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1.	Bugaytsova, Jeanna, et al. (författare) pH regulated H. pylori adherence : implications for persistent infection and disease Annan publikation (övrigt vetenskapligt/konstnärligt)abstract Helicobacter pylori’s BabA adhesin binds strongly to gastric mucosal ABH/Leb glycans on the stomach epithelium and overlying mucus, materials continuously shed into the acidic gastric lumen. Here we report that this binding is acid labile, acid inactivation is fully reversible; and acid lability profiles vary with BabA sequence and correlate with disease patterns. Isogenic H. pylori strains from the gastric antrum and more acidic corpus were identified that differed in acid lability of receptor binding and in sequence near BabA’s carbohydrate binding domain. We propose that reversible acid inactivation of receptor binding helps H. pylori avoid clearance by mucosal shedding, and that strain differences in acid lability affect tissue tropism and the spectrum of associated gastric diseases.
2.	Svedhem, Sofia, et al. (författare) Synthesis and self-assembly of globotriose derivatives : A model system for studies of carbohydrate-protein interactions 2002 Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 18:7, s. 2848-2858 Tidskriftsartikel (refereegranskat)abstract Self-assembled monolayers (SAMs) on gold exposing a-D-Galp-(1 ? 4)-ß-D-Galp-(1?4)-ß-D-Glcp (globotriose) are described. A synthetic pathway for the preparation of the bioactive carbohydrate globotriose coupled directly to bis(16-hydroxyhexadecanyl) disulfide ((HOC16H32S)2), as well as via tetra- or di(ethylene glycol) spacers, was developed. The SAMs were characterized by ellipsometry, contact angle goniometry, infrared reflection-absorption spectroscopy, and by their interactions with monoclonal antibodies. The ellipsometry measurements of mixed SAMs revealed thicknesses between 22 and 40 Å, depending on the ratio between carbohydrate and non-carbohydrate disulfides in the preparation solution. When the solution contained 10% or more of the carbohydrate adsorbate, the modified gold substrates displayed total wetting. Infrared reflection-absorption spectroscopy conferred well-ordered SAMs with a high degree of crystallinity. Furthermore, two monoclonal antibodies (IgM, MAHI 419 and IgG, MAHI 5) showed different affinity for mixed SAMs depending on the fraction and the structure of the carbohydrate component used (globotriose or globotriose tetra(ethylene glycol)), with the largest amount of protein bound for MAHI 419 at 1-10% of surface carbohydrate. These results demonstrate the usefulness of the SAM approach to explore molecular details such as the effect of a spacer or antigen distribution on antibody interactions at interfaces.
3.	Adrian Meredith, Jenny, 1971-, et al. (författare) Design and synthesis of novel P2 substituents in diol-based HIV protease inhibitors 2010 Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 45:1, s. 160-170 Tidskriftsartikel (refereegranskat)abstract The synthesis and SAR of HIV-1 protease inhibitors containing novel P2 structural elements are presented. The inhibitors were designed having hydrogen bond accepting P2 substituents to probe potential favorable interactions to Asp-29/Asp-30 of the HIV-1 protease backbone utilizing inhibitor 3 as a model template. Several inhibitors were synthesized from an L-Val methyl amide P2 motif by appending hydrogen bonding moieties from either the isopropyl side-chain or from the methyl amide portion. The most promising inhibitors 4a and 4e displayed K-i values of 1.0 nM and 0.7 nM respectively and EC50 values in the MT4 cell-based assay of 0.17 mu M and 0.33 mu M respectively, a slight loss in potency compared to lead inhibitor 3. These inhibitors were also tested against an HIV protease inhibitor resistant strain carrying the M461, V82F, and 184V mutations. Inhibitors 4a and 4e displayed a 3 and 4 fold change respectively compared with HIV wild type, whereas lead inhibitor 3 showed a higher 9 fold change. This study further demonstrate the chemical tractability of the approach where various P2 substituents can be introduced in just one chemical step from lactone 21 enabling facile modifications of the overall properties in this inhibitor class.
4.	Andersson, Claes-Henrik, et al. (författare) Reversible Non-Covalent Derivatisation of Carbon Nanotubes with Glycosides 2009 Ingår i: Soft Matter. - 1744-683X. ; 5:14, s. 2713-2716 Tidskriftsartikel (refereegranskat)abstract SWNTs and MWNTs have been non-covalently functionalized with glycosides in a reversible manner, and fluorescence titrations have been used to quantify the formed supramolecular assemblies which for SWNTs exhibits increased water solubility.
5.	Andersson, Claes-Henrik, et al. (författare) Reversible non-covalent derivatisation of carbon nanotubes with glycosides 2009 Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-683X .- 1744-6848. ; 5:14, s. 2713-2716 Tidskriftsartikel (refereegranskat)abstract SWNTs and MWNTs have been non-covalently functionalized with glycosides in a reversible manner, and fluorescence titrations have been used to quantify the formed supramolecular assemblies which for SWNTs exhibits increased water solubility.
6.	Andre, Sabine, et al. (författare) Glycocluster Design for Improved Avidity and Selectivity in Blocking Human Lectin/Plant Toxin Binding to Glycoproteins and Cells 2010 Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 7:6, s. 2270-2279 Tidskriftsartikel (refereegranskat)abstract Blocking lectin/toxin binding to human cells by suitable inhibitors can therapeutically protect them from harmful effects. Clustered design of ligand presentation holds the promise of affinity increase relative to the free sugar and inherent selectivity among lectin targets. Using first a solid-phase assay with a glycoprotein presenting N-glycans as lectin-reactive probe, we assessed the inhibitory potency of bi- to tetravalent clusters on a plant toxin and three human adhesion/growth-regulatory lectins. Enhanced avidity relative to the free sugar was detected together with lectin-type selectivity. These effects were confirmed on the level of cells in vitro, also for two leguminous lectins. The lack of toxicity in cell proliferation assays excluded concerns to further work on these compounds. The given cluster design and the strategic combination of the two assay systems of increasing biorelevance will thus be helpful to take the next steps in drug development, e.g. tailoring the sugar headgroup.
7.	Arewang, Carl Johan, et al. (författare) Synthesis of urine drug metabolites : glucuronic acid glycosides of phenol intermediates 2007 Ingår i: Carbohydrate Research. - : Elsevier BV. - 0008-6215 .- 1873-426X. ; 342:7, s. 970-974 Tidskriftsartikel (refereegranskat)abstract The investigation of drug metabolism requires substantial amount of metabolites. Isolation from urine is tedious, therefore, the material obtained by synthesis is preferred. Substantial amounts of three tentative drug metabolites, phenolic glucuronides, have been prepared using easily available glycosyl donors. The final products [3(2-N-methyl-N-isopropylaminoethoxy)phenyl] beta-D-glucopyranosiduronic acid, 4-amino-3,5-dimethylphenyl beta-D-glucopyranosiduronic acid and [2(S)-propanoyl-6-O-naphthyl] beta-D-glucopyranuronic acid are useful as, for example, reference material in metabolite investigations.
8.	Arewång, Carl Johan, et al. (författare) Synthesis of urine drug metabolites: glucuronic acid glycosides of phenol intermediates 2007 Ingår i: Carbohydrate Research. - 0008-6215. ; 342:7, s. 970-974 Tidskriftsartikel (refereegranskat)
9.	Aspholm-Hurtig, Marina, et al. (författare) Functional adaptation of BabA, the H. pylori ABO blood group antigen binding adhesin. 2004 Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 305:5683, s. 519-22 Tidskriftsartikel (refereegranskat)abstract Adherence by Helicobacter pylori increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens (generalists), whereas 60% of adherent South American Amerindian strains bind blood group O antigens best (specialists). This specialization coincides with the unique predominance of blood group O in these Amerindians. Strains differed about 1500-fold in binding affinities, and diversifying selection was evident in babA sequences. We propose that cycles of selection for increased and decreased bacterial adherence contribute to babA diversity and that these cycles have led to gradual replacement of generalist binding by specialist binding in blood group O-dominant human populations.
10.	Bernardi, Anna, et al. (författare) Multivalent glycoconjugates as anti-pathogenic agents 2013 Ingår i: Chemical Society Reviews. - : Royal Society of Chemistry (RSC). - 0306-0012 .- 1460-4744. ; 42:11, s. 4709-4727 Forskningsöversikt (refereegranskat)abstract Multivalency plays a major role in biological processes and particularly in the relationship between pathogenic microorganisms and their host that involves protein-glycan recognition. These interactions occur during the first steps of infection, for specific recognition between host and bacteria, but also at different stages of the immune response. The search for high-affinity ligands for studying such interactions involves the combination of carbohydrate head groups with different scaffolds and linkers generating multivalent glycocompounds with controlled spatial and topology parameters. By interfering with pathogen adhesion, such glycocompounds including glycopolymers, glycoclusters, glycodendrimers and glyconanoparticles have the potential to improve or replace antibiotic treatments that are now subverted by resistance. Multivalent glycoconjugates have also been used for stimulating the innate and adaptive immune systems, for example with carbohydrate-based vaccines. Bacteria present on their surfaces natural multivalent glycoconjugates such as lipopolysaccharides and S-layers that can also be exploited or targeted in anti-infectious strategies.
11.	Björklund, Catarina, 1981-, et al. (författare) Design and synthesis of potent and selective BACE-1 inhibitors 2010 Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society. - 0022-2623 .- 1520-4804. ; 53:4, s. 1458-1464 Tidskriftsartikel (refereegranskat)abstract Several highly potent BACE-1 protease inhibitors have been developed from an inhibitor series containing a novel hydroxyethylene (HE) core structure displaying aryloxymethyl or benzyloxymethyl P1 side chains and a methoxy P1’ side chain. The target molecules were readily synthesized from chiral carbohydrate starting materials, furnishing the inhibitor compounds in good overall yields. The inhibitors show both high BACE-1 potency and good selectivity against cathepsin D, where the most potent inhibitor furnish a BACE-1 IC50 value of 0.32 nM and displays > 3000 fold selectivity over cathepsin D.
12.	Boysen, Mike, et al. (författare) Ethyl 2-acetamido-4,6-di-O-benzyl-2,3-N,O-carbonyl-2-deoxy-1-thio-beta-D-glycopyranoside as a versatile GlcNAc donor. 2005 Ingår i: Chemical communications (Cambridge, England). - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; :24, s. 3044-6 Tidskriftsartikel (refereegranskat)abstract The title donor, ethyl 2-acetamido-4,6-di-O-benzyl-2,3-N,O-carbonyl-2-deoxy-1-thio-beta-D-glycopyranoside, is shown to be an excellent glycosyl donor giving immediate and efficient access to variant GlcNAc-containing oligosaccharides.
13.	Bugaytsova, Jeanna, et al. (författare) Acid Responsive Helicobacter pylori Adherence : Implications for Chronic Infection and Disease Annan publikation (övrigt vetenskapligt/konstnärligt)
14.	Buts, Lieven, et al. (författare) Impact of natural variation in bacterial F17G adhesins on crystallization behaviour. 2005 Ingår i: Acta crystallographica. Section D, Biological crystallography. - : International Union of Crystallography (IUCr). - 0907-4449. ; 61:8, s. 1149-1159 Tidskriftsartikel (refereegranskat)abstract Since the introduction of structural genomics, the protein has been recognized as the most important variable in crystallization. Recent strategies to modify a protein to improve crystal quality have included rationally engineered point mutations, truncations, deletions and fusions. Five naturally occurring variants, differing in 1-18 amino acids, of the 177-residue lectin domain of the F17G fimbrial adhesin were expressed and purified in identical ways. For four out of the five variants crystals were obtained, mostly in non-isomorphous space groups, with diffraction limits ranging between 2.4 and 1.1 A resolution. A comparative analysis of the crystal-packing contacts revealed that the variable amino acids are often involved in lattice contacts and a single amino-acid substitution can suffice to radically change crystal packing. A statistical approach proved reliable to estimate the compatibilities of the variant sequences with the observed crystal forms. In conclusion, natural variation, universally present within prokaryotic species, is a valuable genetic resource that can be favourably employed to enhance the crystallization success rate with considerably less effort than other strategies.
15.	Carlsson, Magnus, et al. (författare) D-gluco-Hexodialdose in Aqueous Solution : Determination of the Main Forms by NMR spectroscopy Annan publikation (övrigt vetenskapligt/konstnärligt)
16.	Cioci, Gianluca, et al. (författare) Beta-propeller crystal structure of Psathyrella velutina lectin: an integrin-like fungal protein interacting with monosaccharides and calcium. 2006 Ingår i: Journal of molecular biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 357:5, s. 1575-91 Tidskriftsartikel (refereegranskat)abstract The lectin from the mushroom Psathyrella velutina recognises specifically N-acetylglucosamine and N-acetylneuraminic acid containing glycans. The crystal structure of the 401 amino acid residue lectin shows that it adopts a very regular seven-bladed beta-propeller fold with the N-terminal region tucked into the central cavity around the pseudo 7-fold axis. In the complex with N-acetylglucosamine, six monosaccharides are bound in pockets located between two consecutive propeller blades. Due to the repeats shown by the sequence the binding sites are very similar. Five hydrogen bonds between the protein and the sugar hydroxyl and N-acetyl groups stabilize the complex, together with the hydrophobic interactions with a conserved tyrosine and histidine. The complex with N-acetylneuraminic acid shows molecular mimicry with the same hydrogen bond network, but with different orientations of the carbohydrate ring in the binding site. The beta-hairpin loops connecting the two inner beta-strands of each blade are metal binding sites and two to three calcium ions were located in the structure. The multispecificity and high multivalency of this mushroom lectin, combined with its similarity to the extracellular domain of an important class of cell adhesion molecules, integrins, are another example of the outstanding success of beta-propeller structures as molecular binding machines in nature.
17.	Covarrubias, Adrian Suarez, et al. (författare) Structural, biochemical and in vivo investigations of the threonine synthase from Mycobacterium tuberculosis 2008 Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 381:3, s. 622-633 Tidskriftsartikel (refereegranskat)abstract Threonine biosynthesis is a general feature of prokaryotes, eukaryotic microorganisms, and higher plants. Since mammals lack the appropriate synthetic machinery, instead obtaining the amino acid through their diet, the pathway is a potential focus for the development of novel antibiotics, antifungal agents, and herbicides. Threonine synthase (TS), a pyridoxal-5-phosphate-dependent enzyme, catalyzes the final step in the pathway, in which L-homoserine phosphate and water are converted into threonine and inorganic phosphate. In the present publication, we report structural and functional studies of Mycobacterium tuberculosis TS, the product of the rv1295 (thrC) gene. The structure gives new insights into the catalytic mechanism of TSs in general, specifically by suggesting the direct involvement of the phosphate moiety of the cofactor, rather than the inorganic phosphate product, in transferring a proton from C4' to C-gamma in the formation of the alpha beta-unsaturated aldimine. It further provides a basis for understanding why this enzyme has a higher pH optimum than has been reported elsewhere for TSs and gives rise to the prediction that the equivalent enzyme from Thermus thermophilus will exhibit similar behavior. A deletion of the relevant gene generated a strain of M. tuberculosis that requires threonine for growth, such auxotrophic strains are frequently attenuated in vivo, indicating that TS is a potential drug target in this organism.
18.	Fourniere, Viviane, et al. (författare) Synthesis of the Lewis b pentasaccharide and a HSA-conjugate thereof 2010 Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 66:39, s. 7850-7855 Tidskriftsartikel (refereegranskat)abstract Helicobacter pylori, a gastric pathogen, binds to various blood group antigens, including the Lewis types, present in the gastric tissue and a relation between the presentation of the ligands and the overall strength of binding has been assumed. Synthetic Lewis b tetra- and hexasaccharide conjugates are available but not the analogous pentasaccharide. An efficient synthesis of the amino spacer equipped Lewis b pentasaccharide, 3-aminopropyl alpha-L-fucopyranosyl-(1 -> 2)-beta-D-galactopyranosyl-(1 3)-[alpha-L-fucopyranosyl-(1 -> 4)]-2-acetamido-2-deoxy-beta-D-glucopyranosyl-(1 -> 3)-beta-D-galactopyranoside, is presented to enable further investigation of the carbohydrate recognition process of H. pylori.
19.	Gemma, Emiliano, et al. (författare) Synthesis of monodeoxy analogues of the trisaccharide alpha-D-Glcp-(1-->3)-alpha-D-Manp-(1-->2)-alpha-D-ManpOMe recognised by Calreticulin/Calnexin. 2006 Ingår i: Carbohydrate research. - : Elsevier BV. - 0008-6215 .- 1873-426X. ; 341:10, s. 1533-42 Tidskriftsartikel (refereegranskat)abstract Six (3,4,4',6',3'' or 6'')-monodeoxy analogues of the title trisaccharide (1-6) have been prepared utilising monodeoxy monosaccharide precursors. The reducing end deoxy derivatives were synthesised by N-iodosuccinimide/silver trifluoromethanesulfonate (NIS/AgOTf)-promoted couplings of a common disaccharide thioglycoside donor 10 to suitably protected monodeoxy acceptors 9 and 12, affording trisaccharides, which after deprotection yielded target structures 1 and 2. The non-reducing end deoxy derivatives could similarly be produced by halide-assisted glycosylations of a common disaccharide acceptor 17 with monodeoxy glycosyl bromide donors (obtained from thioglycosides 18 and 20) to yield, after removal of protecting groups, target trisaccharides 3 and 4. The analogues with the deoxy function in the middle mannose residue, were obtained through orthogonal halide-assisted coupling of tetrabenzyl-glucopyranosyl bromide to monodeoxy thioglycoside acceptors to give thioglycoside disaccharides, which subsequently were used as donors in NIS/AgOTf-promoted couplings to a common 2-hydroxy-mannose acceptor 15 to afford trisaccharides; deprotection yielded the final target compounds 5 and 6.
20.	Gemma, Emiliano, et al. (författare) Synthesis of monodeoxy analogues of the trisaccharide α-D-Glcp-(1→3)-α-D-Manp-(1→2)-α-D-Manp Annan publikation (övrigt vetenskapligt/konstnärligt)
21.	Gemma, Emiliano, 1975- (författare) Synthesis of Oligosaccharides for Interaction Studies with Various Lectins 2005 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract In this thesis, the syntheses of oligosaccharides for interaction studies with various lectins are described. The first section reports the syntheses of tetra, tri- and disaccharides corresponding to truncated versions of the glucosylated arm of Glc1Man9(GlcNAc)2, found in the biosynthesis of N-glycans. The thermodynamic parameters of their interaction with calreticulin, a lectin assisting and promoting the correct folding of newly synthesised glycoproteins, were established by isothermal titration calorimetry. In the second section, a new synthetic pathway leading to the same tetra- and trisaccharides is discussed. Adoption of a convergent strategy and of a different protecting group pattern resulted in significantly increased yields of the target structures. The third section describes the syntheses of a number of monodeoxy-trisaccharides related to the above trisaccharide Glc-α-(1→3)-Man-α-(1→2)-Man-α-OMe. Differentsynthetic approaches were explored and the choice of early introduction of the deoxy functionality proved the most beneficial. In the last section, the synthesis of spacer-linked LacNAc dimers as substrates for the lectins galectin-1 and -3 is presented. This synthesis was realized by glycosidation of a number diols with peracetylated LacNAc-oxazoline. Pyridinium triflate was tested as a new promoter, affording the target dimers in high yields. This promoter in combination with microwave irradiation gave even higher yields and also shortened the reaction times.
22.	Gemma, Emiliano, et al. (författare) Synthesis of the tetrasaccharide alpha-D-Glcp-(1-->3)-alpha-D-Manp-(1-->2)-alpha-D-Manp-(1-->2)-alpha-D-Manp recognized by calreticulin/calnexin. 2005 Ingår i: Carbohydrate research. - : Elsevier BV. - 0008-6215. ; 340:16, s. 2558-62 Tidskriftsartikel (refereegranskat)abstract The title compound as its methyl glycoside was efficiently synthesized using a block synthesis approach. Halide-assisted glycosidations between 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl iodide and ethyl 2-O-acetyl-4,6-di-O-benzyl-1-thio-alpha-D-mannopyranoside using triphenylphosphine oxide as promoter yielded, with complete alpha-selectivity, a disaccharide building block in high yield. The perbenzylated derivative of this proved to be an excellent donor affording 88% of the protected target tetrasaccharide in an NIS/AgOTf-promoted coupling to a known methyl dimannoside acceptor. Deprotection through catalytic hydrogenolysis then gave the target compound in 47% overall yield.
23.	Gemma, Emiliano, et al. (författare) Synthesis of the tetrasaccharide α-D-Glcp-(1→3)-α-D-Manp-(1→2)-α-D-Manp-(1→2)-α-D-Manp recognised by Calreticulin/Calnexin 2005 Ingår i: Carbohydrate Research. - : Elsevier Ltd. - 0008-6215 .- 1873-426X. ; 340:16, s. 2558-2562 Tidskriftsartikel (refereegranskat)abstract The title compound as its methyl glycoside was efficiently synthesized using a block synthesis approach. Halide-assisted glycosidations between 6-O-acetyl-2,3,4-tri-O-benzyl-α-d-glucopyranosyl iodide and ethyl 2-O-acetyl-4,6-di-O-benzyl-1-thio-α-d-mannopyranoside using triphenylphosphine oxide as promoter yielded, with complete α-selectivity, a disaccharide building block in high yield. The perbenzylated derivative of this proved to be an excellent donor affording 88% of the protected target tetrasaccharide in an NIS/AgOTf-promoted coupling to a known methyl dimannoside acceptor. Deprotection through catalytic hydrogenolysis then gave the target compound in 47% overall yield.
24.	Gupta, Garima, et al. (författare) Defining substrate interactions with calreticulin: an isothermal titration calorimetric study 2008 Ingår i: Glycoconjugate Journal. - : Springer Science and Business Media LLC. - 0282-0080 .- 1573-4986. ; 25:8, s. 797-802 Tidskriftsartikel (refereegranskat)
25.	Hagner-McWhirter, Asa, et al. (författare) Irreversible glucuronyl C5-epimerization in the biosynthesis of heparan sulfate. 2004 Ingår i: J Biol Chem. - 0021-9258. ; 279:15, s. 14631-8 Tidskriftsartikel (refereegranskat)
26.	Hakkarainen, Birgit, et al. (författare) NMR study of hydroxy protons of di- and trimannosides, substructures of Man-9 2007 Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 45:12, s. 1076-1080 Tidskriftsartikel (refereegranskat)abstract The chemical shifts, temperature coefficients and inter-residual rotating-frame Overhauser effect (ROE)s for the hydroxy protons of some alpha-(1,2)-, alpha-(1,3)- and alpha-(1,6)linked di- and trimannosides have been measured for samples in 85% H2O/15% acetone-d(6) solution. These mannosides, Man alpha(1 -> 2)Man alpha OMe (1) Man alpha(1 -> 3)Man alpha OMe (2), Man alpha(1 -> 6)Man alpha OMe (3), Man alpha(1 -> 2)Man alpha(1 -> 2)Man alpha OMe (4), Man alpha(1 -> 2)Man alpha(1 -> 3)Man alpha OMe (5), Man alpha(1 -> 2)Man alpha(1 -> 6)Man alpha OMe (6) and Man alpha(1 -> 3)[Man alpha 1 -> 6]Man alpha OMe (7), are substructures of the N-glycan Man-9. The NMR data show that the hydration of each individual hydroxyl group in the di- and trisaccharides is very similar to the hydration of the corresponding hydroxyl in the monomeric methyl alpha-D-mannoside. No hydrogen-bond interactions were found to stabilize the conformations of the alpha-(1,2)- and alpha-(1,6)-linkages and the chemical shifts for the hydroxy proton resonances of the alpha-(1,6)-linkage indicated high-conformational flexibility. For the alpha-(1,3)-linkage, however, the downfield shift for the signal of O(2)H of the 3-substituted residue together with the ROE between this proton and H5' on the next residue suggest some weak inter-residue interactions.
27.	Hakkarainen, Birgit, et al. (författare) Spectral assignments and reference data : NMR study of hydroxy protons of di- and trimannosides, substructures of Man-9 2007 Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 45:12, s. 1076-1080 Tidskriftsartikel (refereegranskat)
28.	Ippel, Hans, et al. (författare) Intra- and inter-molecular interactions of human galectin-3: assessment by full-assignment-based NMR. 2016 Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 26:8, s. 888-903 Tidskriftsartikel (refereegranskat)abstract Galectin-3 is an adhesion/growth-regulatory protein with a modular design comprising an N-terminal tail (NT, residues 1-111) and the conserved carbohydrate recognition domain (CRD, residues 112-250). The chimera-type galectin interacts with both glycan and peptide motifs. Complete (13)C/(15)N-assignment of the human protein makes NMR-based analysis of its structure beyond the CRD possible. Using two synthetic NT polypeptides covering residues 1-50 and 51-107, evidence for transient secondary structure was found with helical conformation from residues 5 to 15 as well as proline-mediated, multi-turn structure from residues 18 to 32 and around PGAYP repeats. Intramolecular interactions occur between the CRD F-face (the 5-stranded β-sheet behind the canonical carbohydrate-binding 6-stranded β-sheet of the S-face) and NT in full-length galectin-3, with the sequence P(23)GAW(26) … P(37)GASYPGAY(45) defining the primary binding epitope within the NT. Work with designed peptides indicates that the PGAX motif is crucial for self-interactions between NT/CRD. Phosphorylation at position Ser6 (and Ser12) (a physiological modification) and the influence of ligand binding have minimal effect on this interaction. Lastly, galectin-3 molecules can interact weakly with each other via the F-faces of their CRDs, an interaction that appears to be assisted by their NTs. Overall, our results add insight to defining binding sites on galectin-3 beyond the canonical contact area for β-galactosides.
29.	Johansson, Susanne, 1977- (författare) Design and Synthesis of Sialic Acid Conjugates as Inhibitors of EKC-causing Adenoviruses 2008 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract The combat against viral diseases has been, and still is, a major challenge in the field of drug development. Viruses are intracellular parasites that use the host cell ma-chinery for their replication and release. Therefore it is difficult to target and destroy the viral particle without disturbing the essential functions of the host cell. This thesis describes studies towards antiviral agents targeting adenovirus type 37 (Ad37), which causes the severe ocular infection epidemic keratoconjunctivitis (EKC). Cell surface oligosaccharides serve as cellular receptors for many pathogens, including viruses and bacteria. For EKC-causing adenoviruses, cell surface oligo-saccharides with terminal sialic acid have recently been shown to be critical for their attachment to and infection of host cells. The work in this thesis support these re-sults and identifies the minimal binding epitope for viral recognition. As carbo-hydrate–protein interactions in general, the sialic acid–Ad37 interaction is very weak. Nature overcomes this problem and vastly improves the binding affinity by presenting the carbohydrates in a multivalent fashion. Adenoviruses interact with their cellular receptors via multiple fiber proteins, whereby it is likely that the ideal inhibitor of adenoviral infections should be multivalent. This thesis includes design and synthesis of multivalent sialic acid glycoconjugates that mimic the structure of the cellular receptor in order to inhibit adenoviral attachment to and infection of human corneal epithelial (HCE) cells. Synthetic routes to three different classes of sialic acid conjugates, i.e. derivatives of sialic acid, 3’-sialyllactose and N-acyl modified sialic acids, and their multivalent counterparts on human serum albumine (HSA) have been developed. Evaluation of these conjugates in cell binding and cell infectivity assays revealed that they are effective as inhibitors. Moreover the results verify the hypothesis of the multivalency effect and clearly shows that the power of inhibition is significantly increased with higher orders of valency. Potential inhibi-tors could easily be transferred to the eye using a salve or eye drops, and thereby they would escape the metabolic processes of the body, a major drawback of using carbohydrates as drugs. The results herein could therefore be useful in efforts to develop an antiviral drug for treatment of EKC.
30.	Kapoor, Mili, et al. (författare) Interactions of Substrate with Calreticulin, an Endoplasmic Reticulum Chaperone 2003 Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 278:8, s. 6194–6200- Tidskriftsartikel (refereegranskat)
31.	Karlsson, Erik (författare) Catalytic Oxidation Methods. Use of inexpensive and environmentally friendly Oxidants in organic Synthesis. 2009 Licentiatavhandling (övrigt vetenskapligt/konstnärligt)
32.	Kostlánová, Nikola, et al. (författare) The fucose-binding lectin from Ralstonia solanacearum. A new type of beta-propeller architecture formed by oligomerization and interacting with fucoside, fucosyllactose, and plant xyloglucan. 2005 Ingår i: The Journal of biological chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 280:30, s. 27839-49 Tidskriftsartikel (refereegranskat)abstract Plant pathogens, like animal ones, use protein-carbohydrate interactions in their strategy for host recognition, attachment, and invasion. The bacterium Ralstonia solanacearum, which is distributed worldwide and causes lethal wilt in many agricultural crops, was shown to produce a potent L-fucose-binding lectin, R. solanacearum lectin, a small protein of 90 amino acids with a tandem repeat in its amino acid sequence. In the present study, surface plasmon resonance experiments conducted on a series of oligosaccharides show a preference for binding to alphaFuc1-2Gal and alphaFuc1-6Gal epitopes. Titration microcalorimetry demonstrates the presence of two binding sites per monomer and an unusually high affinity of the lectin for alphaFuc1-2Gal-containing oligosaccharides (KD = 2.5 x 10(-7) M for 2-fucosyllactose). R. solanacearum lectin has been crystallized with a methyl derivative of fucose and with the highest affinity ligand, 2-fucosyllactose. X-ray crystal structures, the one with alpha-methyl-fucoside being at ultrahigh resolution, reveal that each monomer consists of two small four-stranded anti-parallel beta-sheets. Trimerization through a 3-fold or pseudo-3-fold axis generates a six-bladed beta-propeller architecture, very similar to that previously described for the fungal lectin of Aleuria aurantia. This is the first report of a beta-propeller formed by oligomerization and not by sequential domains. Each monomer presents two fucose binding sites, resulting in six symmetrically arranged sugar binding sites for the beta-propeller. Crystals were also obtained for a mutated lectin complexed with a fragment of xyloglucan, a fucosylated polysaccharide from the primary cell wall of plants, which may be the biological target of the lectin.
33.	Lahmann, Martina, 1963, et al. (författare) Synthesis of the Lewis b hexasaccharide and HSA-conjugates thereof. 2004 Ingår i: Glycoconjugate journal. - 0282-0080 .- 1573-4986. ; 21:5, s. 251-6 Tidskriftsartikel (refereegranskat)abstract An efficient and short route has been elaborated for the aminopropyl spacer equipped Leb hexasaccharide. For the preparation of HSA-conjugates of this oligosaccharide, the use of disuccinimidyl suberate (DSS) and disuccinimidyl glutarate (DSG) as cross-linker reagents has been evaluated. This conjugation method emerged as being faster and easier to monitor by standard MALDI-TOF spectrometry than squarate ester based conjugations of similar efficiency if DSS is used as cross-linker.
34.	Lahmann, Martina, 1963, et al. (författare) Synthesis of urine drug metabolites: Glucuronosyl esters of carboxymefloquine, indoprofen, (S)-naproxen, and desmethyl (S)-naproxen 2004 Ingår i: Journal of Carbohydrate Chemistry. - : Taylor & Francis Group. - 0732-8303 .- 1532-2327. ; 23:2-3, s. 123-132 Tidskriftsartikel (refereegranskat)abstract A general procedure for the synthesis of 1-O-acyl-beta-D-glucuronic acids using the benzyl 1-O-trichloroacetimidoyl-2,3,4-tri-O-benzyl-D-glucopyranuronate 6 as donor is exemplified by the synthesis of the urine metabolites of (S)-naproxen, desmethyl (S)-naproxen, indoprofen, and carboxymefloquine. The key intermediate benzyl 2,3,4-tri-O-benzyl-D-glucopyranuronate 5 is easily accessible in four steps (29%) from the peracetylated beta-D-glucuronic acid 1.
35.	Long, Mark, et al. (författare) Synthesis of type 1 Lewis b hexasaccharide antigen structures featuring flexible incorporation ofl-[U-C-13(6)]-fucose for NMR binding studies 2020 Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 18:23, s. 4452-4458 Tidskriftsartikel (refereegranskat)abstract While(13)C-labelled proteins are common tools in NMR studies, lack of access to(13)C-labelled carbohydrate structures has restricted their use.l-Fucose is involved in a wide range of physiological and pathophysiological processes in mammalian organisms. Here,l-[U-C-13(6)]-Fuc labelled type I Lewis b (Le(b)) structures have been synthesised for use in NMR binding studies with the Blood-group Antigen Binding Adhesin (BabA), a membrane-bound protein from the bacteriumHelicobacter pylori. As part of this work, an efficient synthesis of a benzylatedl-[U-C-13(6)]-Fuc thioglycoside donor froml-[U-C-13(6)]-Gal has been developed. The design and synthesis of an orthogonally protected tetrasaccharide precursor enabled controlled introduction of one or two(13)C-labelled or non-labelled fucosyl residues prior to global deprotection. NMR analysis showed that it is straightforward to assign the anomeric centres as well as the H-5 positions to the individual fucosyl residues which are relevant for NMR binding studies.
36.	Mannerstedt, Karin, et al. (författare) Evaluation of Thioglycosides of Kdo as Glycosyl Donor 2007 Ingår i: Carbohydrate Research. - : Elsevier. - 0008-6215 .- 1873-426X. ; 342:3-4, s. 631-637 Tidskriftsartikel (refereegranskat)abstract The use of Kdo thioglycosides as glycosyl donors using DMTST, IBr/AgOTf and NIS/AgOTf as promoters has been evaluated. Activation at low temperature allowed to escape the formation of 2,3-glycal byproducts to give glycosides in high yield and with good β-anomeric selectivity. The use of diethyl ether as solvent and (especially) isopropylidene acetals as protecting groups improved the α-anomeric selectivity. NIS/AgOTf as promoter surprisingly yielded the 3-iodo-product via the glycal intermediate.
37.	Mannerstedt, Karin, et al. (författare) Evaluation of thioglycosides of Kdo as glycosyl donors 2007 Ingår i: Carbohydrate Research. - 0008-6215. ; 342:3-4, s. 631-637 Tidskriftsartikel (refereegranskat)
38.	Mannerstedt, Karin, et al. (författare) Synthesis of a common tetrasaccharide motif of Haemophilus influenzae LPS inner core structures 2008 Ingår i: Organic & Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 6:6, s. 1087-1091 Tidskriftsartikel (refereegranskat)
39.	Mannerstedt, Karin, et al. (författare) Synthesis of glycero-α-D-manno-heptopyranosyl-(1→2)-(6-O-aminoethylphosphono-L-glycero-α-D-manno-heptopyranosyl)-(1→3)-[β-D-glucopyranosyl-(1→4)]-L-glycero-α-D-manno-heptopyranose : A common tetrasaccharide motif of Haemophilus influenzae LPS inner core structures Ingår i: Organic & Biomolecular Chemistry. Tidskriftsartikel (refereegranskat)
40.	Mannerstedt, Karin, 1975- (författare) Synthesis of Oligosaccharides from the Inner Core Structure of Haemophilus Influenzae and Neisseria meningitidis Lipopolysaccharides 2006 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract This thesis describes the synthesis of oligosaccharides corresponding to different parts of the lipopolysaccharide (LPS) inner core structure from Haemophilus influenzae and Neisseria meningitidis. Chapter 2 describes the synthesis of a protected trisaccharide common to H. influenzae and N. meningitidis LPS, which can be used as a versatile precursor in further syntheses of larger LPS structures. In Chapter 3 syntheses towards phosphoethanolamine substituted trisaccharides corresponding to H. influenzae and N. meningitidis structures are presented. In Chapter 4 the synthesis of a H. influenzae tetrasaccharide structure, with and without a phosphoethanolamine substituent in the 6-position of the second heptose unit, is described. Conjugation to biotin of these two tetrasaccharides is also performed. Chapter 5 describes the synthesis of a spacer-equipped Kdo acceptor that is subsequently attached to the tetrasaccharide described in Chapter 4 forming a pentasaccharide from the inner core structure of H. influenzae. Similar to the synthesis of the tetrasaccharide, a phosphoethanolamine is attached to the 6 position of the second heptose. Chapter 5 also describes the synthesis of various Kdo thioglycoside donors and their evaluation in glycosylation reactions using different promoters and reaction conditions.
41.	Mannerstedt, Karin, et al. (författare) Synthesis of Phosphoethanolamine-substituted Trisaccharides Corresponding to Neisseria meningitidis and Haemophilus influenzae LPS Structures Annan publikation (övrigt vetenskapligt/konstnärligt)
42.	Mannerstedt, Karin, et al. (författare) Synthesis ofHaemophilus influenzae LPS Annan publikation (övrigt vetenskapligt/konstnärligt)
43.	Mohan, Halasayam, et al. (författare) Efficient Synthesis of Spacer-linked Dimers of N-Acetyllactosamine Using Microvawe-assisted Pyridinium Triflate-promoted Glycosylations with Oxazoline Donors 2003 Ingår i: Synlett. - : Georg Thieme Verlag KG. - 0936-5214 .- 1437-2096. ; :9, s. 1255-1256 Tidskriftsartikel (refereegranskat)
44.	Monica, Ek, et al. (författare) Reductive Ring Openings of Carbohydrate Benzylidene Acetals Using Borane-Trimethylamine and Aluminium Chloride. Regioselectivity and Solvent Dependance 1983 Ingår i: Journal of carbohydrate chemistry. - 0732-8303 .- 1532-2327. ; 2:3, s. 305-311 Tidskriftsartikel (refereegranskat)abstract Regioselective reductive ring openings of 4, 6-O-benzylidene acetals of hexopyranosides are described using borane trimethylamine-aluminium chloride. Using toluene as solvent, 4-O-benzyl ethers with the 6-OH free are obtained. Using tetrahydrofuran as solvent. 6-O-benzyl ethers with the 4-OH free are obtained.
45.	Moonens, Kristof, et al. (författare) Structural Insights into Polymorphic ABO Glycan Binding by Helicobacter pylori 2016 Ingår i: Cell Host and Microbe. - : Elsevier BV. - 1931-3128 .- 1934-6069. ; 19:1, s. 55-66 Tidskriftsartikel (refereegranskat)abstract The Helicobacter pylori adhesin BabA binds mucosal ABO/Le b blood group (bg) carbohydrates. BabA facilitates bacterial attachment to gastric surfaces, increasing strain virulence and forming a recognized risk factor for peptic ulcers and gastric cancer. High sequence variation causes BabA functional diversity, but the underlying structural-molecular determinants are unknown. We generated X-ray structures of representative BabA isoforms that reveal a polymorphic, three-pronged Le(b) binding site. Two diversity loops, DL1 and DL2, provide adaptive control to binding affinity, notably ABO versus O bg preference. H. pylori strains can switch bg preference with single DL1 amino acid substitutions, and can coexpress functionally divergent BabA isoforms. The anchor point for receptor binding is the embrace of an ABO fucose residue by a disulfide-clasped loop, which is inactivated by reduction. Treatment with the redox-active pharmaceutic N-acetylcysteine lowers gastric mucosal neutrophil infiltration in H. pylori-infected Le(b)-expressing mice, providing perspectives on possible H. pylori eradication therapies.
46.	Nestor, Gustav, et al. (författare) A detailed picture of a protein-carbohydrate hydrogen-bonding network revealed by NMR and MD simulations 2021 Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 31:4, s. 508-518 Tidskriftsartikel (refereegranskat)abstract Cyanovirin-N (CV-N) is a cyanobacterial lectin with antiviral activity towards HIV and several other viruses. Here, we identify mannoside hydroxyl protons that are hydrogen bonded to the protein backbone of the CV-N domain B binding site, using NMR spectroscopy. For the two carbohydrate ligands Manα(1→2)ManαOMe and Manα(1→2) Manα(1→6)ManαOMe five hydroxyl protons are involved in hydrogen-bonding networks. Comparison with previous crystallographic results revealed that four of these hydroxyl protons donate hydrogen bonds to protein backbone carbonyl oxygens in solution and in the crystal. Hydrogen bonds were not detected between the side chains of Glu41 and Arg76 with sugar hydroxyls, as previously proposed for CV-N binding of mannosides. Molecular dynamics simulations of the CV-N/Manα(1→2)Manα(1→6)ManαOMe complex confirmed the NMR-determined hydrogen-bonding network. Detailed characterization of CV-N/mannoside complexes provides a better understanding of lectin-carbohydrate interactions and opens up to the use of CV-N and similar lectins as antiviral agents.
47.	Nkambule, Comfort M., et al. (författare) Efficient regioselective protection of myo-inositol via migration facile protecting group 2011 Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 67:3, s. 618-623 Tidskriftsartikel (refereegranskat)abstract A cis-1,2-cyclohexanediol, 1,4,5,6-tetra-O-benzyl-myo-inositol, was selectively protected at the axial C2-hydroxyl via acid-mediated rearrangement of the corresponding 1,2-orthoacetate, or via the base-induced migration of a protecting group that had previously been easily installed with complete regioselectivity at the adjacent equatorial hydroxyl. Esters 4a-6a were synthesized in high yields (75-82%) while sulfonate 7a and silyl ether 8a were obtained in 85 and 31% yields, respectively. The migration of the esters induced by DBU results in equilibrium between regioisomers favouring the C2 protected isomer, but NaH induced migration of sulfonyl and silyl groups results in complete migration from equatorial to axial hydroxyl groups.
48.	Olsson, Johan D. M., et al. (författare) Investigations of glycosylation reactions with 2-N-acetyl-2N,3O-oxazolidinone-protected glucosamine donors 2008 Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 73:18, s. 7181-7188 Tidskriftsartikel (refereegranskat)abstract NIS/AgOTf-promoted glycosylations with ethyl 2,3-N,O-carbonyl-2-deoxy-1-thio-beta-D-glueopyranoside donors can be performed with either alpha- or beta-selectivity by tuning the reaction conditions. Small amounts of AgOTf (0.1 equiv) and short reaction times give beta-selectivity, whereas 0.4 equiv of AgOTf and prolonged reaction times afford alpha-linked products. NMR-monitored glycosylation and anomerization experiments show initial formation of exclusively the beta-linkage, which anomerizes, through an intramolecular mechanism involving an endocyclic C - O bond cleavage, to the alpha-linkage.
49.	Olsson, Johan D M, et al. (författare) Synthesis of and molecular dynamics simulations on a tetrasaccharide corresponding to the repeating unit of the capsular polysaccharide from Salmonella enteritidis 2009 Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 7:8, s. 1612-1618 Tidskriftsartikel (refereegranskat)
50.	Olsson, Johan D.M., et al. (författare) Synthesis of phosphorylated 3,4-branched trisaccharides corresponding to LPS inner core structures of Neisseria meningitidis and Haemophilus influenzae 2010 Ingår i: Carbohydrate Research. - : Elsevier Ltd.. - 0008-6215 .- 1873-426X. ; 345:10, s. 1331-1338 Tidskriftsartikel (refereegranskat)

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