- Enzymatic Synthesis of 2-(β-Galactosyl)-ethyl Methacrylate by β-Galactosidase from Pyrococcus woesei and Application for Glycopolymer Synthesis and Lectin Studies
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Glycosidases have long been used for the synthesis of glycosides by transglycosylation reactions. Especially glycosidases from hyperthermophilic bacteria are useful for reactions under extreme reaction conditions, e.g., in the presence of organic solvents. We herein report the facile enzymatic synthesis and purification of 2-(β-galactosyl)-ethyl methacrylate (Gal-EMA) with the recombinant hyperthermostable glycosidase from Pyrococcus woesei in high yields. Optimized reaction conditions resulted in gram-scale synthesis of the galactosylated monomer with 88% transglycosylation yield. The product Gal-EMA was characterized by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS), nuclear magnetic resonance (NMR) spectroscopy, and infrared (IR) spectroscopy. Gal-EMA was utilized to synthesize sugar-functionalized acrylate polymers with defined amounts of incorporated galactose (0-100%). Analysis of the binding affinity of the lectin RCA120 from Ricinus communis to the glycopolymers using an enzyme-linked lectin assay (ELLA) revealed KD values between 0.24 and 6.2 nM, depending on the amount of incorporated Gal-EMA. The potential of Gal-EMA for the synthesis of acrylate-functionalized glycan oligomers was demonstrated by sequential elongation of the terminal galactose by two glycosyltransferases, resulting in the terminal glycan N-acetyllactosamine (LacNAc) epitope. In conclusion, the enzymatic synthesis of Gal-EMA opens new routes to a series of novel monomeric building blocks for the synthesis of glycan-functionalized polyacrylates.
- Hoffmann, Marius,Gau, Elisabeth,Braun, Susanne,Pich, Andrij,Elling, Lothar
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p. 974 - 987
(2020/03/03)
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- CARBOHYDRATE-BASED COMPOSITIONS AND METHODS FOR TARGETED DRUG DELIVERY
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Provided herein are compositions and methods for intracellular delivery. The compositions are polymer compositions in which the polymer serves as a carrier for therapeutic and/or diagnostic agents. The polymer compositions are effective in targeted delivery of therapeutic and/or diagnostic agents to a cell. The polymer compositions include a targeting moiety that includes carbohydrate groups that effectively target specific cell surface receptors. The polymer compositions also include an agent binding moiety that effectively associates the therapeutic and/or diagnostic agent to be delivered to the cell.
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- Glycosylation using unprotected alkynyl donors
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(Chemical Equation Presented) Gold(III) activation of unprotected propargyl glycosyl donors has been shown to be effective for the synthesis of saccharides. Terminal propargyl glycosides of glucose, galactose, and mannose required heating at reflux in ace
- Mamidyala, Sreeman K.,Finn
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experimental part
p. 8417 - 8420
(2010/01/16)
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- Facile in situ preparation of biologically active multivalent glyconanoparticles
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Biologically active multivalent glyconanoparticles are prepared in an extremely simple method by reduction of well-defined glycopolymers, prepared by RAFT polymerisation, in an aqueous solution of HAuCl4. The Royal Society of Chemistry 2006.
- Spain, Sebastian G.,Albertin, Luca,Cameron, Neil R.
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p. 4198 - 4200
(2007/10/03)
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- Investigation of the interaction between peanut agglutinin and synthetic glycopolymeric multivalent ligands
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The interaction between synthetic glycoplymers bearing β-D-galactose side groups and the lectin peanut agglutinin (PNA) was investigated by UV-difference spectroscopy and isothermal titration calorimetry (ITC). UV-difference spectroscopy indicated that the polymer-lectin interaction was stronger than that between PNA and either the corresponding monomer, D-galactose or D-lactose. The thermodynamics of binding (K, ΔG, ΔH, ΔS and n) were determined from ITC data by fitting with a two-site, non-cooperative binding model. It was found that the glycopolymer displayed around a 50 times greater affinity for the lectin than the parent carbohydrate, and around 10 times greater than the monomer, on a valency-corrected basis. Binding was found to be entropically driven, and was accompanied by aggregation and precipitation of protein molecules. Furthermore, interesting differences between polymers prepared either from deacetylated monomers, or by deacetylation of pre-formed polymers, were found. The Royal Society of Chemistry 2005.
- Ambrosi, Moira,Cameron, Neil R.,Davis, Benjamin G.,Stolnik, Snjezana
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p. 1476 - 1480
(2007/10/03)
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- Influence of preparation procedure on polymer composition: Synthesis and characterisation of polymethacrylates bearing β-D-glucopyranoside and β-D-galactopyranoside residues
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Methacrylate derivatives bearing β-D-glucopyranoside and β-D-galactopyranoside residues are synthesised by glycosylation of 2-hydroxyethyl methacrylate (HEMA) with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide and 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide, respectively. β-Selectivity in the glycosylation reactions is ensured by neighbouring-group participation of acetyl groups at O-2 in the glycosyl donors. 2-(2′,3′,4′,6′-tetraO-acetyl-β-D-glucosyloxy)ethyt methacrylate (AcGlcEMA, 1 a) was obtained as a crystalline solid and its crystal structure was determined by single-crystal X-ray diffraction. Deprotected polymers are synthesised in two parallel ways; either polymerisation of the protected monomers and subsequent deacetylation of the resulting polymers, or polymerisation of the previously deprotected monomers. The number- and weight-average relative molecular masses of both the protected and deprotected polymers are determined by size exclusion chromatography (SEC). Absolute molecular masses are obtained using the previously estimated refractive-index increments, dn/dc. It is found that polymerisation of deprotected monomers leads to polymers of well-defined composition, in contrast to the deacetylation of protected polymers.
- Ambrosi, Moira,Batsanov, Andrei S.,Cameron, Neil R.,Davis, Benjamin G.,Howard, Judith A.K.,Hunter, Rob
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