- Design and synthesis of trivalent Tn glycoconjugate polymers by nitroxide-mediated polymerization
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A new synthetic method for preparing Tn glycoconjugate polymers, containing tumor-associated carbohydrate antigens, by controlled living radical polymerization is reported. To mimic the authentic structures of Tn glycopeptide antigens and to explore the controlled living radical polymerization, three tumor-associated carbohydrate antigens (GalNAc, GalNAcα1-O-Ser, and GalNAcα1-O-Thr) were attached to a styrene-type monomer through a diethylene glycol spacer. Under nitroxide-mediated polymerization, controlled living radical polymerization proceeded to afford defined glycopeptide polymers with different Tn densities and compositions. The polydispersity index (PDI) and molecular weights were increased and conversions were decreased upon increasing the concentration of Tn glycoconjugate monomers. The resulting Tn glycoconjugate polymers were characterized by NMR and IR. The spectral data indicate that the Tn glycoconjugate moiety did attach to the polymer chain and Tn glycoconjugate density could be adjusted through the nitroxide-mediated polymerization conditions. The number of Tn units containing in the polymer chains could be estimated by NMR integration. This synthetic approach provides a new and efficient tool for constructing novel Tn glycoconjugate polymers.
- Liu, Si-Xian,Tsai, Yun-Tzu,Lin, Yu-Tung,Li, Jia-Yue,Chang, Che-Chien
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- Polypeptide raw material N-fluorenylmethoxycarbonyl-O-tert-butyl threonine preparation method
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The invention discloses a polypeptide raw material N-fluorenylmethoxycarbonyl-O-tert-butyl threonine preparation method, and mainly solves the technical problems of complexity, long cycle, more wastegas, waste water and industrial residues, high cost, high dangerousness and the like in an original process. The preparation method includes the steps: first, suspending threonine in methanol, reducing temperature, dropping thionyl chloride and then removing solvents by concentration after temperature reaction to obtain threonine methyl ester hydrochloride; second, dissolving the threonine methylester hydrochloride in methylene dichloride, leading in isobutene, concentrating sulfuric acid and performing sealed reaction treatment to obtain oily O-tert-butyl threonine methyl ester; third, dissolving the O-tert-butyl threonine methyl ester in water and acetone, adding sodium hydroxide, enabling pH (potential of hydrogen) to be 11-12, performing reaction to obtain O-tert-butyl threonine solution, adding 9-fluorenylmethyl-N-succinimidyl carbonate, maintaining the pH of 8-9 of a system by the aid of alkali liquor, performing washing acidification extraction after reaction and performing treatment to obtain N-fluorenylmethoxycarbonyl-O-tert-butyl threonine serving as a final product.
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Paragraph 0012-0015
(2019/01/23)
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- Synthetic MUC1 antitumor vaccine with incorporated 2,3-sialyl-T carbohydrate antigen inducing strong immune responses with isotype specificity
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The endothelial glycoprotein MUC1 is known to underlie alterations in cancer by means of aberrant glycosylation accompanied by changes in morphology. The heavily shortened glycans induce a collapse of the peptide backbone and enable accessibility of the latter to immune cells, rendering it a tumor-associated antigen. Synthetic vaccines based on MUC1 tandem repeat motifs, comprising tumor-associated 2,3-sialyl-T antigen, conjugated to the immunostimulating tetanus toxoid, are reported herein. Immunization with these vaccines in a simple water/oil emulsion produced a strong immune response in mice to which stimulation with complete Freund’s adjuvant (CFA) was not superior. In both cases, high levels of IgG1 and IgG2a/b were induced in C57BL/6 mice. Additional glycosylation in the immunodominant PDTRP domain led to improved binding of the induced antisera to MCF-7 breast tumor cells, compared with that of the monoglycosylated peptide vaccine.
- Stra?burger, David,Glaffig, Markus,Stergiou, Natascha,Bialas, Sabrina,Besenius, Pol,Schmitt, Edgar,Kunz, Horst
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p. 1142 - 1146
(2018/10/21)
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- Synthesis of tumor-associated MUC1-glycopeptides and their multivalent presentation by functionalized gold colloids
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The mucin MUC1 is a glycoprotein involved in fundamental biological processes, which can be found over-expressed and with a distinctly altered glycan pattern on epithelial tumor cells; thus it is a promising target structure in the quest for effective carbohydrate-based cancer vaccines and immunotherapeutics. Natural glycopeptide antigens indicate only a low immunogenicity and a T-cell independent immune response; however, this major drawback can be overcome by coupling of glycopeptide antigens multivalently to immunostimulating carrier platforms. In particular, gold nanoparticles are well suited as templates for the multivalent presentation of glycopeptide antigens, due to their remarkably high surface-to-volume ratio in combination with their high biostability. In this work the synthesis of novel MUC1-glycopeptide antigens and their coupling to gold nanoparticles of different sizes are presented. In addition, the development of a new dot-blot immunoassay to test the potential antigen-antibody binding is introduced.
- Tavernaro, Isabella,Hartmann, Sebastian,Sommer, Laura,Hausmann, Heike,Rohner, Christian,Ruehl, Martin,Hoffmann-Roeder, Anja,Schlecht, Sabine
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- Synthesis of Tn/T antigen MUC1 glycopeptide BSA conjugates and their evaluation as vaccines
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The tumor-associated mucin MUC1 over-expressed in most epithelial tumor tissues is considered a promising target for immunotherapy. The extracellular part of MUC1 contains a domain of numerous tandem repeats of the amino acid sequence HGVTSAPDTRPAPGSTAPPA, including five potential O-glycosylation sites. In this study, T9 and S15 have been chosen as the positions of glycosylation. The glycopeptides N-terminally equipped with a triethylene glycol spacer were synthesized by microwave-assisted Fmoc solid-phase peptide synthesis. After detachment from the resin and deprotection, the MUC1 glycopeptides were conjugated to bovine serum albumin (BSA). To evaluate the immunological properties, balb/c mice were immunized with these BSA vaccines. Copyright
- Cai, Hui,Huang, Zhi-Hua,Shi, Lei,Zou, Peng,Zhao, Yu-Fen,Kunz, Horst,Li, Yan-Mei
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scheme or table
p. 3685 - 3689
(2011/09/21)
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- Caged phospho-amino acid building blocks for solid-phase peptide synthesis
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Three 1-(2-nitrophenyl)ethyl-caged phosphoamino acids have been synthesized for use in standard Nα-fluorenylmethoxycarbonyl-based solid-phase peptide synthesis (SPPS). The most common naturally occurring phosphoamino acids, serine, threonine, and tyrosine, were prepared as protected caged building blocks by modification with a unique phosphitylating reagent. In previous work, caged phospho-peptides were made using an interassembly approach (Rothman, D. M.; Vazquez, M. E.; Vogel, E. M.; Imperiali, B. Org. Lett. 2002, 4, 2865-2868). However, this technique is limited to creating peptides without oxidation sensitive residues C-terminal to the amino acid to be modified and the methodology involves synthetic manipulations on the solid phase that may limit the utilization of the methodology. Herein we report the facile synthesis of N-α-Fmoc-phospho(1-nitrophenylethyl-2-cyanoethyl)-L-serine 1, N-α-Fmoc-phospho(1-nitrophenylethyl-2-cyanoethyl)-L-threonine 2, and N-α-Fmoc-phospho(1-nitrophenylethyl-2-cyanoethyl)-L-tyrosine 3. These building blocks allow the synthesis of any caged phospho-peptide sequence using standard Fmoc-based SPPS procedures.
- Rothman, Deborah M.,Vazquez, M. Eugenio,Vogel, Elizabeth M.,Imperiali, Barbara
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p. 6795 - 6798
(2007/10/03)
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- Synthesis of O-Glycopeptides of the N-Terminus of Interleukin-2
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The synthesis of a number of O-glycopeptides with different lengths of chain of between 3 and 10 amino acids that are part of the N-terminus of interleukin-2 is described.The key intermediate for the syntheses is O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-galactopyranosyl)-N-(9-fluorenylmethoxycarbonyl)-L-threonine tert-butyl ester (9b), to which suitably protected amino acids and peptides can be added C- or N-terminally. 9b is an element, which allows to insert glycosylated hydroxyamino acids with the Fmoc/tBu combination of protective groups, which are approved in peptide synthesis.During the syntheses peptide blocks are used.With the deprotected products it is possible to test the structural specificity of glycosyl transferases.
- Paulsen, Hans,Adermann, Knut
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p. 751 - 770
(2007/10/02)
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