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Saxena S, Kandasubramanian B. Glycopolymers in molecular recognition, biomimicking and glycotechnology: a review. INT J POLYM MATER PO 2021. [DOI: 10.1080/00914037.2021.1900181] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Shatakshi Saxena
- Centre for Converging Technologies, University of Rajasthan, Jaipur, India
| | - Balasubramanian Kandasubramanian
- Department of Metallurgical and Materials Engineering, Defence Institute of Advanced Technology (DU), Ministry of Defence, Pune, India
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2
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Kwan CS, Cerullo AR, Braunschweig AB. Design and Synthesis of Mucin-Inspired Glycopolymers. Chempluschem 2020; 85:2704-2721. [PMID: 33346954 DOI: 10.1002/cplu.202000637] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/08/2020] [Indexed: 12/11/2022]
Abstract
Mucins are bottlebrush biopolymers that are glycoproteins on the surfaces of cells and as hydrogels secreted inside and outside the body. Mucin function in biology includes cell-cell recognition, signaling, protection, adhesion, and lubrication. Because of their attractive and diverse properties, mucins have recently become the focus of synthetic efforts by researchers who hope to understand and emulate these biomaterials. This review is focused on the development of methodologies for preparing mucin-inspired synthetic oligomers and glycopolymers, including solid-phase synthesis, polymerization of glycosylated monomers, and post-polymerization grafting of glycans to polymer chains. How these synthetic mucins have been used in health applications is discussed. Natural mucins are formed from a conserved set of monomers that are combined into chains of different sequences and lengths to achieve materials with widely diverse properties. Adopting this design paradigm from natural mucins could lead to next-generation bioinspired synthetic materials.
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Affiliation(s)
- Chak-Shing Kwan
- The Advanced Science Research Center at the, Graduate Center of the City University of New York, 85 St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Chemistry and Biochemistry, Hunter College, 695 Park Ave, New York, NY, 10065, USA
| | - Antonio R Cerullo
- The Advanced Science Research Center at the, Graduate Center of the City University of New York, 85 St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Chemistry and Biochemistry, Hunter College, 695 Park Ave, New York, NY, 10065, USA.,The PhD program in Biochemistry, Graduate Center of the City University of New York, 365 5th Ave, New York, NY, 10016, USA
| | - Adam B Braunschweig
- The Advanced Science Research Center at the, Graduate Center of the City University of New York, 85 St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Chemistry and Biochemistry, Hunter College, 695 Park Ave, New York, NY, 10065, USA.,The PhD program in Biochemistry, Graduate Center of the City University of New York, 365 5th Ave, New York, NY, 10016, USA.,The PhD program in Chemistry, Graduate Center of the City University of New York, 365 5th Ave, New York, NY, 10016, USA
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3
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Thomas B, Yan KC, Hu XL, Donnier-Maréchal M, Chen GR, He XP, Vidal S. Fluorescent glycoconjugates and their applications. Chem Soc Rev 2020; 49:593-641. [DOI: 10.1039/c8cs00118a] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fluorescent glycoconjugates are discussed for their applications in biology in vitro, in cell assays and in animal models. Advantages and limitations are presented for each design using a fluorescent core conjugated with glycosides, or vice versa.
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Affiliation(s)
- Baptiste Thomas
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires
- Laboratoire de Chimie Organique 2-Glycochimie
- UMR 5246
- CNRS and Université Claude Bernard Lyon 1
- Université de Lyon
| | - Kai-Cheng Yan
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering
- Feringa Nobel Prize Scientist Joint Research Center
- School of Chemistry and Molecular Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Xi-Le Hu
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering
- Feringa Nobel Prize Scientist Joint Research Center
- School of Chemistry and Molecular Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Marion Donnier-Maréchal
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires
- Laboratoire de Chimie Organique 2-Glycochimie
- UMR 5246
- CNRS and Université Claude Bernard Lyon 1
- Université de Lyon
| | - Guo-Rong Chen
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering
- Feringa Nobel Prize Scientist Joint Research Center
- School of Chemistry and Molecular Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Xiao-Peng He
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering
- Feringa Nobel Prize Scientist Joint Research Center
- School of Chemistry and Molecular Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Sébastien Vidal
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires
- Laboratoire de Chimie Organique 2-Glycochimie
- UMR 5246
- CNRS and Université Claude Bernard Lyon 1
- Université de Lyon
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4
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Lee J, Kim JC, Lee H, Song S, Kim H, Ree M. Self-Assembling Brush Polymers Bearing Multisaccharides. Macromol Rapid Commun 2017; 38. [DOI: 10.1002/marc.201700013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 02/11/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Jongchan Lee
- Department of Chemistry; Division of Advanced Materials Science; Pohang Accelerator Laboratory, and Polymer Research Institute; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
| | - Jin Chul Kim
- Department of Chemistry; Division of Advanced Materials Science; Pohang Accelerator Laboratory, and Polymer Research Institute; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
- Research Centre for Green Fine Chemicals; Chemical Convergence Research Division; Korea Research Institute of Chemical Technology; Ulsan 44412 Republic of Korea
| | - Hoyeol Lee
- Department of Chemistry; Division of Advanced Materials Science; Pohang Accelerator Laboratory, and Polymer Research Institute; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
| | - Sungjin Song
- Department of Chemistry; Division of Advanced Materials Science; Pohang Accelerator Laboratory, and Polymer Research Institute; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
| | - Heesoo Kim
- Department of Microbiology and Dongguk Medical Institute; Dongguk University College of Medicine; Gyeongju 38066 Republic of Korea
| | - Moonhor Ree
- Department of Chemistry; Division of Advanced Materials Science; Pohang Accelerator Laboratory, and Polymer Research Institute; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
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5
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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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Belardi B, Bertozzi CR. Chemical Lectinology: Tools for Probing the Ligands and Dynamics of Mammalian Lectins In Vivo. ACTA ACUST UNITED AC 2015; 22:983-93. [PMID: 26256477 DOI: 10.1016/j.chembiol.2015.07.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/29/2015] [Accepted: 07/08/2015] [Indexed: 02/06/2023]
Abstract
The importance and complexity associated with the totality of glycan structures, i.e. the glycome, has garnered significant attention from chemists and biologists alike. However, what is lacking from this biochemical picture is how cells, tissues, and organisms interpret glycan patterns and translate this information into appropriate responses. Lectins, glycan-binding proteins, are thought to bridge this gap by decoding the glycome and dictating cell fate based on the underlying chemical identities and properties of the glycome. Yet, our understanding of the in vivo ligands and function for most lectins is still incomplete. This review focuses on recent advances in chemical tools to study the specificity and dynamics of mammalian lectins in live cells. A picture emerges of lectin function that is highly sensitive to its organization, which in turn drastically shapes immunity and cancer progression. We hope this review will inspire biologists to make use of these new techniques and stimulate chemists to continue developing innovative approaches to probe lectin biology in vivo.
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Affiliation(s)
- Brian Belardi
- Departments of Chemistry and Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Carolyn R Bertozzi
- Department of Chemistry and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305-4401, USA.
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L-selectin shedding is activated specifically within transmigrating pseudopods of monocytes to regulate cell polarity in vitro. Proc Natl Acad Sci U S A 2015; 112:E1461-70. [PMID: 25775539 DOI: 10.1073/pnas.1417100112] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
L-selectin is a cell adhesion molecule that tethers free-flowing leukocytes from the blood to luminal vessel walls, facilitating the initial stages of their emigration from the circulation toward an extravascular inflammatory insult. Following shear-resistant adhesion to the vessel wall, L-selectin has frequently been reported to be rapidly cleaved from the plasma membrane (known as ectodomain shedding), with little knowledge of the timing or functional consequence of this event. Using advanced imaging techniques, we observe L-selectin shedding occurring exclusively as primary human monocytes actively engage in transendothelial migration (TEM). Moreover, the shedding was localized to transmigrating pseudopods within the subendothelial space. By capturing monocytes in midtransmigration, we could monitor the subcellular distribution of L-selectin and better understand how ectodomain shedding might contribute to TEM. Mechanistically, L-selectin loses association with calmodulin (CaM; a negative regulator of shedding) specifically within transmigrating pseudopods. In contrast, L-selectin/CaM interaction remained intact in nontransmigrated regions of monocytes. We show phosphorylation of L-selectin at Ser 364 is critical for CaM dissociation, which is also restricted to the transmigrating pseudopod. Pharmacological or genetic inhibition of L-selectin shedding significantly increased pseudopodial extensions in transmigrating monocytes, which potentiated invasive behavior during TEM and prevented the establishment of front/back polarity for directional migration persistence once TEM was complete. We conclude that L-selectin shedding directly regulates polarity in transmigrated monocytes, which affirms an active role for this molecule in driving later stages of the multistep adhesion cascade.
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8
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Sunasee R, Adokoh CK, Darkwa J, Narain R. Therapeutic potential of carbohydrate-based polymeric and nanoparticle systems. Expert Opin Drug Deliv 2014; 11:867-84. [DOI: 10.1517/17425247.2014.902048] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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10
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Abstract
Glycans are key participants in biological processes ranging from reproduction to cellular communication to infection. Revealing glycan roles and the underlying molecular mechanisms by which glycans manifest their function requires access to glycan derivatives that vary systematically. To this end, glycopolymers (polymers bearing pendant carbohydrates) have emerged as valuable glycan analogs. Because glycopolymers can readily be synthesized, their overall shape can be varied, and they can be altered systematically to dissect the structural features that underpin their activities. This review provides examples in which glycopolymers have been used to effect carbohydrate-mediated signal transduction. Our objective is to illustrate how these powerful tools can reveal the molecular mechanisms that underlie carbohydrate-mediated signal transduction.
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Affiliation(s)
- Laura L Kiessling
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI 53706, USA.
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11
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Synthesis of Glycopolymer Architectures by Reversible-Deactivation Radical Polymerization. Polymers (Basel) 2013. [DOI: 10.3390/polym5020431] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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12
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Sulfoform generation from an orthogonally protected disaccharide. Carbohydr Res 2012; 355:19-27. [PMID: 22624867 DOI: 10.1016/j.carres.2012.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 04/12/2012] [Accepted: 04/14/2012] [Indexed: 11/23/2022]
Abstract
An orthogonally protected disaccharide (GlcN(α1→4)Glc) with a β-linked 2'-aminoethyl linker was used to generate a series of sulfated derivatives (sulfoforms), with a 6-O-sulfate on the glucose residue and one or more sulfate esters on the terminal glucosamine. Deprotection and sulfonation steps were performed in solution and in variable order, with isolated yields of 36-54% (85-90% per operation) after HPLC purification. The modular deprotection-sulfonation sequences can be performed with efficient recovery of the polysulfate products, and avoids complications associated with heterogeneous reactivity in solid-phase synthesis.
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Peterson-Kaufman KJ, Carlson CD, Rodríguez-Martínez JA, Ansari AZ. Nucleating the assembly of macromolecular complexes. Chembiochem 2010; 11:1955-62. [PMID: 20812316 PMCID: PMC4176617 DOI: 10.1002/cbic.201000255] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Indexed: 12/23/2022]
Abstract
Nature constructs intricate complexes containing numerous binding partners in order to direct a variety of cellular processes. Researchers have taken a cue from these events to develop synthetic molecules that can nucleate natural and unnatural interactions for a diverse set of applications. These molecules can be designed to drive protein dimerization or to modulate the interactions between proteins, lipids, DNA, or RNA and thereby alter cellular pathways. A variety of components within the cellular machinery can be recruited with or replaced by synthetic compounds. Directing the formation of multicomponent complexes with new synthetic molecules can allow unprecedented control over the cellular machinery.
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Affiliation(s)
| | - Clayton D. Carlson
- Department of Biochemistry and the Genome Center, University of Wisconsin, 433 Babcock Drive. Madison, WI 53706
| | - José A. Rodríguez-Martínez
- Department of Biochemistry and the Genome Center, University of Wisconsin, 433 Babcock Drive. Madison, WI 53706
| | - Aseem Z. Ansari
- Department of Biochemistry and the Genome Center, University of Wisconsin, 433 Babcock Drive. Madison, WI 53706
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15
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Ring-opening metathesis polymerization of steroid-conjugated norbornenes and gradual release of estrone from a polymer film. REACT FUNCT POLYM 2010. [DOI: 10.1016/j.reactfunctpolym.2010.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Alidedeoglu AH, York AW, Rosado DA, McCormick CL, Morgan SE. Bioconjugation of D-glucuronic acid sodium salt to well-defined primary amine-containing homopolymers and block copolymers. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pola.24083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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17
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Maheshwari R, Levenson EA, Kiick KL. Manipulation of electrostatic and saccharide linker interactions in the design of efficient glycopolypeptide-based cholera toxin inhibitors. Macromol Biosci 2010; 10:68-81. [PMID: 19780061 PMCID: PMC2893567 DOI: 10.1002/mabi.200900182] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Multivalent, glycopolymer inhibitors designed for the treatment of disease and pathogen infection have shown improvements in binding correlated with general changes in glycopolymer architecture and composition. We have previously demonstrated that control of glycopolypeptide backbone extension and ligand spacing significantly impacts the inhibition of the cholera toxin B subunit pentamer (CT B(5)) by these polymers. In the studies reported here, we elucidate the role of backbone charge and linker length in modulating the inhibition event. Peptides of the sequence AXPXG (where X is a positive, neutral or negative amino acid), equipped with the alkyne functionality of propargyl glycine, were designed and synthesized via solid-phase peptide synthetic methods and glycosylated via Cu(I)-catalyzed alkyne-azide cycloaddition reactions. The capacity of the glycopeptides to inhibit the binding of the B(5) subunit of cholera toxin was evaluated. These studies indicated that glycopeptides with a negatively charged backbone show improved inhibition of the binding event relative to the other glycopeptides. In addition, variations in the length of the linker between the peptide and the saccharide ligand also affected the inhibition of CT by the glycopeptides. Our findings suggest that, apart from appropriate saccharide spacing and polypeptide chain extension, saccharide linker conformation and the systematic placement of charges on the polypeptide backbone are also significant variables that can be tuned to improve the inhibitory potencies of glycopolypeptide-based multivalent inhibitors.
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Affiliation(s)
- Ronak Maheshwari
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, Delaware 19716 USA Fax: +1 (302) 831-4545
| | - Eric A. Levenson
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716 USA
| | - Kristi L. Kiick
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, Delaware 19716 USA Fax: +1 (302) 831-4545. Delaware Biotechnology Institute, 15 Innovation Way, Newark, Delaware 19711 USA
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Cerrada ML, Sánchez-Chaves M, Ruiz C, Fernández-García M. Recognition Abilities and Development of Heat-Induced Entangled Networks in Lactone-Derived Glycopolymers Obtained from Ethylene-vinyl Alcohol Copolymers. Biomacromolecules 2009; 10:1828-37. [DOI: 10.1021/bm900255q] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- M. L. Cerrada
- Instituto de Ciencia y Tecnología de Polímeros (CSIC), C/ Juan de la Cierva 3, 28006 Madrid, Spain
| | - M. Sánchez-Chaves
- Instituto de Ciencia y Tecnología de Polímeros (CSIC), C/ Juan de la Cierva 3, 28006 Madrid, Spain
| | - C. Ruiz
- Instituto de Ciencia y Tecnología de Polímeros (CSIC), C/ Juan de la Cierva 3, 28006 Madrid, Spain
| | - M. Fernández-García
- Instituto de Ciencia y Tecnología de Polímeros (CSIC), C/ Juan de la Cierva 3, 28006 Madrid, Spain
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Deng Z, Ahmed M, Narain R. Novel well-defined glycopolymers synthesized via the reversible addition fragmentation chain transfer process in aqueous media. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pola.23187] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Cairo CW, Golan DE. T cell adhesion mechanisms revealed by receptor lateral mobility. Biopolymers 2008; 89:409-19. [PMID: 18041065 DOI: 10.1002/bip.20898] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cell surface receptors mediate the exchange of information between cells and their environment. In the case of adhesion receptors, the spatial distribution and molecular associations of the receptors are critical to their function. Therefore, understanding the mechanisms regulating the distribution and binding associations of these molecules is necessary to understand their functional regulation. Experiments characterizing the lateral mobility of adhesion receptors have revealed a set of common mechanisms that control receptor function and thus cellular behavior. The T cell provides one of the most dynamic examples of cellular adhesion. An individual T cell makes innumerable intercellular contacts with antigen presenting cells, the vascular endothelium, and many other cell types. We review here the mechanisms that regulate T cell adhesion receptor lateral mobility as a window into the molecular regulation of these systems, and we present a general framework for understanding the principles and mechanisms that are likely to be common among these and other cellular adhesion systems. We suggest that receptor lateral mobility is regulated via four major mechanisms-reorganization, recruitment, dispersion, and anchoring-and we review specific examples of T cell adhesion receptor systems that utilize one or more of these mechanisms.
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Affiliation(s)
- Christopher W Cairo
- Department of Chemistry, Alberta Ingenuity Centre for Carbohydrate Science, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
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Affiliation(s)
- Si Kyung Yang
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, and Department of Chemistry and Molecular Design Institute, New York University, New York, New York 10003
| | - Marcus Weck
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, and Department of Chemistry and Molecular Design Institute, New York University, New York, New York 10003
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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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Spain SG, Gibson MI, Cameron NR. Recent advances in the synthesis of well-defined glycopolymers. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/pola.22106] [Citation(s) in RCA: 215] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Coullerez G, Seeberger PH, Textor M. Merging Organic and Polymer Chemistries to Create Glycomaterials for Glycomics Applications. Macromol Biosci 2006; 6:634-47. [PMID: 16881090 DOI: 10.1002/mabi.200600090] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
[Image: see text] Oligosaccharides at cell surfaces are known to play a critical role in many biological processes such as biorecognition, interactions between cells and with artificial surfaces, immune response, infection and inflammation. In order to facilitate studies of the role of sugars, an increasing number of novel tools are becoming available. New synthetic strategies now provide much more efficient access to complex carbohydrates or glycoconjugates. Branched carbohydrates and hybrids of carbohydrates conjugated to polymers have been prepared using solution and/or solid-phase synthesis and advanced methods of polymerization. These materials are essential for the development of methodologies to study and map the molecular structure-function relationship at interfaces. This article highlights recent advances in the synthesis of carbohydrates and polymer hybrids mimicking the properties and functionalities of the natural oligosaccharides, as well as selected applications in biology, biotechnology and diagnostics.
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Affiliation(s)
- Géraldine Coullerez
- Laboratory for Surface Science and Technology, BioInterfaceGroup, Department of Materials, ETH Zurich, Switzerland.
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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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Kiessling LL, Gestwicki JE, Strong LE. Synthetische multivalente Liganden als Sonden für die Signaltransduktion. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200502794] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kiessling LL, Gestwicki JE, Strong LE. Synthetic multivalent ligands as probes of signal transduction. Angew Chem Int Ed Engl 2006; 45:2348-68. [PMID: 16557636 PMCID: PMC2842921 DOI: 10.1002/anie.200502794] [Citation(s) in RCA: 687] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cell-surface receptors acquire information from the extracellular environment and coordinate intracellular responses. Many receptors do not operate as individual entities, but rather as part of dimeric or oligomeric complexes. Coupling the functions of multiple receptors may endow signaling pathways with the sensitivity and malleability required to govern cellular responses. Moreover, multireceptor signaling complexes may provide a means of spatially segregating otherwise degenerate signaling cascades. Understanding the mechanisms, extent, and consequences of receptor co-localization and interreceptor communication is critical; chemical synthesis can provide compounds to address the role of receptor assembly in signal transduction. Multivalent ligands can be generated that possess a variety of sizes, shapes, valencies, orientations, and densities of binding elements. This Review focuses on the use of synthetic multivalent ligands to characterize receptor function.
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Affiliation(s)
- Laura L Kiessling
- Department of Chemistry, University of Wisconsin--Madison, 1101 University Ave., Madison, WI 53706, USA.
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Ushakova NA, Preobrazhenskaya ME, Bird MI, Priest R, Semenov AV, Mazurov AV, Nifantiev NE, Pochechueva TV, Galanina OE, Bovin NV. Monomeric and Multimeric Blockers of Selectins: Comparison of in vitro and in vivo Activity. BIOCHEMISTRY (MOSCOW) 2005; 70:432-9. [PMID: 15892609 DOI: 10.1007/s10541-005-0133-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The potency of the oligosaccharides SiaLe(x), SiaLe(a), HSO(3)Le(x), and HSO(3)Le(a), their conjugates with polyacrylamide (PAA, 40 kD), and other monomeric and polymeric selectin inhibitors has been compared with that of the polysaccharide fucoidan. The following assay systems were used: 1) a 96-well assay based either on the use of recombinant E-, P-, and L-selectins or an analogous assay with natural P-selectin isolated from human platelets; 2) a platelet-based P-selectin cell assay; and 3) a rat model of peritoneal inflammation. IC(50) values for the neoglycoconjugate SiaLe(a)-PAA were 6, 40, and 85 microM for recombinant E-, P-, and L-selectins, respectively; all monomeric inhibitors were about two orders of magnitude weaker. PAA-conjugates, containing as a ligand tyrosine-O-sulfate (sTyr) in addition to one of the sialylated oligosaccharides, were the most potent synthetic blockers in vitro. Compared with fucoidan, the most potent known P- and L-selectin blocker, the bi-ligand glycoconjugate HSO(3)Le(a)-PAA-sTyr displayed similar inhibitory activity in vitro towards L-selectin and about ten times lower activity towards P-selectin. All of the tested synthetic polymers displayed a similar ability to inhibit neutrophil extravasation in the peritonitis model (in vivo) at 10 mg/kg. The data provide evidence that monomeric SiaLe(x) is considerably more effective as a selectin blocker in vivo than in vitro, whereas the opposite is true for fucoidan and the bi-ligand neoglycoconjugate HSO(3)Le(a)-PAA-sTyr.
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Affiliation(s)
- N A Ushakova
- Orekhovich Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, 119121 Moscow, Russia.
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Mowery P, Yang ZQ, Gordon EJ, Dwir O, Spencer AG, Alon R, Kiessling LL. Synthetic glycoprotein mimics inhibit L-selectin-mediated rolling and promote L-selectin shedding. ACTA ACUST UNITED AC 2005; 11:725-32. [PMID: 15157883 DOI: 10.1016/j.chembiol.2004.03.027] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2003] [Revised: 03/05/2004] [Accepted: 03/11/2004] [Indexed: 12/18/2022]
Abstract
L-selectin is a leukocyte cell-surface protein that facilitates the rolling of leukocytes along the endothelium, a process that leads to leukocyte migration to a site of infection. Preventing L-selectin-mediated rolling minimizes leukocyte adhesion and extravasation; therefore, compounds that inhibit rolling may act as anti-inflammatory agents. To investigate the potential role of multivalent ligands as rolling inhibitors, compounds termed neoglycopolymers were synthesized that possess key structural features of physiological L-selectin ligands. Sulfated neoglycopolymers substituted with sialyl Lewis x derivatives (3',6-disulfo Lewis x or 6-sulfo sialyl Lewis x) or a sulfatide analog (3,6-disulfo galactose) inhibited L-selectin-mediated rolling of lymphoid cells. Functional analysis of the inhibitory ligands indicates that they also induce proteolytic release of L-selectin. Thus, their inhibitory potency may arise from their ability to induce shedding. Our data indicate that screening for compounds that promote L-selectin release can identify ligands that inhibit rolling.
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Affiliation(s)
- Patricia Mowery
- Department of Biochemistry, 433 Babcock Drive, University of Wisconsin-Madison, Madison, WI 53706 USA
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Albertin L, Stenzel M, Barner-Kowollik C, Foster LJR, Davis TP. Well-Defined Glycopolymers from RAFT Polymerization: Poly(methyl 6-O-methacryloyl-α-d-glucoside) and Its Block Copolymer with 2-Hydroxyethyl Methacrylate. Macromolecules 2004. [DOI: 10.1021/ma049129+] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Shinohara KI, Narita A, Oyoshi T, Bando T, Teraoka H, Sugiyama H. Sequence-Specific Gene Silencing in Mammalian Cells by Alkylating Pyrrole−Imidazole Polyamides. J Am Chem Soc 2004; 126:5113-8. [PMID: 15099094 DOI: 10.1021/ja031673v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Gene silencing was examined by sequence-specific alkylation of DNA by N-methylpyrrole (Py)-N-methylimidazole (Im) hairpin polyamides. Polyamides ImImPyPygammaImImPyLDu86 (A) and ImImPyPygammaImPyPyLDu86 (B) selectively alkylated the coding regions of the renilla and firefly luciferases, respectively, according to the base pair recognition rule of Py-Im polyamides. Two different plasmids, encoding renilla luciferase and firefly luciferase, were used as vectors to examine the effect of alkylation on gene silencing. Transfection of the alkylated luciferase vectors-by polyamide A or B-into HeLa, 293, and NIH3T3 cells demonstrated that these sequence-specific DNA alkylations lead to selective silencing of gene expression. Next, the vectors were cotransfected into HeLa cells and the cells were treated with polyamide A or B. Selective reduction of luciferase activities was caused by both polyamides. On the basis of this sequence-specific alkylation and gene silencing activity, these alkylating Py-Im polyamides thus have potential as antitumor drugs to target specific gene expression in human cells.
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Affiliation(s)
- Ken-Ichi Shinohara
- Department of Pathological Biochemistry, Medical Research Institute, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo 101-0062, Japan
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Albertin L, Kohlert C, Stenzel M, Foster LJR, Davis TP. Chemoenzymatic Synthesis of Narrow-Polydispersity Glycopolymers: Poly(6-O-vinyladipoyl-d-glucopyranose). Biomacromolecules 2004; 5:255-60. [PMID: 15002981 DOI: 10.1021/bm034199u] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The glycomonomer 6-O-vinyladipoyl-D-glucopyranose was prepared via lipase catalyzed transesterification of divinyladipate with alpha-D-glucopyranose in dry acetonitrile and acetone. The desired 6-O regioisomer was obtained in good yield, and its structure was confirmed by correlation NMR spectroscopy. Controlled radical polymerization of the unprotected monomer was performed in protic media using both xanthate and dithiocarbamate as chain transfer agents to give poly(6-O-vinyladipoyl-D-glucopyranose) with Mn of 17 and 19 kDa (SEC) respectively and a polydispersity as low as 1.10. To the best of our knowledge, this is the first example of a narrow-polydispersity, poly(vinyl ester)-like glycopolymer.
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Affiliation(s)
- Luca Albertin
- Centre for Advanced Macromolecular Design, School of Chemical Engineering and Industrial Chemistry, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
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Oyoshi T, Kawakami W, Narita A, Bando T, Sugiyama H. Inhibition of transcription at a coding sequence by alkylating polyamide. J Am Chem Soc 2003; 125:4752-4. [PMID: 12696893 DOI: 10.1021/ja029196o] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transcription from DNA sequence-specifically alkylated by a hairpin polyamide (ImPyPy-gamma-ImPyLDu86, 1) was investigated. High-resolution polyacrylamide gel electrophoresis demonstrated that conjugate 1 alkylated a 993-bp DNA fragment, in accordance with the Py-Im recognition rule, predominantly at the one match site on the GFP-encoding strand and at four sites (I'-IV') on the noncoding strand. Alkylation of DNA inhibited the formation of full-length mRNA and caused the transcription of truncated mRNA. Polyacrylamide gel electrophoresis demonstrated that the length of the truncated mRNA was consistent with the alkylated site on the coding strand. Complete inhibition of full-length mRNA synthesis was observed in the presence of 50 nM 1. In clear contrast, the hydrolyzed derivative of 1, designated 2, produced no truncated mRNA, nor did it significantly retard transcription: >80% transcription of full-length mRNA was observed at 50 nM. These results clearly indicate that inhibition of transcription can be achieved with alkylating Py-Im polyamide even in the coding regions of genes.
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Affiliation(s)
- Takanori Oyoshi
- Division of Biofunctional Molecules, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental Univ., Chiyoda, Tokyo 101-0062, Japan
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Owen RM, Gestwicki JE, Young T, Kiessling LL. Synthesis and applications of end-labeled neoglycopolymers. Org Lett 2002; 4:2293-6. [PMID: 12098230 DOI: 10.1021/ol0259239] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Neoglycopolymers that vary in length and contain a single fluorescent reporter group were synthesized using ring-opening metathesis polymerization (ROMP). The utility of these materials is demonstrated by the development of a cellular binding assay for L-selectin, a cell surface protein that plays a role in inflammation. The data reveal that these multivalent ligands interact with multiple copies of L-selectin.
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Affiliation(s)
- Robert M Owen
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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Gestwicki JE, Cairo CW, Mann DA, Owen RM, Kiessling LL. Selective immobilization of multivalent ligands for surface plasmon resonance and fluorescence microscopy. Anal Biochem 2002; 305:149-55. [PMID: 12054443 DOI: 10.1006/abio.2002.5652] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cell surface multivalent ligands, such as proteoglycans and mucins, are often tethered by a single attachment point. In vitro, however, it is difficult to immobilize multivalent ligands at single sites due to their heterogeneity. Moreover, multivalent ligands often lack a single group with reactivity orthogonal to other functionality in the ligand. Biophysical analyses of multivalent ligand-receptor interactions would benefit from the availability of strategies for uniform immobilization of multivalent ligands. To this end, we report the design and synthesis of a multivalent ligand that has a single terminal orthogonal functional group and we demonstrate that this material can be selectively immobilized onto a surface suitable for surface plasmon resonance (SPR) experiments. The polymeric ligand we generated displays multiple copies of 3,6-disulfogalactose, and it can bind to the cell adhesion molecules P- and L-selectin. Using SPR measurements, we found that surfaces displaying our multivalent ligands bind specifically to P- and L-selectin. The affinities of P- and L-selectin for surfaces displaying the multivalent ligand are five- to sixfold better than the affinities for a surface modified with the corresponding monovalent ligand. In addition to binding soluble proteins, surfaces bearing immobilized polymers bound to cells displaying L-selectin. Cell binding was confirmed by visualizing adherent cells by fluorescence microscopy. Together, our results indicate that synthetic surfaces can be created by selective immobilization of multivalent ligands and that these surfaces are capable of binding soluble and cell-surface-associated receptors with high affinity.
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Affiliation(s)
- Jason E Gestwicki
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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Abstract
Biochemistry in the context of a living cell or organism is complicated by many variables such as supramolecular organization, cytoplasmic viscosity, and substrate heterogeneity. While these variables are easily excluded or avoided in reconstituted systems, they must be dealt with in cellular environments. New developments have allowed researchers to begin probing the inner workings of the cell to gain new insight into cell function and metabolism. Advances in cellular imaging and in small molecule-controlled gene expression, signal transduction and cell surface modification are discussed in this review. These techniques have permitted the study of molecular components within the context of living cells.
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Affiliation(s)
- Brian N Cook
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
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Artificial Multivalent Sugar Ligands to Understand and Manipulate Carbohydrate-Protein Interactions. HOST-GUEST CHEMISTRY 2002. [DOI: 10.1007/3-540-45010-6_7] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Houseman BT, Mrksich M. Model Systems for Studying Polyvalent Carbohydrate Binding Interactions. ACTA ACUST UNITED AC 2001. [DOI: 10.1007/3-540-45010-6_1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
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Abstract
Chemical tools have proven indispensable for studies in glycobiology. Synthetic oligosaccharides and glycoconjugates provide materials for correlating structure with function. Synthetic mimics of the complex assemblies found on cell surfaces can modulate cellular interactions and are under development as therapeutic agents. Small molecule inhibitors of carbohydrate biosynthetic and processing enzymes can block the assembly of specific oligosaccharide structures. Inhibitors of carbohydrate recognition and biosynthesis can reveal the biological functions of the carbohydrate epitope and its cognate receptors. Carbohydrate biosynthetic pathways are often amenable to interception with synthetic unnatural substrates. Such metabolic interference can block the expression of oligosaccharides or alter the structures of the sugars presented on cells. Collectively, these chemical approaches are contributing great insight into the myriad biological functions of oligosaccharides.
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Affiliation(s)
- C R Bertozzi
- Departments of Chemistry and Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
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Kiessling LL, Gestwicki JE, Strong LE. Synthetic multivalent ligands in the exploration of cell-surface interactions. Curr Opin Chem Biol 2000; 4:696-703. [PMID: 11102876 DOI: 10.1016/s1367-5931(00)00153-8] [Citation(s) in RCA: 426] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Processes such as cell-cell recognition and the initiation of signal transduction often depend on the formation of multiple receptor-ligand complexes at the cell surface. Synthetic multivalent ligands are unique probes of these complex cell-surface-binding events. Multivalent ligands can be used as inhibitors of receptor-ligand interactions or as activators of signal transduction pathways. Emerging from these complementary applications is insight into how cells exploit multivalent interactions to bind with increased avidity and specificity and how cell-surface receptor organization influences signaling and the cellular responses that result.
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Affiliation(s)
- L L Kiessling
- Departments of Chemistry and Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Gordon EJ, Gestwicki JE, Strong LE, Kiessling LL. Synthesis of end-labeled multivalent ligands for exploring cell-surface-receptor-ligand interactions. CHEMISTRY & BIOLOGY 2000; 7:9-16. [PMID: 10662681 DOI: 10.1016/s1074-5521(00)00060-0] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Ring-opening metathesis polymerization (ROMP) is a powerful synthetic method for generating unique materials. The functional group tolerance of ruthenium ROMP initiators allows the synthesis of a wide range of biologically active polymers. We generated multivalent ligands that inhibit cell surface L-selectin, a protein that mediates lymphocyte homing and leukocyte recruitment in inflammation. We hypothesized that these ligands function through specific, multivalent binding to L-selection. To examine this and to develop a general method for synthesizing multivalent materials with end-labels, we investigated functionalized enol ethers as capping agents in ruthenium-initiated ROMP. RESULTS We synthesized a bifunctional molecule that introduces a unique end group by terminating ruthenium-initiated ROMP reactions. This agent contains an enol ether at one end and a masked carboxylic acid at the other. We conjugated a fluorescein derivative to an end-capped neoglycopolymer that had previously been shown to inhibit L-selection function. We used fluorescence microscopy to visualize neoglycopolymer binding to cells displaying L-selectin. Our results suggest that the neoglycopolymers bind specifically to cell surface L-selectin through multivalent interactions. CONCLUSIONS Ruthenium-initiated ROMP can be used to generate biologically active, multivalent ligands terminated with a latent functional group. The functionalized polymers can be labeled with a variety of molecular tags, including fluorescent molecules, biotin, lipids or antibodies. The ability to conjugate reporter groups to ROMP polymers using this strategy has broad applications in the material and biological sciences.
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Affiliation(s)
- E J Gordon
- Departments of Chemistry and Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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Sanders WJ, Gordon EJ, Dwir O, Beck PJ, Alon R, Kiessling LL. Inhibition of L-selectin-mediated leukocyte rolling by synthetic glycoprotein mimics. J Biol Chem 1999; 274:5271-8. [PMID: 10026133 DOI: 10.1074/jbc.274.9.5271] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Synthetic carbohydrate and glycoprotein mimics displaying sulfated saccharide residues have been assayed for their L-selectin inhibitory properties under static and flow conditions. Polymers displaying the L-selectin recognition epitopes 3',6-disulfo Lewis x(Glc) (3-O-SO3-Galbeta1alpha4(Fucalpha1alpha3)-6-O-SO3-Glcbeta+ ++-OR) and 3',6'-disulfo Lewis x(Glc) (3, 6-di-O-SO3-Galbeta1alpha4(Fucalpha1alpha3)Glcbeta-OR) both inhibit L-selectin binding to heparin under static, cell-free binding conditions with similar efficacies. Under conditions of shear flow, however, only the polymer displaying 3',6-disulfo Lewis x(Glc) inhibits the rolling of L-selectin-transfected cells on the glycoprotein ligand GlyCAM-1. Although it has been shown to more effective than sialyl Lewis x at blocking the L-selectin-GlyCAM-1 interaction in static binding studies, the corresponding monomer had no effect in the dynamic assay. These data indicate that multivalent ligands are far more effective inhibitors of L-selectin-mediated rolling than their monovalent counterparts and that the inhibitory activities are dependent on the specific sulfation pattern of the recognition epitope. Importantly, our results indicate the L-selectin specificity for one ligand over another found in static, cell-free binding assays is not necessarily retained under the conditions of shear flow. The results suggest that monovalent or polyvalent carbohydrate or glycoprotein mimetics that inhibit selectin binding in static assays may not block the more physiologically relevant process of selectin-mediated rolling.
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Affiliation(s)
- W J Sanders
- Departments of Chemistry and Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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