spacing on controlling the binding event and also indicate the influence of chain extension in improving inhibition.
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Affiliation(s)
- Brian D Polizzotti
- Department of Materials Science and Engineering and Delaware Biotechnology Institute, University of Delaware, 201 DuPont Hall, Newark, Delaware 19716
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18
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Polizzotti BD, Kiick KL. Effects of polymer structure on the inhibition of cholera toxin by linear polypeptide-based glycopolymers. Biomacromolecules 2006; 7:483-90. [PMID: 16471920 PMCID: PMC2657727 DOI: 10.1021/bm050672n] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A variety of important biological events are mediated by the multivalent interaction between relevant oligosaccharides and multiple saccharide receptors on lectins, toxins, and cell surfaces; a variety of glycopolymeric materials have therefore been investigated in studies aimed at manipulating these events. The synthesis of protein- and polypeptide-based glycopolymers via protein engineering and other methods offers opportunities to control both the number and the spacing of saccharides on a scaffold, as well as the conformation of the polymer backbone, and will therefore facilitate the structure-based design of polymers for inhibition of multivalent binding events. In initial studies, we have synthesized a family of galactose-functionalized glycopolymers with a poly(L-glutamic acid) backbone, in which the density and linker length of the pendant carbohydrate moiety were varied. The composition of the glycopolymers was determined via (1)H NMR spectroscopy, and the impact of saccharide density and linker length, as well as the potential for these polypeptide-based glycopolymers to act as high-affinity inhibitors of the cholera toxin, has been indicated via competitive enzyme-linked immunosorbent assay and fluorescence titration experiments. The results of these studies suggest strategies for optimizing the binding of linear glycopolymers to bacterial toxins and will aid in the design of additional protein-based materials for studying the impact of multivalency, spacing, and backbone rigidity in a variety of biologically relevant binding events.
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19
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Jin Y, Zhang T, Samaranayake YH, Fang HHP, Yip HK, Samaranayake LP. The use of new probes and stains for improved assessment of cell viability and extracellular polymeric substances in Candida albicans biofilms. Mycopathologia 2006; 159:353-60. [PMID: 15883718 DOI: 10.1007/s11046-004-6987-7] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Accepted: 11/30/2004] [Indexed: 11/30/2022]
Abstract
Phenotypic and genotypic cell differentiation is considered an important feature that confers enhanced antifungal resistance in candidal biofilms. Particular emphasis has been placed in this context on the viability of biofilm subpopulations, and their heterogeneity with regard to the production of extracellular polymeric substances (EPS). We therefore assessed the utility of two different labeled lectins Erythrina cristagalli (ECA) and Canavalia ensiformis (ConA), for EPS visualization. To evaluate the viability of candidal biofilms, we further studied combination stains, SYTO9 and propidium iodide (PI). The latter combination has been successfully used to assess bacterial, but not fungal, viability although PI alone has been previously used to stain nuclei in fungal cells. Candida albicans biofilms were developed in a rotating disc biofilm reactor and observed in situ using confocal scanning laser microscopy (CSLM). Our data indicate that SYTO9 and PI are reliable vital stains that may be used to investigate C. albicans biofilms. When used together with ConA, the lectin ECA optimized EPS visualization and revealed differential production of this material in mature candidal biofilms. The foregoing probes and stains and the methodology described should help better characterize C. albicans biofilms in terms of cell their viability, and EPS production.
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Affiliation(s)
- Y Jin
- Division of Oral Biosciences, Faculty Dentistry, The Prince Philip Dental Hospital, University of Hong Kong, 34 Hospital Road, SAR, China
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20
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Ikuta A, Mizuta N, Kitahata S, Murata T, Usui T, Koizumi K, Tanimoto T. Preparation and Characterization of Novel Branched .BETA.-Cyclodextrins Having .BETA.-D-Galactose Residues on the Non-reducing Terminal of the Side Chains and Their Specific Interactions with Peanut (Arachis hypogaea) Agglutinin. Chem Pharm Bull (Tokyo) 2004; 52:51-6. [PMID: 14709868 DOI: 10.1248/cpb.52.51] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Six novel branched beta-cyclodextrins (betaCDs) having beta-D-galactose residues on the non-reducing terminal of the sugar side chains, namely 6(1),6(4)-di-O-(beta-D-galactosyl)-betaCD (10), 6-O-(beta-D-galactosyl)-betaCD (11), 6(1),6(4)-di-O-(beta-lactosyl)-betaCD (14), 6-O-(beta-lactosyl)-betaCD (15), 6(1),6(4)-di-O-(4'-O-beta-D-galactosyl-beta-lactosyl)-betaCD (18), and 6-O-(4'-O-beta-D-galactosyl-beta-lactosyl)-betaCD (19), were chemically synthesized using the trichloroacetimidate method. The reaction products were separated by HPLC on an amino column into dibranched and monobranched betaCDs. Their structures were confirmed by mass spectrometry (MS) and two-dimensional (2D) NMR spectroscopic analysis. To study the length of the sugar side chains attached to the CD ring, which leads to differences in the functions of the branched CDs, interactions of these compounds with peanut (Arachis hypogaea) agglutinin (PNA) were investigated using an optical biosensor and an inhibition assay based on hemagglutination. The results showed that all branched betaCDs interacted with PNA, and the binding affinity was 18>14>10 and 19>15>11 when the derivatives were compared on the basis of side chain length.
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Affiliation(s)
- Akiko Ikuta
- School of Pharmaceutical Sciences, Mukogawa Women's University, 11-68 Koshien Kyuban-cho, Nishinomiya 663-8179, Japan
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Zeng X, Nakaaki Y, Murata T, Usui T. Chemoenzymatic synthesis of glycopolypeptides carrying alpha-Neu5Ac-(2-->3)-beta-D-Gal-(1-->3)-alpha-D-GalNAc, beta-D-Gal-(1-->3)-alpha-D-GalNAc, and related compounds and analysis of their specific interactions with lectins. Arch Biochem Biophys 2000; 383:28-37. [PMID: 11097173 DOI: 10.1006/abbi.2000.2033] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glycopolypeptide (1) carrying the beta-D-Gal-(1-->3)-alpha-D-GalNAc unit as a kind model of asialo-type mucin was synthesized through three steps: enzymatic synthesis of p-nitrophenyl disaccharide glycoside, reduction of the p-nitrophenyl group, and coupling of the amino group with the carboxyl group of poly(L-glutamic acid)s (PGA). In a similar manner, glycopolypeptides (2-7) carrying beta-D-Gal-(1-->3)-beta-D-GalNAc, beta-D-Gal-(1-->3)-beta-D-GlcNAc, beta-D-Gal-(1-->6)-alpha-D-GalNAc, beta-D-Gal-(1-->6)-beta-D-GalNAc, alpha-D-GalNAc, and beta-D-GalNAc, respectively, were synthesized as analogous polymers of polymer 1. Glycopolypeptides 8 and 9 as a mimic of sialo-type mucin were further prepared from polymers 1 and 2 as the acceptor of CMP-Neu5Ac by alpha2,3-(O)-sialyltransferase, respectively. Interactions of these glycopolypeptides with lectins were investigated with the double-diffusion test and the hemagglutination-inhibition assay and in terms of an optical biosensor based on surface plasmon resonance. Polymers 1 and 2 reacted strongly with peanut (Arachis hypogaea) agglutinin (PNA) and Agaricus bisporus agglutinin (ABA). On the other hand, polymers 8 and 9 through sialylation from polymers 1 and 2 reacted with ABA, but did not with PNA. Other polymers 3-7 did not show any reactivity for both the lectins. These results show that PNA acts precisely in an exo manner on the beta-D-Gal-(1-->3)-D-GalNAc sequence, while ABA acts in an endo manner. Polymers 6 and 7 substituted with GalNAc reacted strongly with soybean (Glycine max) agglutinin and Vicia villosa agglutinin B4, regardless of the configuration of the glycosidic linkage. The interaction of all polymers with Bauhinia purpurea agglutinin was much stronger than that of the corresponding sugars. Polymers 8 and 9 reacted with wheat germ (Triticum vulgaris) agglutinin (WGA), to which Neu5Ac residues are needed for binding, but polymers 1 and 2 did not. These sugar-substituted glycopolypeptides interacted specifically with the corresponding lectins. Furthermore, polymers 4-7 reacted with WGA, but the corresponding sugars did not. It suggests that the N-acetyl group along the PGA backbone has a cluster effect for WGA. The artificial glycopolypeptides were shown to be useful as tools and probes of carbohydrate recognition and modeling in the analysis of glycoprotein-lectin interactions.
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Affiliation(s)
- X Zeng
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Japan
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Zeng X, Yoshino R, Murata T, Ajisaka K, Usui T. Regioselective synthesis of p-nitrophenyl glycosides of beta-D-galactopyranosyl-disaccharides by transglycosylation with beta-D-galactosidases. Carbohydr Res 2000; 325:120-31. [PMID: 10795819 DOI: 10.1016/s0008-6215(99)00303-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The beta-D-galactosidase from porcine liver induced regiospecific transglycosylation of beta-D-galactose from beta-D-Gal-OC6H4NO2-o to OH-6 of, respectively, p-nitrophenyl glycoside acceptors of Gal, GlcNAc and GalNAc to afford beta-Gal-(1-->6)-alpha-Gal-OC6H4NO2-p, beta-Gal-(1--> 6)-beta-Gal-OC6H4NO2-p, beta-Gal-(1-->6)-alpha-GalNAc-OC6H4NO2-p, beta-Gal-(1-->6)-beta-GalNAc-OC6H4NO2-p, beta-Gal-(1-->6)-alpha-GlcNAc-OC6H4NO2-p, and beta-Gal-(1-->6)-beta-GlcNAc-OC6H4NO2-p. The enzyme showed much higher transglycosylation activity for the alpha-glycoside acceptors than the corresponding beta-glycoside acceptors. The regioselectivity of the beta-D-galactosidase from Bacillus circulans ATCC 31382 greatly depended on the nature of the acceptor. When alpha-D-GalNAc-OC6H4NO2-p and alpha-D-GlcNAc-OC6H4NO2-p were used as acceptors, the enzyme showed high potency for regioselective synthesis of beta-Gal-(1-->3)-alpha-GalNAc-OC6H4NO2-p and beta-Gal-(1-->3)-alpha-GlcNAc-OC6H4NO2-p in high respective yields of 75.9 and 79.3% based on the acceptors added. However, replacement of beta-D-Gal-OC6H4NO2-p by beta-D-GalNAc-OC6H4NO2-p did change the direction of galactosylation. The enzyme formed regioselectively beta-Gal-(1-->6)-beta-Gal-OC6H4NO2-p with (beta-Gal-1-->(6-beta-Gal-1-->)n6-beta-Gal-OC6H4NO2-p, n = 1-4). No beta-(1-->3)-linked product was detected during the reaction. Use of the two readily available beta-D-galactosidases facilitates the preparation of (1-->3)- and (1-->6)-linked disaccharide glycosides of beta-D-Gal-GalNAc and beta-D-Gal-GlcNAc.
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Affiliation(s)
- X Zeng
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Ohya, Japan
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Murata T, Inukai T, Suzuki M, Yamagishi M, Usui AT. Facile enzymatic conversion of lactose into lacto-N-tetraose and lacto-N-neotetraose. Glycoconj J 1999; 16:189-95. [PMID: 10596893 DOI: 10.1023/a:1007020219275] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Lacto-N-tetraose (Galbeta1 -3GlcNAcbeta1-3Galbeta1-4Glc, LNT) and lacto-N-neotetraose (Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc, LNnT) were enzymatically synthesized by consecutive additions of GlcNAc and Gal residues to lactose. Lacto-N-triose II (GlcNAcbeta1-3Galbeta1-4Glc) was prepared first by the transfer of GlcNAc from UDP-GlcNAc to lactose by beta-1,3-N-acetylglucosaminyltransferase from bovine serum. The resulting lacto-N-triose II was converted into LNT and LNnT utilizing two kinds of beta-D-galactosidase-mediated transglycosylations. Thus, beta-D-galactosidase from Bacillus circulans ATCC31382 induced regioselective galactosyl transfer from o-nitrophenyl beta-D-galactoside to the OH-3" position of lacto-N-triose II, and commercially available beta-D-galactosidase from B. circulans to the OH-4" position of lacto-N-triose II. These convenient processes are suitable for large-scale preparations of LNT and LNnT. As another method, LNT was directly synthesized from lactose as an initial substance, utilizing lacto-N-biosidase (Aureobacterium sp. L-101)-mediated transglycosylation with Galbeta1-3GlcNAcbeta-pNP donor.
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Affiliation(s)
- T Murata
- Department of Applied Biological Chemistry, Shizuoka University, Ohya, Japan
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Zeng X, Murata T, Kawagishi H, Usui T, Kobayashi K. Analysis of specific interactions of synthetic glycopolypeptides carrying N-acetyllactosamine and related compounds with lectins. Carbohydr Res 1998; 312:209-17. [PMID: 9861697 DOI: 10.1016/s0008-6215(98)00259-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Analysis of interactions of synthetic glycopolypeptides with lectins was performed with a biosensor based on surface plasmon resonance (SPR). A series of synthetic oligosaccharide-substituted poly(L-glutamic acid)s were immobilized on sensor surfaces via the gamma-carboxyl groups of their peptide moieties by the surface thiol coupling method. Artificial glycopolypeptides: an N-acetyllactosamine-substituted polymer (1), an N-acetylisolactosamine-substituted polymer (2), a (GlcNAc)3-substituted polymer (3), a (GlcNAc)2-substituted polymer (4), and a p-aminophenyl N-acetyl-beta-lactosaminide-substituted polymer (5), were used as the ligands. On analysis by SPR, surface-bound polymers 1 and 5 reacted with Erythrina cristagalli agglutinin (ECA), Lycopersicon esculentum agglutinin (LEA), Ricinus communis agglutinin-120 (RCA120), and wheat germ (Triticum vulgaris) agglutinin (WGA). Polymer 2 reacted with WGA and RCA120, but did not with ECA and LEA. The results indicate that beta-(1-->4)-linked galactosyl residues are needed for binding to ECA and LEA. Polymer 3 reacted strongly with LEA and WGA, but polymer 4 reacted strongly only with WGA. Affinity constants (KA) for surface-bound polymer 5-lectin interactions were also about 4-61 times as strong as those for surface-bound polymer 1-lectin interactions. These artificial glycopolypeptides were shown to be useful as tools and probes of carbohydrate recognition and modeling in the analysis of glycoprotein-lectin interactions.
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Affiliation(s)
- X Zeng
- Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Japan
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