- Solid-Phase Enzymatic Synthesis of a Sialyl Lewis X Tetrasaccharide on a Sepharose Matrix
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Thiopyridyl Sepharoses with different linker arm lengths were prepared from epoxy Sepharose 6B by reaction first with 1,8-diamino-3,6-dioxaoctane and then with, sucessively, diethoxy-3-cyclobutene-1,2-dione (squaric acid diethyl ester) and 1,8-diamino-3,6-dioxaoctane in several cycles, followed by reaction of the obtained amino Sepharoses with, successively, thiobutyrolactone and 2,2′-dithiopyridine. The thiopyridyl Sepharoses were reacted with the glucosamine derivative 2-(3′-mercaptobutyrylamido)ethyl 2-acetamido-2-deoxy-β-D-glucopyranoside, giving GlcNAc Sepharoses with different linker lengths. Enzymatic galactosylation of these with β-(1-4)-galactosyltransferase and UDP-galactose gave yields varying between 70 and 98%, and there was a clear correlation between linker length and yield. A GlcNAc Sepharose with a long linker was then used in a solid-phase synthesis of a sialyl Le x tetrasaccharide. The three required enzymes (galactosyl-, sialyl, and fucosyltransferase) and nucleotide sugars were reacted consecutively with the GlcNAc Sepharose, giving, after cleavage from Sepharose with DTT, the free sialyl Le x tetrasaccharide derivative in a 57% total yield after purification.
- Blixt,Norberg
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- Chemo-enzymatic synthesis of functionalized oligomers of N-acetyllactosamine glycan derivatives and their immobilization on biomaterial surfaces
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Poly-N-acetyllactosamines (poly-LacNAc, [-3Gal(β1-4)GlcNAc(β1-] n) are terminal glycan structures present in glycoproteins and glycolipids. Their biological functions as ligands for galectins and as carriers of glycan epitopes are well documented. In the present paper we have characterized six novel functionalized β-d-GlcNAc derivatives, including aglyca of varying hydrophobicity and molecular weight, as substrates for recombinant human β1,4 galactosyltransferase 1 (β4GalT-1). The sugar derivatives carry short or long amino- or azide-terminated linker molecules for further modification or immobilization. The linker chemistry had an impact on enzyme kinetics and enzymatic syntheses of N-acetyllactosamine derivatives (LacNAc, Gal(β1-4)GlcNAc(β1-R). The combination of β4GalT-1 with bacterial β1,3-N-acetylglucosaminyltransferase (β3GlcNAc-T) resulted in the preparative syntheses of LacNAc oligomers with up to three LacNAc repeating units. All products were characterized by NMR and MS. The obtained LacNAc glycans were immobilized onto microtiter plates and their efficiency of binding of fungal galectin CGL2 was determined.
- Adamiak, Kathrin,Anders, Thorsten,Henze, Manja,Keul, Helmut,Moeller, Martin,Elling, Lothar
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- Double targeting hepatic tumor drug as well as synthetic method and application thereof
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The invention relates to a double targeting hepatic tumor drug as well as a synthetic method and application thereof. The double targeting hepatic tumor drug has a terminal structure (galactose or N-acetyl galactose) capable of specifically binding to asialoglycoprotein receptor at the surface of a hepatocyte, and therefore the double targeting hepatic tumor drug is capable of binding to the asialoglycoprotein receptor so as to be brought into the interior of a hepatic tumor cell by means of the endocytosis of the hepatic tumor cell. On the other hand, experiments prove that the enzyme hydrolysis of the overexpressed cathepsin B in hepatic tumor cell lysosome is performed on the double targeting hepatic tumor drug to release Adriamycin, that is, active ingredients are released while the level of cathepsin B can be reduced, so as to slow down tumor progression. In summary, the double targeting hepatic tumor drug prepared by the invention uses asialoglycoprotein receptor and cathepsin Bas double target spots for having an effect, has obvious therapeutic effect, and meanwhile significantly reduces the toxic and side effects on other normal tissues and cells.
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Paragraph 0050; 0051; 0052; 0053; 0054; 0056
(2019/01/15)
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- Preparation of oligosaccharides by homogenous enzymatic synthesis and solid phase extraction
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This communication describes a method for enzymatic preparation of bioactive glycans, which integrated the high-efficiency of homogenous phase enzymatic reaction and fast separation of solid phase extraction.
- Wang, Wenjun,Jin, Chen,Guo, Lina,Liu, Yu,Wan, Yue,Wang, Xin,Li, Lei,Zhao, Wei,Wang, Peng George
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p. 11240 - 11242
(2011/12/05)
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- Photo-click immobilization on quartz crystal microbalance sensors for selective carbohydrate-protein interaction analyses
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A photoclick method based on azide photoligation and Cu-catalyzed azide-alkyne cycloaddition has been evaluated for the immobilization of carbohydrates to polymeric materials. The biomolecular recognition properties of the materials have been investigated with regard to applicable polymeric substrates and selectivity of protein binding. The method was used to functionalize a range of polymeric surfaces (polystyrene, polyacrylamide, polyethylene glycol), poly(2-ethyl-2-oxazoline), and polypropene) with various carbohydrate structures (based on α-D-mannose, β-D-galactose, and N-acetyl-β-D-glucosamine). The functionalized surfaces were evaluated in real-time studies of protein-carbohydrate interactions using a quartz crystal microbalance flow-through system with a series of different carbohydrate-binding proteins (lectins). The method proved to be robust and versatile, resulting in a range of efficient sensors showing high and predictable protein selectivities.
- Norberg, Oscar,Deng, Lingquan,Aastrup, Teodor,Yan, Mingdi,Ramstroem, Olof
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p. 1000 - 1007
(2011/10/09)
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- Carbohydrate microarrays for assaying galactosyltransferase activity
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Carbohydrate microarrays have been used recently for the rapid analysis of glycan-protein or glycan-cell interactions and for the detection of pathogens. As a demonstration of its significance and versatility, the microarray technology has been applied in this effort to assay glycosyltransferase activities. In addition, carbohydrate microarray based methods have been employed to quantitatively determine binding affinities between lectins and carbohydrates.
- Park, Sungjin,Shin, Injae
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p. 1675 - 1678
(2008/02/02)
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- Synthesis of oligosaccharides related to the HNK-1 antigen. 5. Synthesis of a sulfo-mimetic of the HNK-1 antigenic trisaccharide
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2-Aminoethyl 3,6-di-O-sulfo-β-D-glucopyranosyl-(1→3)-β-D- galactopyranosyl-(1→4)-2-acetamido-2-deoxy-β-D-glucopyranoside, which is the sulfo-mimetic of the antigenic trisaccharide HNK-1, and the corresponding monosulfates, viz., 2-aminoethyl 3-O-sulfo-and 2-aminoethyl 6-O-sulfo-β-D-glucopyranosyl-(1→3)-β-D-galactopyranosyl-(1→ 4)-2-acetamido-2-deoxy-β-D-glucopyranosides, were synthesized. 2-Azidoethyl 2,4-di-O-benzoyl-β-D-glucopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-β- D-galactopyranosyl-(1→ 4)-2-acetamido-3,6-di-O-benzyl-2-deoxy-β-D- glucopyranoside served as the common precursor for the sulfated trisaccharides. This compound was synthesized according to the [2+1] pattern from monosaccharidic precursors: 3,6-di-O-acetyl-2,4-di-O-benzoyl-D-glucopyranosyl trichloroacetimidate, allyl 2-O-benzoyl-4,6-O-benzylidene-β-D- galactopyranoside, and 2-azidoethyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-β- D-glucopyranoside. The structures of the glycosyl donors and glycosylation conditions were optimized for the efficient synthesis of the glucosyl-β-(1→3)-galactose disaccharide block and its subsequent transformation into the target trisaccharide sequence.
- Sukhova,Dubrovskii,Tsvetkov,Nifantiev
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p. 1655 - 1670
(2008/09/18)
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- Preparation of synthetic glycoconjugates as potential vaccines against Shigella flexneri serotype 2a disease
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The synthesis of three neoglycopeptides incorporating carbohydrate haptens, differing in length, covalently linked to a non natural universal T helper peptide is disclosed. They were synthesized according to a blockwise strategy based on the condensation
- Wright, Karen,Guerreiro, Catherine,Laurent, Isabelle,Baleux, Francoise,Mulard, Laurence A.
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p. 1518 - 1527
(2007/10/03)
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