The Experts below are selected from a list of 1998 Experts worldwide ranked by ideXlab platform
Julie A. Leary - One of the best experts on this subject based on the ideXlab platform.
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Differentiation of CC vs CXC chemokine dimers with GAG Octasaccharide binding partners: an ion mobility mass spectrometry approach.
Journal of the American Chemical Society, 2013Co-Authors: Youjin Seo, Armann Andaya, Christian Bleiholder, Julie A. LearyAbstract:Chemokines, 8 kDa proteins implicated in leukocyte migration via oligomerization, bind to glycosaminoglycans (GAGs) during the inflammation response as a means to regulate chemokine migration. Structural characterization of chemokines non-covalently bound to GAGs provides physiologically meaningful data in regard to routine inmmunosurveillance and disease response. In order to analyze the structures resulting from the GAG:chemokine interaction, we employed ion mobility mass spectrometry (IMMS) to analyze monocyte chemoattractant protein-1 (MCP-1), a CC chemokine, and interleukin-8 (IL-8), a CXC chemokine, along with their individual interactions with GAG heparin Octasaccharides. We show that MCP-1 and IL-8 are physiologically present as a dimer, with MCP-1 having two variants of its dimeric form and IL-8 having only one. We also show that the MCP-1 dimer adopts two conformations, one extended and one compact, when bound to a dodecasulfated heparin Octasaccharide. Binding of MCP-1 to heparin Octasaccharide...
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Differentiation of CC vs CXC Chemokine Dimers with GAG Octasaccharide Binding Partners: An Ion Mobility Mass Spectrometry Approach
2013Co-Authors: Youjin Seo, Armann Andaya, Christian Bleiholder, Julie A. LearyAbstract:Chemokines, 8 kDa proteins implicated in leukocyte migration via oligomerization, bind to glycosaminoglycans (GAGs) during the inflammation response as a means to regulate chemokine migration. Structural characterization of chemokines non-covalently bound to GAGs provides physiologically meaningful data in regard to routine inmmunosurveillance and disease response. In order to analyze the structures resulting from the GAG:chemokine interaction, we employed ion mobility mass spectrometry (IMMS) to analyze monocyte chemoattractant protein‑1 (MCP‑1), a CC chemokine, and interleukin‑8 (IL‑8), a CXC chemokine, along with their individual interactions with GAG heparin Octasaccharides. We show that MCP‑1 and IL‑8 are physiologically present as a dimer, with MCP‑1 having two variants of its dimeric form and IL‑8 having only one. We also show that the MCP‑1 dimer adopts two conformations, one extended and one compact, when bound to a dodecasulfated heparin Octasaccharide. Binding of MCP‑1 to heparin Octasaccharide isomers of varying sulfation patterns results in similar arrival time distribution values, which suggests minimal distinguishing features among the resultant complexes. Additionally, tandem mass spectrometry (MS/MS) showed that the binding of MCP‑1 to a heparin Octasaccharide has different dissociation patterns when compared with the corresponding IL‑8 bound dimer. Overall, IMMS and MS/MS were used to better define the structural tendencies and differences associated with CC and CXC dimers when associated with GAG Octasaccharides
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Preparation, separation, and conformational analysis of differentially sulfated heparin Octasaccharide isomers using ion mobility mass spectrometry.
Analytical chemistry, 2012Co-Authors: Youjin Seo, Armann Andaya, Julie A. LearyAbstract:Heparin is a linear sulfated polysaccharide widely used in medicine because of its anticoagulant properties. The various sulfation and/or acetylation patterns on heparin impart different degrees of conformational change around the glycosidic bonds and subsequently alter its function as an anticoagulant, anticancer, or antiviral drug. Characterization of these structures is important for eventual elucidation of its function but presents itself as an analytical challenge due to the inherent heterogeneity of the carbohydrates. Heparin Octasaccharide structural isomers of various sulfation patterns were investigated using ion mobility mass spectrometry (IMMS). In addition to distinguishing the isomers, we report the preparation and tandem mass spectrometry analysis for multiple sulfated or acetylated oligosaccharides. Herein, our data indicate that heparin Octasaccharide isomers were separated on the basis of their structural conformations in the ion mobility cell. Subsequent to this separation, isomers were ...
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Biologically relevant metal-cation binding induces conformational changes in heparin oligosaccharides as measured by ion mobility mass spectrometry
International Journal of Mass Spectrometry, 2011Co-Authors: Youjin Seo, Matthew R. Schenauer, Julie A. LearyAbstract:Abstract Heparin interacts with many proteins and is involved in biological processes such as anticoagulation, angiogenesis, and antitumorigenic activities. These heparin–protein interactions can be influenced by the binding of various metal ions to these complexes. In particular, physiologically relevant metal cations influence heparin–protein conformations through electronic interactions inherent to this polyanion. In this study, we employed ion mobility mass spectrometry (IMMS) to observe conformational changes that occur in fully-sulfated heparin Octasaccharides after the successive addition of metal ions. Our results indicate that binding of positive counter ions causes a decrease in collision cross section (CCS) measurements, thus promoting a more compact Octasaccharide structure.
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CCR2 Chemokines Bind Selectively to Acetylated Heparan Sulfate Octasaccharides
The Journal of biological chemistry, 2007Co-Authors: Matthew R. Schenauer, Matthew Sweeney, Julie A. LearyAbstract:Chemokines participate in well documented interactions with glycosaminoglycans (GAGs). Although many chemokine amino acid residues involved in binding have been identified, much less is known about the bound regions of GAG. Heparan sulfate (HS) is the predominant cell surface GAG, and its heterogeneous nature offers proteins a variety of structural motifs with which to interact. In the present study, we describe the interactions of three CC chemokines, MCP-1/CCL2, MCP-2/CCL8, and MCP-3/CCL7, with HS-derived oligosaccharides. To this end, we generated and characterized a complex HS Octasaccharide library containing 17 different Octasaccharide compositions based on acetyl and sulfate group content. Electrospray ionization mass spectrometry was used to detect chemokine-HS Octasaccharide complexes in the bound state, and an affinity purification protocol was used to select and identify chemokine-binding Octasaccharides from the complex mixture. The results indicate that HS Octasaccharide sulfation is the foremost requirement for chemokine binding. However, within Octasaccharides of constant charge density, acetylation is also observed to augment binding, suggesting that there may be as yet undiscovered specificity in the chemokine-HS interaction.
Robert Seckler - One of the best experts on this subject based on the ideXlab platform.
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an essential serotype recognition pocket on phage p22 tailspike protein forces salmonella enterica serovar paratyphi a o antigen fragments to bind as nonsolution conformers
Glycobiology, 2013Co-Authors: Dorothee Andres, Ulrich Gohlke, Nina K Broeker, Stefan Schulze, Wolfgang Rabsch, Udo Heinemann, Stefanie Barbirz, Robert SecklerAbstract:In contrast, Octasaccharides from the other serotypes bind as solution-like conformers. Two water molecules are conserved in all P22 TSP complexes with Octasaccharides of different serotypes. They line the dideoxyhexose binding pocket and force the S. Paratyphi A Octasaccharides to bind as nonsolution conformers. This emphasizes the role of solvent as part of carbohydrate binding sites.
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Interaction of a Salmonella enteritidis O-antigen Octasaccharide with the phage P22 tailspike protein by NMR spectroscopy and docking studies
Glycoconjugate Journal, 2008Co-Authors: Jens Landström, Eva-lisa Nordmark, Robert Eklund, Andrej Weintraub, Robert Seckler, Göran WidmalmAbstract:The tailspike protein P22 recognizes an Octasaccharide derived from the O-antigen polysaccharide of Salmonella enteritidis in a shallow groove and molecular docking successfully identifies this binding region on the protein surface. Analysis by 2D ^1H,^1H-T-ROESY and transferred NOESY NMR experiments indicate that the bound Octasaccharide ligand has a conformation similar to that observed in solution. The results from a saturation transfer difference NMR experiment show that a large number of protons in the Octasaccharide are in close contact with the protein as a result of binding. A comparison of the crystal structure of the complex and a molecular dynamics simulation of the Octasaccharide with explicit water molecules suggest that only minor conformational changes are needed upon binding to the tailspike protein.
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Interaction of a Salmonella enteritidis O-antigen Octasaccharide with the phage P22 tailspike protein by NMR spectroscopy and docking studies
Glycoconjugate Journal, 2008Co-Authors: Jens Landström, Eva-lisa Nordmark, Robert Eklund, Andrej Weintraub, Robert Seckler, Göran WidmalmAbstract:The tailspike protein P22 recognizes an Octasaccharide derived from the O-antigen polysaccharide of Salmonella enteritidis in a shallow groove and molecular docking successfully identifies this binding region on the protein surface. Analysis by 2D ^1H,^1H-T-ROESY and transferred NOESY NMR experiments indicate that the bound Octasaccharide ligand has a conformation similar to that observed in solution. The results from a saturation transfer difference NMR experiment show that a large number of protons in the Octasaccharide are in close contact with the protein as a result of binding. A comparison of the crystal structure of the complex and a molecular dynamics simulation of the Octasaccharide with explicit water molecules suggest that only minor conformational changes are needed upon binding to the tailspike protein.
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Interaction studies of a Salmonella enteritidis O-antigen Octasaccharide to Phage P22 tail spike protein by NMR spectroscopy and molecular modelling
2004Co-Authors: Eva-lisa Nordmark, Robert Eklund, Andrej Weintraub, Robert Seckler, Göran WidmalmAbstract:Interaction studies of a Salmonella enteritidis O-antigen Octasaccharide to Phage P22 tail spike protein by NMR spectroscopy and molecular modelling
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mutations improving the folding of phage p22 tailspike protein affect its receptor binding activity
Journal of Molecular Biology, 1999Co-Authors: Ulrich Baxa, Andrej Weintraub, Stefan Steinbacher, Robert Huber, Robert SecklerAbstract:Abstract Four previously isolated mutations in Salmonella phage P22 tailspike protein were used to study the relationship between protein stability, folding, and function. Tailspike protein binds and hydrolyzes the repetitive O-antigen structure in Salmonella lipopolysaccharide. Four mutations (V331G, V331A, A334V, A334I) are known to increase the folding efficiency, and two of them (at position 331) also increase the thermal stability of the protein. Octasaccharides comprising two repeating units of the O-antigens from two different Salmonella strains were employed to analyze the receptor binding function of the mutant proteins. Their endorhamnosidase enzymatic activity was assayed with the aid of a fluorescence-labeled dodecasaccharide. Both V331A and V331G were found to strongly affect O-antigen binding. Octasaccharide binding affinities of the mutant proteins are reduced tenfold and 200-fold, corresponding to a loss of 17 % and 36 % of the standard free energy of binding, respectively. Both mutations at position 334 affected O-antigen binding only slightly (ΔΔGB03≈1 kJ/mol), but these mutations reduce the thermal stability of the protein. The observed effects on the endoglycosidase activity are fully explained by the changes in substrate binding, suggesting that neither of the mutations affect the catalytic rate. Crystal structures of all four mutants were determined to a resolution of 2.0 A. Except for the partly or completely missing side-chain, no significant changes compared to the wild-type protein structure were found for the mutants at position 331, whereas a small but significant backbone displacement around the mutation site in A334V and A334I may explain the observed thermal destabilization.
Jian Liu - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of 3‑O‑Sulfated Oligosaccharides to Understand the Relationship between Structures and Functions of Heparan Sulfate
2017Co-Authors: Zhangjie Wang, Po-hung Hsieh, David Thieker, Evangeline Juan En Chai, Shaoshuai Xie, Brian Cooley, Robert J. Woods, Lianli Chi, Jian LiuAbstract:The sulfation at the 3-OH position of glucosamine is an important modification in forming structural domains for heparan sulfate to enable its biological functions. Seven 3-O-sulfotransferase isoforms in the human genome are involved in the biosynthesis of 3-O-sulfated heparan sulfate. As a rare modification present in heparan sulfate, the availability of 3-O-sulfated oligosaccharides is very limited. Here, we report the use of a chemoenzymatic synthetic approach to synthesize six 3-O-sulfated oligosaccharides, including three hexasaccharides and three Octasaccharides. The synthesis was achieved by rearranging the enzymatic modification sequence to accommodate the substrate specificity of 3-O-sulfotransferase 3. We studied the impact of 3-O-sulfation on the conformation of the pyranose ring of 2-O-sulfated iduronic acid using NMR, and on the correlation between ring conformation and anticoagulant activity. We identified a novel Octasaccharide that interacts with antithrombin and displays anti factor Xa activity. Interestingly, the Octasaccharide displays a faster clearance rate than fondaparinux, an FDA-approved pentasaccharide drug, in a rat model, making this Octasaccharide a potential short-acting anticoagulant drug candidate that could reduce bleeding risk. Having access to a set of critically important 3-O-sulfated oligosaccharides offers the potential to develop new heparan sulfate-based therapeutics
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Using a 3-O-sulfated heparin Octasaccharide to inhibit the entry of herpes simplex virus type 1.
Biochemistry, 2008Co-Authors: Ronald J. Copeland, Arun Balasubramaniam, Vaibhav Tiwari, Fuming Zhang, Arlene S. Bridges, Robert J. Linhardt, Deepak Shukla, Jian LiuAbstract:Heparan sulfate (HS) is a highly sulfated polysaccharide and is present in large quantities on the cell surface and in the extracellular matrix. Herpes simplex virus type 1 (HSV-1) utilizes a specialized cell surface HS, known as 3-O-sulfated HS, as an entry receptor to establish infection. Here, we exploit an approach to inhibiting HSV-1 infection by using a 3-O-sulfated Octasaccharide, mimicking the active domain of the entry receptor. The 3-O-sulfated Octasaccharide was synthesized by incubating a heparin Octasaccharide (3-OH Octasaccharide) with HS 3-O-sulfotransferase isoform 3. The resultant 3-O-sulfated Octasaccharide has a structure of Delta UA2S-GlcNS6S-IdoUA2S-GlcNS6S-IdoUA2S-GlcNS3S6S-IdoUA2S-GlcNS6S (where Delta UA is 4-deoxy-alpha-L-threo-hex-4-enopyranosyluronic acid, GlcN is D-glucosamine, and IdoUA is L-iduronic acid). Results from cell-based assays revealed that the 3-O-sulfated Octasaccharide has stronger activity in blocking HSV-1 infection than that of the 3-OH Octasaccharide, suggesting that the inhibition of HSV-1 infection requires a unique sulfation moiety. Our results suggest the feasibility of inhibiting HSV-1 infection by blocking viral entry with a specific oligosaccharide.
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Characterization of a Heparan Sulfate Octasaccharide That Binds to Herpes Simplex Virus Type 1 Glycoprotein D
The Journal of biological chemistry, 2002Co-Authors: Jian Liu, Keiichi Yoshida, Ronald J. Copeland, Zach Shriver, R. Marshall Pope, Suzanne C. Thorp, Michael Duncan, Christina S. Raska, Roselyn J. Eisenberg, Gary H. CohenAbstract:Abstract Herpes simplex virus type 1 utilizes cell surface heparan sulfate as receptors to infect target cells. The unique heparan sulfate saccharide sequence offers the binding site for viral envelope proteins and plays critical roles in assisting viral infections. A specific 3-O-sulfated heparan sulfate is known to facilitate the entry of herpes simplex virus 1 into cells. The 3-O-sulfated heparan sulfate is generated by the heparan sulfate d-glucosaminyl-3-O-sulfotransferase isoform 3 (3-OST-3), and it provides binding sites for viral glycoprotein D (gD). Here, we report the purification and structural characterization of an oligosaccharide that binds to gD. The isolated gD-binding site is an Octasaccharide, and has a binding affinity to gD around 18 μm, as determined by affinity coelectrophoresis. The Octasaccharide was prepared and purified from a heparan sulfate oligosaccharide library that was modified by purified 3-OST-3 enzyme. The molecular mass of the isolated Octasaccharide was determined using both nanoelectrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry. The results from the sequence analysis suggest that the structure of the Octasaccharide is a heptasulfated Octasaccharide. The proposed structure of the Octasaccharide is ΔUA-GlcNS-IdoUA2S-GlcNAc-UA2S-GlcNS-IdoUA2S-GlcNH23S6S. Given that the binding of 3-O-sulfated heparan sulfate to gD can mediate viral entry, our results provide structural information about heparan sulfate-assisted viral entry.
Koji Kimata - One of the best experts on this subject based on the ideXlab platform.
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Specific Inhibition of FGF-2 Signaling with 2-O-sulfated Octasaccharides of Heparan Sulfate
Glycobiology, 2009Co-Authors: Satoko Ashikari-hada, Hiroko Habuchi, Noriko Sugaya, Takashi Kobayashi, Koji KimataAbstract:In fibroblast growth factor (FGF)-2 signaling, the formation of a ternary complex of FGF-2, tyrosine-kinase fibroblast growth factor receptor (FGFR)-1, and cell surface heparan sulfate (HS) proteoglycan is known to be critical for the activation of FGFR-1 and downstream signal transduction. Exogenous heparin polymer and some Octasaccharides inhibited FGF-2-induced phosphorylation both of FGFR-1 and of extracellular signal-regulated kinase (ERK1/2) in Chinese hamster ovary (CHO)-K1 cells transfected with FGFR-1, which present HS on their cell surface. The inhibitory effect of Octasaccharide was dependent on the number of 2-O-sulfate groups within a molecule but independent of the number of 6-O-sulfate groups. Sulfation at the 2-O-position was a prerequisite not only for the binding of HS to FGF-2 but also for regulation of FGF-2 signaling and competitive inhibition with endogenous HS. Interestingly, FGF-4-induced phosphorylation was impeded only by specific Octasaccharides containing both 2-O- and 6-O-sulfated groups, which were necessary for binding FGF-4. In CHO-677 cells deficient in HS biosynthesis, heparin enhanced FGF-2-induced phosphorylation of ERK1/2. On the other hand, an FGF-2-binding Octasaccharide inhibited the phosphorylation. Our data suggest that the activity of particular heparin-binding factors can be inhibited by distinctive oligosaccharides that can bind the factors but cannot form functional signaling complexes irrespective of whether cells have a normal complement of HS or lack HS.
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characterization of growth factor binding structures in heparin heparan sulfate using an Octasaccharide library
Journal of Biological Chemistry, 2004Co-Authors: Satoko Ashikarihada, Yutaka Kariya, Hiroko Habuchi, Nobuyuki Itoh, Hari A Reddi, Koji KimataAbstract:Abstract Heparan sulfate (HS) chains interact with various growth and differentiation factors and morphogens, and the most interactions occur on the specific regions of the chains with certain monosaccharide sequences and sulfation patterns. Here we generated a library of Octasaccharides by semienzymatic methods by using recombinant HS 2-O-sulfotransferase and HS 6-O-sulfotransferase, and we have made a systematic investigation of the specific binding structures for various heparin-binding growth factors. An Octasaccharide (Octa-I, ΔHexA-GlcNSO3-(HexA-GlcNSO3)3) was prepared by partial heparitinase digestion from completely desulfated N-resulfated heparin. 2-O- and 6-O-sulfated Octa-I were prepared by enzymatically transferring one to three 2-O-sulfate groups and one to three 6-O-sulfate groups per molecule, respectively, to Octa-I. Another Octasaccharide containing 3 units of HexA(2SO4)-GlcNSO3(6SO4) was prepared also from heparin. This Octasaccharide library was subjected to affinity chromatography for interactions with fibroblast growth factor (FGF)-2, -4, -7, -8, -10, and -18, hepatocyte growth factor, bone morphogenetic protein 6, and vascular endothelial growth factor, respectively. Based upon differences in the affinity to those Octasaccharides, the growth factors could be classified roughly into five groups: group 1 needed 2-O-sulfate but not 6-O-sulfate (FGF-2); group 2 needed 6-O-sulfate but not 2-O-sulfate (FGF-10); group 3 had the affinity to both 2-O-sulfate and 6-O-sulfate but preferred 2-O-sulfate (FGF-18, hepatocyte growth factor); group 4 required both 2-O-sulfate and 6-O-sulfate (FGF-4, FGF-7); and group 5 hardly bound to any Octasaccharides (FGF-8, bone morphogenetic protein 6, and vascular endothelial growth factor). The approach using the oligosaccharide library may be useful to define specific structures required for binding to various heparin-binding proteins. Octasaccharides with the high affinity to FGF-2 and FGF-10 had the activity to release them, respectively, from their complexes with HS. Thus, the library may provide new reagents to specifically regulate bindings of the growth factors to HS.
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characterization of growth factor binding structures in heparin heparan sulfate using an Octasaccharide library
Journal of Biological Chemistry, 2004Co-Authors: Satoko Ashikarihada, Yutaka Kariya, Hiroko Habuchi, Nobuyuki Itoh, Hari A Reddi, Koji KimataAbstract:Heparan sulfate (HS) chains interact with various growth and differentiation factors and morphogens, and the most interactions occur on the specific regions of the chains with certain monosaccharide sequences and sulfation patterns. Here we generated a library of Octasaccharides by semienzymatic methods by using recombinant HS 2-O-sulfotransferase and HS 6-O-sulfotransferase, and we have made a systematic investigation of the specific binding structures for various heparin-binding growth factors. An Octasaccharide (Octa-I, DeltaHexA-GlcNSO(3)-(HexA-GlcNSO(3))(3)) was prepared by partial heparitinase digestion from completely desulfated N-resulfated heparin. 2-O- and 6-O-sulfated Octa-I were prepared by enzymatically transferring one to three 2-O-sulfate groups and one to three 6-O-sulfate groups per molecule, respectively, to Octa-I. Another Octasaccharide containing 3 units of HexA(2SO(4))-GlcNSO(3)(6SO(4)) was prepared also from heparin. This Octasaccharide library was subjected to affinity chromatography for interactions with fibroblast growth factor (FGF)-2, -4, -7, -8, -10, and -18, hepatocyte growth factor, bone morphogenetic protein 6, and vascular endothelial growth factor, respectively. Based upon differences in the affinity to those Octasaccharides, the growth factors could be classified roughly into five groups: group 1 needed 2-O-sulfate but not 6-O-sulfate (FGF-2); group 2 needed 6-O-sulfate but not 2-O-sulfate (FGF-10); group 3 had the affinity to both 2-O-sulfate and 6-O-sulfate but preferred 2-O-sulfate (FGF-18, hepatocyte growth factor); group 4 required both 2-O-sulfate and 6-O-sulfate (FGF-4, FGF-7); and group 5 hardly bound to any Octasaccharides (FGF-8, bone morphogenetic protein 6, and vascular endothelial growth factor). The approach using the oligosaccharide library may be useful to define specific structures required for binding to various heparin-binding proteins. Octasaccharides with the high affinity to FGF-2 and FGF-10 had the activity to release them, respectively, from their complexes with HS. Thus, the library may provide new reagents to specifically regulate bindings of the growth factors to HS.
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Characterization of Growth Factor-binding Structures in Heparin/Heparan Sulfate Using an Octasaccharide Library
Journal of Biological Chemistry, 2004Co-Authors: Satoko Ashikari-hada, Yutaka Kariya, Hiroko Habuchi, Nobuyuki Itoh, A. Hari Reddi, Koji KimataAbstract:Heparan sulfate (HS) chains interact with various growth and differentiation factors and morphogens, and the most interactions occur on the specific regions of the chains with certain monosaccharide sequences and sulfation patterns. Here we generated a library of Octasaccharides by semienzymatic methods by using recombinant HS 2-O-sulfotransferase and HS 6-O-sulfotransferase, and we have made a systematic investigation of the specific binding structures for various heparin-binding growth factors. An Octasaccharide (Octa-I, DeltaHexA-GlcNSO(3)-(HexA-GlcNSO(3))(3)) was prepared by partial heparitinase digestion from completely desulfated N-resulfated heparin. 2-O- and 6-O-sulfated Octa-I were prepared by enzymatically transferring one to three 2-O-sulfate groups and one to three 6-O-sulfate groups per molecule, respectively, to Octa-I. Another Octasaccharide containing 3 units of HexA(2SO(4))-GlcNSO(3)(6SO(4)) was prepared also from heparin. This Octasaccharide library was subjected to affinity chromatography for interactions with fibroblast growth factor (FGF)-2, -4, -7, -8, -10, and -18, hepatocyte growth factor, bone morphogenetic protein 6, and vascular endothelial growth factor, respectively. Based upon differences in the affinity to those Octasaccharides, the growth factors could be classified roughly into five groups: group 1 needed 2-O-sulfate but not 6-O-sulfate (FGF-2); group 2 needed 6-O-sulfate but not 2-O-sulfate (FGF-10); group 3 had the affinity to both 2-O-sulfate and 6-O-sulfate but preferred 2-O-sulfate (FGF-18, hepatocyte growth factor); group 4 required both 2-O-sulfate and 6-O-sulfate (FGF-4, FGF-7); and group 5 hardly bound to any Octasaccharides (FGF-8, bone morphogenetic protein 6, and vascular endothelial growth factor). The approach using the oligosaccharide library may be useful to define specific structures required for binding to various heparin-binding proteins. Octasaccharides with the high affinity to FGF-2 and FGF-10 had the activity to release them, respectively, from their complexes with HS. Thus, the library may provide new reagents to specifically regulate bindings of the growth factors to HS.
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Oligosaccharide Library-based Assessment of Heparan Sulfate 6-O-Sulfotransferase Substrate Specificity
The Journal of biological chemistry, 2003Co-Authors: Per Jemth, Hiroko Habuchi, Koji Kimata, Emanuel Smeds, Ulf Lindahl, Marion Kusche-gullbergAbstract:Abstract Heparan sulfate mediates numerous complex biological processes. Its action critically depends on the amount and the positions of O-sulfate groups (iduronyl 2-O-sulfates, glucosaminyl 6-O- and 3-O-sulfates) that form binding sites for proteins. The structures and distribution of these protein-binding domains are influenced by the expression and substrate specificity of heparan sulfate biosynthetic enzymes. We describe a general approach to assess substrate specificities of enzymes involved in glycosaminoglycan metabolism, here applied to 6-O-sulfotransferases involved in heparan sulfate biosynthesis. To understand how 2-O-sulfation affects subsequent 6-O-sulfation reactions, the substrate specificity of 6-O-sulfotransferase 3 was probed using substrates from a heparin-based Octasaccharide library. Purified 3H-labeled N-sulfated Octasaccharides from a library designed to sample 2-O-sulfated motifs were used as sulfate acceptors, 3′-phosphoadenosine 5′-phosphosulfate as sulfate donor, and cell extract from 6-O-sulfotransferase 3-overexpressing 293 cells as enzyme source in the 6-O-sulfotransferase-catalyzed reactions. The first 6-O-sulfate group was preferentially incorporated at the internal glucosamine unit of the Octasaccharide substrate. As the reaction proceeded, the Octasaccharides acquired three 6-O-sulfate groups. The specificities toward competing Octasaccharide substrates, for 6-O-sulfotransferase 2 and 6-O-sulfotransferase 3, were determined using overexpressing 293 cell extracts and purified Octasaccharides. Both 6-O-sulfotransferases showed a preference for 2-O-sulfated substrates. The specificity toward substrates with two to three 2-O-sulfate groups was three to five times higher as compared with Octasaccharides with no or one 2-O-sulfate group.
Nikolay E. Nifantiev - One of the best experts on this subject based on the ideXlab platform.
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Influence of Modified Fucoidan and Related Sulfated Oligosaccharides on Hematopoiesis in Cyclophosphamide-Induced Mice
MDPI AG, 2018Co-Authors: Natalia Yu. Anisimova, Nadezhda E. Ustyuzhanina, Maria I. Bilan, Fedor V. Donenko, Natalia A. Ushakova, Anatolii I. Usov, Mikhail V. Kiselevskiy, Nikolay E. NifantievAbstract:Immunosuppression derived after cytostatics application in cancer chemotherapy is considered as an adverse side effect that leads to deterioration of quality of life and risk of infectious diseases. A linear sulfated (1→3)-α-l-fucan M-Fuc prepared by chemical modification of a fucoidan isolated from the brown seaweed Chordaria flagelliformis, along with two structurally related synthetic sulfated oligosaccharides, were studied as stimulators of hematopoiesis on a model of cyclophosphamide immunosuppression in mice. Recombinant granulocyte colony-stimulating factor (r G-CSF), which is currently applied in medicine to treat low blood neutrophils, was used as a reference. Polysaccharide M-Fuc and sulfated difucoside DS did not demonstrate significant effect, while sulfated Octasaccharide OS showed higher activity than r G-CSF, causing pronounced neutropoiesis stimulation. In addition, production of erythrocytes and platelets was enhanced after the Octasaccharide administration. The assessment of populations of cells in blood and bone marrow of mice revealed the difference in mechanisms of action of OS and r G-CSF
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Neoglycoconjugate of Tetrasaccharide Representing One Repeating Unit of the Streptococcus pneumoniae Type 14 Capsular Polysaccharide Induces the Production of Opsonizing IgG1 Antibodies and Possesses the Highest Protective Activity As Compared to Hex
Frontiers in immunology, 2017Co-Authors: Ekaterina A. Kurbatova, Nelli K. Akhmatova, Elina A. Akhmatova, Nadezhda B. Egorova, Natalya E. Yastrebova, Elena V. Sukhova, Dmitriy V. Yashunsky, Yury E. Tsvetkov, Marina L. Gening, Nikolay E. NifantievAbstract:Identifying protective synthetic oligosaccharide (OS) epitopes of Streptococcus pneumoniae capsular polysaccharides (CP) is an indispensable step in the development of third generation carbohydrate pneumococcal vaccines. Synthetic tetra-, hexa-, and Octasaccharide structurally related to CP of S. pneumoniae Type 14 were coupled to BSA, adjuvanted with aluminum hydroxide and tested for their immunogenicity in mice upon intraperitoneal prime-boost immunizations. Injections of the conjugates induced production of opsonizing anti-OS IgG1 antibodies. Immunization with the tetra- and Octasaccharide conjugates stimulated the highest titers of the specific antibodies. Further, the tetrasaccharide ligand demonstrated the highest ability to bind OS and CP antibodies. Murine immune sera developed against tetra- and Octasaccharide conjugates promoted pathogen opsonization to a higher degree than antisera against conjugated hexasaccharide. For the first time, the protective activities of these glycoconjugates were demonstrated in mouse model of generalized pneumococcal infections. The tetrasaccharide conjugate possessed the highest protective activities. Conversely, the Octasaccharide conjugate had lower protective activities and the lowest one showed the hexasaccharide conjugate. Sera against all of the glycoconjugates passively protected naive mice from pneumococcal infections. Given that the BSA-tetrasaccharide induced the most abundant yield of specific antibodies and the best protective activity, this OS may be regarded as the most promising candidate for the development of conjugated vaccines against S. pneumoniae type 14 infections.
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Neoglycoconjugate of Tetrasaccharide Representing One Repeating Unit of the Streptococcus pneumoniae Type 14 Capsular Polysaccharide Induces the Production of Opsonizing IgG1 Antibodies and Possesses the Highest Protective Activity As Compared to Hex
Frontiers Media S.A., 2017Co-Authors: Ekaterina A. Kurbatova, Nelli K. Akhmatova, Elina A. Akhmatova, Nadezhda B. Egorova, Natalya E. Yastrebova, Elena V. Sukhova, Dmitriy V. Yashunsky, Yury E. Tsvetkov, Marina L. Gening, Nikolay E. NifantievAbstract:Identifying protective synthetic oligosaccharide (OS) epitopes of Streptococcus pneumoniae capsular polysaccharides (CPs) is an indispensable step in the development of third-generation carbohydrate pneumococcal vaccines. Synthetic tetra-, hexa-, and Octasaccharide structurally related to CP of S. pneumoniae type 14 were coupled to bovine serum albumin (BSA), adjuvanted with aluminum hydroxide, and tested for their immunogenicity in mice upon intraperitoneal prime-boost immunizations. Injections of the conjugates induced production of opsonizing anti-OS IgG1 antibodies (Abs). Immunization with the tetra- and Octasaccharide conjugates stimulated the highest titers of the specific Abs. Further, the tetrasaccharide ligand demonstrated the highest ability to bind OS and CP Abs. Murine immune sera developed against tetra- and Octasaccharide conjugates promoted pathogen opsonization to a higher degree than antisera against conjugated hexasaccharide. For the first time, the protective activities of these glycoconjugates were demonstrated in mouse model of generalized pneumococcal infections. The tetrasaccharide conjugate possessed the highest protective activities. Conversely, the Octasaccharide conjugate had lower protective activities and the lowest one showed the hexasaccharide conjugate. Sera against all of the glycoconjugates passively protected naive mice from pneumococcal infections. Given that the BSA-tetrasaccharide induced the most abundant yield of specific Abs and the best protective activity, this OS may be regarded as the most promising candidate for the development of conjugated vaccines against S. pneumoniae type 14 infections
