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Wang K, Wang W, Zhang R, Liu Y, Hou C, Guo Y, Zhang C. Preparation of low molecular weight chondroitin sulfate from different sources by H 2O 2/ascorbic acid degradation and its degradation mechanism. Food Chem 2024; 434:137392. [PMID: 37725843 DOI: 10.1016/j.foodchem.2023.137392] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/21/2023]
Abstract
Low molecular weight chondroitin sulfate (LMCS) has attention for enhanced bioavailability and bioactivity compared to native CS. We optimized H2O2/ ascorbic acid (Vc) degradation conditions to prepare LMCS from chicken, bovine, and shark cartilages. Degradation kinetics models and chemical composition data of LMCS showed the GlcA residues of chondroitin-4-sulfate (CSA) may be preferentially attacked. Nuclear magnetic resonance (NMR) spectroscopy and high-performance liquid chromatography-electrospray mass spectrometry (HPLC-MS) indicated that the CH of GlcA in CS was broken through a hydrogen abstraction reaction to break the β-(1 → 3) bond and form the hexendioic acid product. Standard density functional theory (DFT) calculations indicated that the energy required for the hydrogen abstraction from the C1-H bond in GlcA was lower than that of GalNAc. Molecular dynamics (MD) showed that CSA was more likely to interact with hydroxyl radicals (·OH) than non-sulfated chondroitin (CSO) and chondroitin-6-sulfate (CSC). These results provide guidance for producing LMCS.
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Affiliation(s)
- Kangyu Wang
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wenfang Wang
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Ruishu Zhang
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yue Liu
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Chengli Hou
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yujie Guo
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Chunhui Zhang
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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Wang K, Qi L, Zhao L, Liu J, Guo Y, Zhang C. Degradation of chondroitin sulfate: Mechanism of degradation, influence factors, structure-bioactivity relationship and application. Carbohydr Polym 2022; 301:120361. [DOI: 10.1016/j.carbpol.2022.120361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/12/2022] [Accepted: 11/13/2022] [Indexed: 11/19/2022]
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In-Depth Molecular Dynamics Study of All Possible Chondroitin Sulfate Disaccharides Reveals Key Insight into Structural Heterogeneity and Dynamism. Biomolecules 2022; 12:biom12010077. [PMID: 35053225 PMCID: PMC8773825 DOI: 10.3390/biom12010077] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/23/2021] [Accepted: 12/29/2021] [Indexed: 12/18/2022] Open
Abstract
GAGs exhibit a high level of conformational and configurational diversity, which remains untapped in terms of the recognition and modulation of proteins. Although GAGs are suggested to bind to more than 800 biologically important proteins, very few therapeutics have been designed or discovered so far. A key challenge is the inability to identify, understand and predict distinct topologies accessed by GAGs, which may help design novel protein-binding GAG sequences. Recent studies on chondroitin sulfate (CS), a key member of the GAG family, pinpointing its role in multiple biological functions led us to study the conformational dynamism of CS building blocks using molecular dynamics (MD). In the present study, we used the all-atom GLYCAM06 force field for the first time to explore the conformational space of all possible CS building blocks. Each of the 16 disaccharides was solvated in a TIP3P water box with an appropriate number of counter ions followed by equilibration and a production run. We analyzed the MD trajectories for torsional space, inter- and intra-molecular H-bonding, bridging water, conformational spread and energy landscapes. An in-house phi and psi probability density analysis showed that 1→3-linked sequences were more flexible than 1→4-linked sequences. More specifically, phi and psi regions for 1→4-linked sequences were held within a narrower range because of intra-molecular H-bonding between the GalNAc O5 atom and GlcA O3 atom, irrespective of sulfation pattern. In contrast, no such intra-molecular interaction arose for 1→3-linked sequences. Further, the stability of 1→4-linked sequences also arose from inter-molecular interactions involving bridged water molecules. The energy landscape for both classes of CS disaccharides demonstrated increased ruggedness as the level of sulfation increased. The results show that CS building blocks present distinct conformational dynamism that offers the high possibility of unique electrostatic surfaces for protein recognition. The fundamental results presented here will support the development of algorithms that help to design longer CS chains for protein recognition.
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GAG-DB, the New Interface of the Three-Dimensional Landscape of Glycosaminoglycans. Biomolecules 2020; 10:biom10121660. [PMID: 33322545 PMCID: PMC7763844 DOI: 10.3390/biom10121660] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 12/18/2022] Open
Abstract
Glycosaminoglycans (GAGs) are complex linear polysaccharides. GAG-DB is a curated database that classifies the three-dimensional features of the six mammalian GAGs (chondroitin sulfate, dermatan sulfate, heparin, heparan sulfate, hyaluronan, and keratan sulfate) and their oligosaccharides complexed with proteins. The entries are structures of GAG and GAG-protein complexes determined by X-ray single-crystal diffraction methods, X-ray fiber diffractometry, solution NMR spectroscopy, and scattering data often associated with molecular modeling. We designed the database architecture and the navigation tools to query the database with the Protein Data Bank (PDB), UniProtKB, and GlyTouCan (universal glycan repository) identifiers. Special attention was devoted to the description of the bound glycan ligands using simple graphical representation and numerical format for cross-referencing to other databases in glycoscience and functional data. GAG-DB provides detailed information on GAGs, their bound protein ligands, and features their interactions using several open access applications. Binding covers interactions between monosaccharides and protein monosaccharide units and the evaluation of quaternary structure. GAG-DB is freely available.
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Mou J, Li Q, Shi W, Qi X, Song W, Yang J. Chain conformation, physicochemical properties of fucosylated chondroitin sulfate from sea cucumber Stichopus chloronotus and its in vitro fermentation by human gut microbiota. Carbohydr Polym 2020; 228:115359. [DOI: 10.1016/j.carbpol.2019.115359] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 12/18/2022]
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Nagarajan B, Sankaranarayanan NV, Desai UR. Perspective on computational simulations of glycosaminoglycans. WILEY INTERDISCIPLINARY REVIEWS. COMPUTATIONAL MOLECULAR SCIENCE 2019; 9:e1388. [PMID: 31080520 PMCID: PMC6504973 DOI: 10.1002/wcms.1388] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/07/2018] [Indexed: 01/06/2023]
Abstract
Glycosaminoglycans (GAGs) represent a formidable frontier for chemists, biochemists, biologists, medicinal chemists and drug delivery specialists because of massive structural complexity. GAGs are arguably the most complex, natural linear biopolymers with theoretical diversity orders of magnitude higher than proteins and nucleic acids. Yet, this diversity remains generally untapped. Computational approaches offer major routes to understand GAG structure and dynamics so as to enable novel applications of these biopolymers. In fact, computational algorithms, softwares, online tools and techniques have reached a level of sophistication that help understand atomistic details of conformational variation and protein recognition of individual GAG sequences. This review describes current approaches and challenges in computational study of GAGs. It presents a history of major findings since the earliest mention of GAGs (the 1960s), the development of parameters and force fields specific for GAGs, and the application of these tools in understanding GAG structure-function relationship. This review also presents a section on how to perform simulation of GAGs, which is directed toward researchers interested in entering this promising field with potential to impact therapy.
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Affiliation(s)
- Balaji Nagarajan
- Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond,
VA 23298, USA
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Nehru Viji Sankaranarayanan
- Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond,
VA 23298, USA
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Umesh R. Desai
- Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond,
VA 23298, USA
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA
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Profant V, Johannessen C, Blanch EW, Bouř P, Baumruk V. Effects of sulfation and the environment on the structure of chondroitin sulfate studied via Raman optical activity. Phys Chem Chem Phys 2019; 21:7367-7377. [DOI: 10.1039/c9cp00472f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Raman optical activity reflects differences in the secondary structure of chondroitin caused by its sulfation.
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Affiliation(s)
- Václav Profant
- Institute of Physics
- Faculty of Mathematics and Physics
- Charles University
- 121 16 Prague 2
- Czech Republic
| | | | | | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences
- 166 10 Prague 6
- Czech Republic
| | - Vladimír Baumruk
- Institute of Physics
- Faculty of Mathematics and Physics
- Charles University
- 121 16 Prague 2
- Czech Republic
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8
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Zsila F, Juhász T, Kohut G, Beke-Somfai T. Heparin and Heparan Sulfate Binding of the Antiparasitic Drug Imidocarb: Circular Dichroism Spectroscopy, Isothermal Titration Calorimetry, and Computational Studies. J Phys Chem B 2018; 122:1781-1791. [DOI: 10.1021/acs.jpcb.7b08876] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Ferenc Zsila
- Biomolecular Self-Assembly
Group, Institute of Materials and Environmental Chemistry, Research
Centre for Natural Sciences, Hungarian Academy of Sciences, H-1117 Budapest, Hungary
| | - Tünde Juhász
- Biomolecular Self-Assembly
Group, Institute of Materials and Environmental Chemistry, Research
Centre for Natural Sciences, Hungarian Academy of Sciences, H-1117 Budapest, Hungary
| | - Gergely Kohut
- Biomolecular Self-Assembly
Group, Institute of Materials and Environmental Chemistry, Research
Centre for Natural Sciences, Hungarian Academy of Sciences, H-1117 Budapest, Hungary
| | - Tamás Beke-Somfai
- Biomolecular Self-Assembly
Group, Institute of Materials and Environmental Chemistry, Research
Centre for Natural Sciences, Hungarian Academy of Sciences, H-1117 Budapest, Hungary
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An accurate coarse-grained model for chitosan polysaccharides in aqueous solution. PLoS One 2017; 12:e0180938. [PMID: 28732036 PMCID: PMC5521771 DOI: 10.1371/journal.pone.0180938] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/24/2017] [Indexed: 01/25/2023] Open
Abstract
Computational models can provide detailed information about molecular conformations and interactions in solution, which is currently inaccessible by other means in many cases. Here we describe an efficient and precise coarse-grained model for long polysaccharides in aqueous solution at different physico-chemical conditions such as pH and ionic strength. The Model is carefully constructed based on all-atom simulations of small saccharides and metadynamics sampling of the dihedral angles in the glycosidic links, which represent the most flexible degrees of freedom of the polysaccharides. The model is validated against experimental data for Chitosan molecules in solution with various degree of deacetylation, and is shown to closely reproduce the available experimental data. For long polymers, subtle differences of the free energy maps of the glycosidic links are found to significantly affect the measurable polymer properties. Therefore, for titratable monomers the free energy maps of the corresponding links are updated according to the current charge of the monomers. We then characterize the microscopic and mesoscopic structural properties of large chitosan polysaccharides in solution for a wide range of solvent pH and ionic strength, and investigate the effect of polymer length and degree and pattern of deacetylation on the polymer properties.
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Ng C, Nandha Premnath P, Guvench O. Rigidity and flexibility in the tetrasaccharide linker of proteoglycans from atomic-resolution molecular simulation. J Comput Chem 2017; 38:1438-1446. [PMID: 28101951 DOI: 10.1002/jcc.24738] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/12/2016] [Accepted: 12/20/2016] [Indexed: 01/09/2023]
Abstract
Proteoglycans (PGs) are covalent conjugates between protein and carbohydrate (glycosaminoglycans). Certain classes of glycosaminoglycans such as chondroitin sulfate/dermatan sulfate and heparan sulfate utilize a specific tetrasaccharide linker for attachment to the protein component: GlcAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser. Toward understanding the conformational preferences of this linker, the present work used all-atom explicit-solvent molecular dynamics (MD) simulations combined with Adaptive Biasing Force (ABF) sampling to determine high-resolution, high-precision conformational free energy maps ΔG(φ, ψ) for each glycosidic linkage between constituent disaccharides, including the variant where GlcA is substituted with IdoA. These linkages are characterized by single, predominant (> 97% occupancy), and broad (45° × 60° for ΔG(φ, ψ) < 1 kcal/mol) free-energy minima, while the Xyl-Ser linkage has two such minima similar in free-energy, and additional flexibility from the Ser sidechain dihedral. Conformational analysis of microsecond-scale standard MD on the complete tetrasaccharide-O-Ser conjugate is consistent with ABF data, suggesting (φ, ψ) probabilities are independent of the linker context, and that the tetrasaccharide acts as a relatively rigid unit whereas significant conformational heterogeneity exists with respect to rotation about bonds connecting Xyl to Ser. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Cathy Ng
- Department of Pharmaceutical Sciences, University of New England College of Pharmacy, 716 Stevens Avenue, Portland, Maine, 04103
| | - Padmavathy Nandha Premnath
- Department of Pharmaceutical Sciences, University of New England College of Pharmacy, 716 Stevens Avenue, Portland, Maine, 04103
| | - Olgun Guvench
- Department of Pharmaceutical Sciences, University of New England College of Pharmacy, 716 Stevens Avenue, Portland, Maine, 04103.,Graduate School of Biomedical Science and Engineering, University of Maine, 5775 Stodder Hall, Orono, Maine, 04469
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11
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Wu D, Ensinas A, Verrier B, Primard C, Cuvillier A, Champier G, Paul S, Delair T. Zinc-Stabilized Chitosan-Chondroitin Sulfate Nanocomplexes for HIV-1 Infection Inhibition Application. Mol Pharm 2016; 13:3279-91. [PMID: 27454202 DOI: 10.1021/acs.molpharmaceut.6b00568] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Polyelectrolyte complexes (PECs) constituted of chitosan and chondroitin sulfate (ChonS) were formed by the one-shot addition of default amounts of polyanion to an excess of polycation. Key variables of the formulation process (e.g., degree of depolymerization, charge mixing ratio, the concentration, and pH of polyelectrolyte solutions) were optimized based on the PECs sizes and polydispersities. The PECs maintained their colloidal stability at physiological salt concentration and pH thanks to the complexation of polyelectrolytes with zinc(II) ion during the nanoPECs formation process. The PECs were capable of encapsulating an antiretroviral drug tenofovir (TF) with a minimal alteration on the colloidal stability of the dispersion. Moreover, the particle interfaces could efficiently be functionalized with anti-OVA or anti-α4β7 antibodies with conservation of the antibody biorecognition properties over 1 week of storage in PBS at 4 °C. In vitro cytotoxicity studies showed that zinc(II) stabilized chitosan-ChonS nanoPECs were noncytotoxic to human peripheral blood mononuclear cells (PBMCs), and in vitro antiviral activity test demonstrated that nanoparticles formulations led to a dose-dependent reduction of HIV-1 infection. Using nanoparticles as a drug carrier system decreases the IC50 (50% inhibitory concentration) from an aqueous TF of 4.35 μmol·L(-1) to 1.95 μmol·L(-1). Significantly, zinc ions in this system also exhibited a synergistic effect in the antiviral potency. These data suggest that chitosan-ChonS nanoPECs can be promising drug delivery system to improve the antiviral potency of drugs to the viral reservoirs for the treatment of HIV infection.
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Affiliation(s)
- Danjun Wu
- Ingénierie des Matériaux Polymères, UMR CNRS 5223, Université Claude Bernard Lyon 1 , 15 Bd. André Latarjet, 69622 Villeurbanne Cedex, France
| | - Agathe Ensinas
- Institut de Biologie et Chimie des Protéines UMR 5305, CNRS/Université de Lyon , 69367 Lyon Cedex 07, France
| | - Bernard Verrier
- Institut de Biologie et Chimie des Protéines UMR 5305, CNRS/Université de Lyon , 69367 Lyon Cedex 07, France
| | | | | | - Gaël Champier
- B-Cell Design , 98 Rue Charles Legendre, 87000 Limoges, France
| | - Stephane Paul
- Groupe Immunité des Muqueuses et Agents Pathogènes, INSERM Centre d'Investigation Clinique en Vaccinologie 1408, Université de Lyon , 15 rue Ambroise Paré, 42023 Saint-Etienne Cedex 2, France
| | - Thierry Delair
- Ingénierie des Matériaux Polymères, UMR CNRS 5223, Université Claude Bernard Lyon 1 , 15 Bd. André Latarjet, 69622 Villeurbanne Cedex, France
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Mihov D, Spiess M. Glycosaminoglycans: Sorting determinants in intracellular protein traffic. Int J Biochem Cell Biol 2015; 68:87-91. [PMID: 26327396 DOI: 10.1016/j.biocel.2015.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 07/29/2015] [Accepted: 08/27/2015] [Indexed: 01/12/2023]
Abstract
Intracellular transport of proteins to their appropriate destinations is crucial for the maintenance of cellular integrity and function. Sorting information is contained either directly in the amino acid sequence or in a protein's post-translational modifications. Glycosaminoglycans (GAGs) are characteristic modifications of proteoglycans. GAGs are long unbranched polysaccharide chains with unique structural and functional properties also contributing to protein sorting in various ways. By deletion or insertion of GAG attachment sites it has been shown that GAGs affect polarized sorting in epithelial cells, targeting to and storage in secretory granules, and endocytosis. Most recently, the role of GAGs as signals for rapid trans-Golgi-to-cell surface transport, dominant over the cytosolic sorting motifs in the core protein, was demonstrated. Here, we provide an overview on existing data on the roles of GAGs on protein and proteoglycan trafficking.
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Affiliation(s)
- Deyan Mihov
- Biozentrum, University of Basel, Basel, Switzerland.
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Zsila F. Glycosaminoglycan and DNA Binding Induced Intra- and Intermolecular Exciton Coupling of thebis-4-Aminoquinoline Surfen. Chirality 2015; 27:605-12. [DOI: 10.1002/chir.22471] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/28/2015] [Indexed: 02/02/2023]
Affiliation(s)
- Ferenc Zsila
- Research Group of Chemical Biology; Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences; Budapest Hungary
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14
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Mihov D, Raja E, Spiess M. Chondroitin Sulfate Accelerates Trans-Golgi-to-Surface Transport of Proteoglycan Amyloid Precursor Protein. Traffic 2015; 16:853-70. [PMID: 25951880 DOI: 10.1111/tra.12294] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 04/15/2015] [Accepted: 04/15/2015] [Indexed: 11/28/2022]
Abstract
The amyloid precursor protein (APP) is a membrane protein implicated in the pathogenesis of Alzheimer's disease. APP is a part-time proteoglycan, as splice variants lacking exon 15 are modified by a chondroitin sulfate glycosaminoglycan (GAG) chain. Investigating the effect of the GAG chain on the trafficking of APP in non-polarized cells, we found it to increase the steady-state surface-to-intracellular distribution, to reduce the rate of endocytosis and to accelerate transport kinetics from the trans-Golgi network (TGN) to the plasma membrane. Deletion of the cytosolic domain resulted in delayed surface arrival of GAG-free APP, but did not affect the rapid export kinetics of the proteoglycan form. Protein-free GAG chains showed the same TGN-to-cell surface transport kinetics as proteoglycan APP. Endosome ablation experiments were performed to distinguish between indirect endosomal and direct pathways to the cell surface. Surprisingly, TGN-to-cell surface transport of both GAG-free and proteoglycan APP was found to be indirect via transferrin-positive endosomes. Our results show that GAGs act as alternative sorting determinants in cellular APP transport that are dominant over cytoplasmic signals and involve distinct sorting mechanisms.
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Affiliation(s)
- Deyan Mihov
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
| | - Eva Raja
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
| | - Martin Spiess
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
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Faller CE, Guvench O. Sulfation and cation effects on the conformational properties of the glycan backbone of chondroitin sulfate disaccharides. J Phys Chem B 2015; 119:6063-73. [PMID: 25906376 DOI: 10.1021/jp511431q] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chondroitin sulfate (CS) is one of several glycosaminoglycans that are major components of proteoglycans. A linear polymer consisting of repeats of the disaccharide -4GlcAβ1-3GalNAcβ1-, CS undergoes differential sulfation resulting in five unique sulfation patterns. Because of the dimer repeat, the CS glycosidic "backbone" has two distinct sets of conformational degrees of freedom defined by pairs of dihedral angles: (ϕ1, ψ1) about the β1-3 glycosidic linkage and (ϕ2, ψ2) about the β1-4 glycosidic linkage. Differential sulfation and the possibility of cation binding, combined with the conformational flexibility and biological diversity of CS, complicate experimental efforts to understand CS three-dimensional structures at atomic resolution. Therefore, all-atom explicit-solvent molecular dynamics simulations with Adaptive Biasing Force sampling of the CS backbone were applied to obtain high-resolution, high-precision free energies of CS disaccharides as a function of all possible backbone geometries. All 10 disaccharides (β1-3 vs β1-4 linkage × five different sulfation patterns) were studied; additionally, ion effects were investigated by considering each disaccharide in the presence of either neutralizing sodium or calcium cations. GlcAβ1-3GalNAc disaccharides have a single, broad, thermodynamically important free-energy minimum, whereas GalNAcβ1-4GlcA disaccharides have two such minima. Calcium cations but not sodium cations bind to the disaccharides, and binding is primarily to the GlcA -COO(-) moiety as opposed to sulfate groups. This binding alters the glycan backbone thermodynamics in instances where a calcium cation bound to -COO(-) can act to bridge and stabilize an interaction with an adjacent sulfate group, whereas, in the absence of this cation, the proximity of a sulfate group to -COO(-) results in two like charges being both desolvated and placed adjacent to each other and is found to be destabilizing. In addition to providing information on sulfation and cation effects, the present results can be applied to building models of CS polymers and as a point of comparison in studies of CS polymer backbone dynamics and thermodynamics.
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Affiliation(s)
- Christina E Faller
- Department of Pharmaceutical Sciences, University of New England College of Pharmacy, 716 Stevens Avenue, Portland, Maine 04103, United States
| | - Olgun Guvench
- Department of Pharmaceutical Sciences, University of New England College of Pharmacy, 716 Stevens Avenue, Portland, Maine 04103, United States
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Multilayered Thin Films from Boronic Acid-Functional Poly(amido amine)s. Pharm Res 2015; 32:3066-86. [PMID: 25851410 PMCID: PMC4526598 DOI: 10.1007/s11095-015-1688-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/23/2015] [Indexed: 01/24/2023]
Abstract
PURPOSE To investigate the properties of phenylboronic acid-functional poly(amido amine) polymers (BA-PAA) in forming multilayered thin films with poly(vinyl alcohol) (PVA) and chondroitin sulfate (ChS), and to evaluate their compatibility with COS-7 cells. METHODS Copolymers of phenylboronic acid-functional poly(amido amine)s, differing in the content of primary amine (DAB-BA-PAA) or alcohol (ABOL-BA-PAA) side groups, were synthesized and applied in the formation of multilayers with PVA and ChS. Biocompatibility of the resulting films was evaluated through cell culture experiments with COS-7 cells grown on the films. RESULTS PVA-based multilayers were thin, reaching ~100 nm at 10 bilayers, whereas ChS-based multilayers were thick, reaching ~600 nm at the same number of bilayers. All of the multilayers are stable under physiological conditions in vitro and are responsive to reducing agents, owing to the presence of disulfide bonds in the polymers. PVA-based films were demonstrated to be responsive to glucose at physiological pH at the investigated glucose concentrations (10-100 mM). The multilayered films displayed biocompatibility in cell culture experiments, promoting attachment and proliferation of COS-7 cells. CONCLUSIONS Responsive thin films based on boronic acid functional poly(amido amine)s are promising biocompatible materials for biomedical applications, such as drug releasing surfaces on stents or implants. Graphical Abstract Layer-by-Layer Assembly.
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Effects of Chondroitin Sulfate and Its Oligosaccharides on Toll-Like Receptor-Mediated IL-6 Secretion by Macrophage-Like J774.1 Cells. Biosci Biotechnol Biochem 2014; 75:1283-9. [DOI: 10.1271/bbb.110055] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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18
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Solution NMR conformation of glycosaminoglycans. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 114:61-8. [DOI: 10.1016/j.pbiomolbio.2014.01.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/10/2014] [Accepted: 01/17/2014] [Indexed: 11/18/2022]
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Abstract
The extracellular space (ECS) consists of the narrow channels between brain cells together with their geometrical configuration and contents. Despite being only 20-60 nm in width, the ECS typically occupies 20% of the brain volume. Numerous experiments over the last 50 years have established that molecules moving through the ECS obey the laws of diffusion but with an effective diffusion coefficient reduced by a factor of about 2.6 compared to free diffusion. This review considers the origins of the diffusion barrier arising from the ECS and its properties. The paper presents a brief overview of software for implementing two point-source paradigms for measurements of localized diffusion properties: the real-time iontophoresis or pressure method for small ions and the integrative optical imaging method for macromolecules. Selected results are presented. This is followed by a discussion of the application of the MCell Monte Carlo simulation program to determining the importance of geometrical constraints, especially dead-space microdomains, and the possible role of interaction with the extracellular matrix. It is concluded that we can predict the impediment to diffusion of many molecules of practical importance and also use studies of the diffusion of selected molecular probes to reveal the barrier properties of the ECS.
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Cilpa G, Hyvönen MT, Koivuniemi A, Riekkola ML. Atomistic insight into chondroitin-6-sulfate glycosaminoglycan chain through quantum mechanics calculations and molecular dynamics simulation. J Comput Chem 2010; 31:1670-80. [PMID: 20087899 DOI: 10.1002/jcc.21453] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chondroitin-6-sulfate (C6S) is a glycosaminoglycan (GAG) constituent in the extracellular matrix, which participates actively in crucial biological processes, as well as in various pathological conditions, such as atherosclerosis and cancer. Molecular interactions involving the C6S chain are therefore of considerable interest. A computational model for atomistic simulation was built. This work describes the design and validation of a force field for a C6S dodecasaccharide chain. The results of an extensive molecular dynamics simulation performed with the new force field provide a novel insight into the structure and dynamics of the C6S chain. The intramolecular H-bonds in the disaccharide linkage region are suggested to play a major role in determining the chain structural dynamics. Moreover, the unravelling of an additional H-bond involving the sulfate groups in C6S is interesting as changes in sulfation have been claimed to be an important factor in several diseases. The force field will prove useful for future studies of crucial interactions between C6S and various nanoassemblies. It can also be used as a basis for modeling of other GAGs.
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Affiliation(s)
- G Cilpa
- Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland.
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21
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Valle‐Delgado JJ, Alfonso‐Prieto M, Groot NS, Ventura S, Samitier J, Rovira C, Fernàndez‐Busquets X. Modulation of Aβ
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fìbrillogenesis by glycosaminoglycan structure. FASEB J 2010; 24:4250-61. [DOI: 10.1096/fj.09-153551] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Juan José Valle‐Delgado
- Nanobioengineering GroupInstitute for Bioengineering of Catalonia Barcelona Spain
- Biomolecular Interactions TeamNanoscience and Nanotechnology Institute Barcelona Spain
| | - Mercedes Alfonso‐Prieto
- Institut de Química Teòrica i Computacional Barcelona Spain
- Computer Simulation and Modeling Laboratory (CoSMo LAB) Barcelona Spain
| | - Natalia S. Groot
- Institut de Biotecnologia i de BiomedicinaDepartament de Bioquímica i Biologia MolecularUniversitat Autònoma de Barcelona Barcelona Spain
| | - Salvador Ventura
- Institut de Biotecnologia i de BiomedicinaDepartament de Bioquímica i Biologia MolecularUniversitat Autònoma de Barcelona Barcelona Spain
| | - Josep Samitier
- Nanobioengineering GroupInstitute for Bioengineering of Catalonia Barcelona Spain
- Department of ElectronicsUniversity of Barcelona Barcelona Spain
| | - Carme Rovira
- Institut de Química Teòrica i Computacional Barcelona Spain
- Computer Simulation and Modeling Laboratory (CoSMo LAB) Barcelona Spain
- Institució Catalana de Recerca i Estudis Avançats Barcelona Spain
| | - Xavier Fernàndez‐Busquets
- Nanobioengineering GroupInstitute for Bioengineering of Catalonia Barcelona Spain
- Biomolecular Interactions TeamNanoscience and Nanotechnology Institute Barcelona Spain
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22
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Sattelle BM, Shakeri J, Roberts IS, Almond A. A 3D-structural model of unsulfated chondroitin from high-field NMR: 4-sulfation has little effect on backbone conformation. Carbohydr Res 2009; 345:291-302. [PMID: 20022001 PMCID: PMC3098369 DOI: 10.1016/j.carres.2009.11.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 11/06/2009] [Accepted: 11/10/2009] [Indexed: 11/26/2022]
Abstract
The glycosaminoglycan chondroitin sulfate is essential in human health and disease but exactly how sulfation dictates its 3D-structure at the atomic level is unclear. To address this, we have purified homogenous oligosaccharides of unsulfated chondroitin (with and without (15)N-enrichment) and analysed them by high-field NMR to make a comparison published chondroitin sulfate and hyaluronan 3D-structures. The result is the first full assignment of the tetrasaccharide and an experimental 3D-model of the hexasaccharide (PDB code 2KQO). In common with hyaluronan, we confirm that the amide proton is not involved in strong, persistent inter-residue hydrogen bonds. However, in contrast to hyaluronan, a hydrogen bond is not inferred between the hexosamine OH-4 and the glucuronic acid O5 atoms across the beta(1-->3) glycosidic linkage. The unsulfated chondroitin bond geometry differs slightly from hyaluronan by rotation about the beta(1-->3) psi dihedral (as previously predicted by simulation), while the beta(1-->4) linkage is unaffected. Furthermore, comparison shows that this glycosidic linkage geometry is similar in chondroitin-4-sulfate. We therefore hypothesise that both hexosamine OH-4 and OH-6 atoms are solvent exposed in chondroitin, explaining why it is amenable to sulfation and hyaluronan is not, and also that 4-sulfation has little effect on backbone conformation. Our conclusions exemplify the value of the 3D-model presented here and progress our understanding of glycosaminoglycan molecular properties.
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Affiliation(s)
- Benedict M Sattelle
- Manchester Interdisciplinary Biocentre, 131 Princess Street, Manchester, M1 7DN, UK
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23
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Hrabetová S, Masri D, Tao L, Xiao F, Nicholson C. Calcium diffusion enhanced after cleavage of negatively charged components of brain extracellular matrix by chondroitinase ABC. J Physiol 2009; 587:4029-49. [PMID: 19546165 DOI: 10.1113/jphysiol.2009.170092] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The concentration of extracellular calcium plays a critical role in synaptic transmission and neuronal excitability as well as other physiological processes. The time course and extent of local fluctuations in the concentration of this ion largely depend on its effective diffusion coefficient (D*) and it has been speculated that fixed negative charges on chondroitin sulphate proteoglycans (CSPGs) and other components of the extracellular matrix may influence calcium diffusion because it is a divalent cation. In this study we used ion-selective microelectrodes combined with pressure ejection or iontophoresis of ions from a micropipette to quantify diffusion characteristics of neocortex and hippocampus in rat brain slices. We show that D* for calcium is less than the value predicted from the behaviour of the monovalent cation tetramethylammonium (TMA), a commonly used diffusion probe, but D* for calcium increases in both brain regions after the slices are treated with chondroitinase ABC, an enzyme that predominantly cleaves chondroitin sulphate glycans. These results suggest that CSPGs do play a role in determining the local diffusion properties of calcium in brain tissue, most likely through electrostatic interactions mediating rapid equilibrium binding. In contrast, chondroitinase ABC does not affect either the TMA diffusion or the extracellular volume fraction, indicating that the enzyme does not alter the structure of the extracellular space and that the diffusion of small monovalent cations is not affected by CSPGs in the normal brain ionic milieu. Both calcium and CSPGs are known to have many distinct roles in brain physiology, including brain repair, and our study suggests they may be functionally coupled through calcium diffusion properties.
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Affiliation(s)
- Sabina Hrabetová
- Department of Physiology and Neuroscience, NYU School of Medicine, 550 First Avenue, New York, NY 10016, USA
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24
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Loret B, Simões FMF. Effects of pH on transport properties of articular cartilages. Biomech Model Mechanobiol 2009; 9:45-63. [PMID: 19418080 DOI: 10.1007/s10237-009-0158-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Accepted: 04/16/2009] [Indexed: 11/25/2022]
Abstract
Articular cartilages swell and shrink depending on the ionic strength of the electrolyte they are in contact with. This electro-chemo-mechanical coupling is due to the presence of fixed electrical charges on proteoglycans (PGs). In addition, at nonphysiological pH, collagen fibers become charged. Therefore, variation of the pH of the electrolyte has strong implications on the electrical charge of cartilages and, by the same token, on their transport and mechanical properties. Articular cartilages are viewed as three-phase multi-species porous media. The constitutive framework is phrased in the theory of thermodynamics of porous media. Acid-base reactions, as well as calcium binding, are embedded in this framework. Although macroscopic in nature, the model accounts for a number of biochemical details defining collagen and PGs. The change of the electrical charge is due to the binding of hydrogen ions on specific sites of PGs and collagen. Simulations are performed mimicking laboratory experiments where either the ionic strength or the pH of the bath, the cartilage piece is in contact with, is varied. They provide the evolutions of the chemical compositions of mobile ions, of the sites of acid-base reactions and calcium binding, and of the charges of collagen and glycosaminoglycans, at constant volume fraction of water. Emphasis is laid on the effects of pH, ionic strength and calcium binding on the transport properties of cartilages, and, in particular, on the electrical conductivity and electro-osmotic coefficient.
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Affiliation(s)
- Benjamin Loret
- Laboratoire Sols, Solides, Structures, Institut National Polytechnique de Grenoble, B.P. 53X, 38041, Grenoble Cedex, France.
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25
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Crouzier T, Picart C. Ion Pairing and Hydration in Polyelectrolyte Multilayer Films Containing Polysaccharides. Biomacromolecules 2009; 10:433-42. [DOI: 10.1021/bm8012378] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas Crouzier
- Université de Montpellier 2, CNRS UMR 5539, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
| | - Catherine Picart
- Université de Montpellier 2, CNRS UMR 5539, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
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26
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Meziane-Tani M, Lagant P, Semmoud A, Vergoten G. The SPASIBA force field for chondroitin sulfate: vibrational analysis of D-glucuronic and N-acetyl-D-galactosamine 4-sulfate sodium salts. J Phys Chem A 2007; 110:11359-70. [PMID: 17004747 DOI: 10.1021/jp063862g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Normal-mode analyses were carried out on the two components of the chondroitin 4-sulfate linear glycosaminoglycan, a copolymer implying alternate D-glucuronate beta-(1-->3) and N-acetyl-D-galactosamine 4-sulfate beta-(1-->4) (hereafter named D-galactosamine 4-sulfate) residues. Scaled quantum mechanical calculations (SQM) using the density functional theory approach at different levels of theory (B3LYP/6-31G** and B3LYP/6-31++G**) were performed to obtain correct vibrational assignments. The SPASIBA empirical force field parameters were then obtained from both theoretical predictions and observed IR and Raman data. It is shown that calculations including diffuse functions at the B3LP/6-31++G** level and the introduction of the Na+ counterion are necessary to give correct assignments of the CO2- symmetric (nu(s)) and antisymmetric (nu(a)) stretching modes for the glucuronic carboxylate residue.
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Affiliation(s)
- M Meziane-Tani
- Département de Biologie, Faculté des Sciences, Université Abou Bekr Belkaid, 22 rue Abi Ayed Abdelkrim, Faubourg Pasteur, 13000 Tlemcen, Algérie
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27
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Yu F, Wolff JJ, Amster IJ, Prestegard JH. Conformational Preferences of Chondroitin Sulfate Oligomers Using Partially Oriented NMR Spectroscopy of 13C-Labeled Acetyl Groups. J Am Chem Soc 2007; 129:13288-97. [DOI: 10.1021/ja075272h] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fei Yu
- Contribution from the Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, Athens, Georgia 30602-4712
| | - Jeremy J. Wolff
- Contribution from the Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, Athens, Georgia 30602-4712
| | - I. Jonathan Amster
- Contribution from the Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, Athens, Georgia 30602-4712
| | - James H. Prestegard
- Contribution from the Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, Athens, Georgia 30602-4712
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28
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Blanchard V, Chevalier F, Imberty A, Leeflang BR, Sugahara K, Kamerling JP. Conformational Studies on Five Octasaccharides Isolated from Chondroitin Sulfate Using NMR Spectroscopy and Molecular Modeling. Biochemistry 2007; 46:1167-75. [PMID: 17260946 DOI: 10.1021/bi061971f] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chondroitin sulfate proteoglycans (CS-PG) are involved in the regulation of the central nervous system in vertebrates due to their presence on cell surfaces and in the extracellular matrix of tissues. The CS moieties are built up from repeating -4)GlcA(beta1-3)GalNAc(beta1- disaccharide units, partly O-sulfated at different positions. The presence of the disulfated disaccharide D-unit, GlcA2S(beta1-3)GalNAc6S, in the CS moiety of the proteoglycan DSD-1-PG/phosphacan, correlates with neurite outgrowth promotion. The binding of monoclonal antibody (mAb) 473HD to DSD-1-PG, reducing neuronal stimulation, is inhibited by shark cartilage CS-D. CS-D is also recognized by two other mAbs, MO-225 and CS-56. Conformational studies were performed using NMR spectroscopy and molecular modeling on five octasaccharides isolated from shark cartilage CS-D. These octasaccharides present different binding properties toward the three mAbs. The combination of the experimental and theoretical approaches revealed that the sulfate group at position 2 of GlcA in disaccharide D and the presence of an exocyclic negative tail in disaccharides C [GlcA(beta1-3)GalNAc6S] and DeltaC [Delta4,5HexA(alpha1-3)GalNAc6S] are important for antibody recognition.
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Affiliation(s)
- Véronique Blanchard
- Bijvoet Center, Department of Bio-Organic Chemistry, Utrecht University, Padualaan 8, NL-3584 CH Utrecht, The Netherlands
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29
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Siebert HC, Rosen J, Seyrek K, Kaltner H, André S, Bovin NV, Nyholm PG, Sinowatz F, Gabius HJ. α2,3/α2,6-Sialylation of N-glycans: non-synonymous signals with marked developmental regulation in bovine reproductive tracts. Biochimie 2006; 88:399-410. [PMID: 16360259 DOI: 10.1016/j.biochi.2005.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2005] [Accepted: 09/23/2005] [Indexed: 10/25/2022]
Abstract
The glycan part endows cellular glycoconjugates with significant potential for biological recognition. N-Glycan branches often end with alpha2,3/alpha2,6-sialylation, posing the question whether and how placement of the sialic acid at 3 - or 6 -acceptor positions of galactose has cell biological relevance. As attractive model to study developmental regulation we monitored the expression of alpha2,3/alpha2,6-sialylated determinants in fetal and adult bovine testes and ovaries by lectin histochemistry. Distinct expression patterns were detected in both organ types. Oocyte staining, as a prominent example, was restricted to the presence of alpha2,6-sialylated glycans. Treatment with sialidase abolished binding and thus excluded sulfate esters as lectin targets. We added computer simulations to rationalize the observed evidence for non-random expression of the two closely related sialylgalactose isomers. Extensive molecular mechanics and molecular dynamics calculations reveal that the seemingly minor shift of the glycosidic bond from the alpha2,3 position to the alpha2,6 configuration causes significant shape and flexibility changes. They give each disaccharide its own characteristic meaning as signal in the sugar code.
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Affiliation(s)
- Hans-Christian Siebert
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539 München, Germany
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30
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Jiang H, Liu XY, Zhang G, Li Y. Kinetics and Template Nucleation of Self-Assembled Hydroxyapatite Nanocrystallites by Chondroitin Sulfate. J Biol Chem 2005; 280:42061-6. [PMID: 16251185 DOI: 10.1074/jbc.m412280200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biomineralization is an important process, which is often assisted by biomolecules. In this paper, the effect of chondroitin sulfate on the crystallization of hydroxyapatite was examined quantitatively based on a generic heterogeneous nucleation model. It is found that chondroitin sulfate can suppress the supersaturation-driven interfacial structure mismatch between the hydroxyapatite crystal and the substrate and promote the formation of ordered hydroxyapatite nanocrystallite assemblies. The nucleation mechanism of self-aligned hydroxyapatite nanocrystallites was examined from the viewpoints of kinetics and interfacial structure and properties, which contributes to an understanding of the fundamentals of biomineralization of self-assembled structures. The results obtained from this study will provide a basic principle to design and fabricate highly orderly organic-inorganic hybrid materials.
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Affiliation(s)
- Huaidong Jiang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542
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31
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Bathe M, Rutledge GC, Grodzinsky AJ, Tidor B. Osmotic pressure of aqueous chondroitin sulfate solution: a molecular modeling investigation. Biophys J 2005; 89:2357-71. [PMID: 16055525 PMCID: PMC1366736 DOI: 10.1529/biophysj.105.067918] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The osmotic pressure of chondroitin sulfate (CS) solution in contact with an aqueous 1:1 salt reservoir of fixed ionic strength is studied using a recently developed coarse-grained molecular model. The effects of sulfation type (4- vs. 6-sulfation), sulfation pattern (statistical distribution of sulfate groups along a chain), ionic strength, CS intrinsic stiffness, and steric interactions on CS osmotic pressure are investigated. At physiological ionic strength (0.15 M NaCl), the sulfation type and pattern, as measured by a standard statistical description of copolymerization, are found to have a negligible influence on CS osmotic pressure, which depends principally on the mean volumetric fixed charge density. The intrinsic backbone stiffness characteristic of polysaccharides such as CS, however, is demonstrated to contribute significantly to its osmotic pressure behavior, which is similar to that of a solution of charged rods for the 20-disaccharide chains considered. Steric excluded volume is found to play a negligible role in determining CS osmotic pressure at physiological ionic strength due to the dominance of repulsive intermolecular electrostatic interactions that maintain chains maximally spaced in that regime, whereas at high ionic-strength steric interactions become dominant due to electrostatic screening. Osmotic pressure predictions are compared to experimental data and to well-established theoretical models including the Donnan theory and the Poisson-Boltzmann cylindrical cell model.
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Affiliation(s)
- Mark Bathe
- Department of Mechanical Engineering, the Massachusetts Institute of Technology, Cambridge, MA, USA
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32
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Properzi F, Carulli D, Asher RA, Muir E, Camargo LM, van Kuppevelt TH, ten Dam GB, Furukawa Y, Mikami T, Sugahara K, Toida T, Geller HM, Fawcett JW. Chondroitin 6-sulphate synthesis is up-regulated in injured CNS, induced by injury-related cytokines and enhanced in axon-growth inhibitory glia. Eur J Neurosci 2005; 21:378-90. [PMID: 15673437 DOI: 10.1111/j.1460-9568.2005.03876.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chondroitin sulphate proteoglycans (CSPGs) are up-regulated in the CNS after injury and inhibit axon regeneration mainly through their glycosaminoglycan (CS-GAG) chains. We have analysed the mRNA levels of the CS-GAG synthesizing enzymes and measured the CS-GAG disaccharide composition by chromatography and immunocytochemistry. Chondroitin 6-sulfotransferase 1 (C6ST1) is up-regulated in most glial types around cortical injuries, and its sulphated product CS-C is also selectively up-regulated. Treatment with TGFalpha and TGFbeta, which are released after brain injury, promotes the expression of C6ST1 and the synthesis of 6-sulphated CS-GAGs in primary astrocytes. Oligodendrocytes, oligodendrocyte precursors and meningeal cells are all inhibitory to axon regeneration, and all express high levels of CS-GAG, including high levels of 6-sulphated GAG. In axon growth-inhibitory Neu7 astrocytes C6ST1 and 6-sulphated GAGs are expressed at high levels, whereas in permissive A7 astrocytes they are not detectable. These results suggest that the up-regulation of CSPG after CNS injury is associated with a specific sulphation pattern on CS-GAGs, mediating the inhibitory properties of proteoglycans on axonal regeneration.
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Affiliation(s)
- Francesca Properzi
- Centre for Brain Repair, Cambridge University, Forvie Site, Cambridge CB2 2PY, UK
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Bathe M, Rutledge GC, Grodzinsky AJ, Tidor B. A coarse-grained molecular model for glycosaminoglycans: application to chondroitin, chondroitin sulfate, and hyaluronic acid. Biophys J 2005; 88:3870-87. [PMID: 15805173 PMCID: PMC1305620 DOI: 10.1529/biophysj.104.058800] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A coarse-grained molecular model is presented for the study of the equilibrium conformation and titration behavior of chondroitin (CH), chondroitin sulfate (CS), and hyaluronic acid (HA)-glycosaminoglycans (GAGs) that play a central role in determining the structure and biomechanical properties of the extracellular matrix of articular cartilage. Systematic coarse-graining from an all-atom description of the disaccharide building blocks retains the polyelectrolytes' specific chemical properties while enabling the simulation of high molecular weight chains that are inaccessible to all-atom representations. Results are presented for the characteristic ratio, the ionic strength-dependent persistence length, the pH-dependent expansion factor for the end-to-end distance, and the titration behavior of the GAGs. Although 4-sulfation of the N-acetyl-D-galactosamine residue is found to increase significantly the intrinsic stiffness of CH with respect to 6-sulfation, only small differences in the titration behavior of the two sulfated forms of CH are found. Persistence length expressions are presented for each type of GAG using a macroscopic (wormlike chain-based) and a microscopic (bond vector correlation-based) definition. Model predictions agree quantitatively with experimental conformation and titration measurements, which support use of the model in the investigation of equilibrium solution properties of GAGs.
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Affiliation(s)
- Mark Bathe
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, 02139, USA
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