Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Sialyl trisaccharide

Y. Ichikawa, J. L.-C. Liu, G.-J. Shen, and C.-H. Wong, A highly efficient multienzyme system for the one-step synthesis of sialyl trisaccharide In situ generation of sialic acid and TV-acetyllactosamine coupled with regeneration of UDP-glucose, UDP-galactose, and CMP-sialic acid, J. Am. Chem. Soc. 113 6300 (1991). [Pg.337]

Gal-(1— 3)-D-GalNAc. By using 0.7 U of STB, as a soluble preparation readily obtained from 300 g of porcine liver, the sialylation of /J-D-Gal-(1 — 3)-d-G1cNAc was performed on a one-mmol scale and sialylated trisaccharide 65 was obtained in 21 % isolated yield. In this respect, the purification of reaction mixtures is still troublesome, especially because of the presence of Triton X-100 from our experience, the use of immobilized enzymes, eliminating the need for detergent, greatly facilitates the purification procedure. [Pg.237]

Synthesis of Sialyated Trisaccharides. We have used a combination of glycosidases and glycosyltranferases to prepare sialylated trisaccharides (Equations 8-9). The enzyme P-galactosidase from bovine... [Pg.59]

The immobilized enzyme was used for repeated synthesis of the above sialylated trisaccharides without adding detergent to the system, which was used in previous synthesis with the soluble enzyme (42), The use of detergent complicates isolation of the products. The stability of the enzyme preparation was good and no decrease of activity was observed on repeated preparative synthesis. Recently, immobilization to CNBr-activated agarose of the a2-6sialyltransferase was reported (50),... [Pg.59]

Based on the abiHty of the E. coli NeuA to produce 9-glycosylated KDN 47 from a disaccharide 46 aldol acceptor, the synthesis of the unusual a-2,3- and a-2,6-linked sialylated trisaccharide 48 and tetrasaccharide 49 was reported, in which sialic acids are hnked in both the terminal and reducing positions (Scheme 17.17) [43]. Each transformation was conducted as a one-pot two-step cascade using a combination of CSS and one of the complementary SiaT types. [Pg.383]

Scheme 13. Enzymatic synthesis of a sialylated trisaccharide derivative, by stepwise sugar-chain elongation, using a water-soluble chymotrypsin-sensitive glycopolymer. Reagents i) 1. HEPES buffer pH 6, UDP-Gal (1.5 eq.), GT, 37 °C, 24 h 2. cacodylate buffer pH 7.4, ST6, CIAP, CMP-NeuAc (1.5 eq.), 37°C, 48 h, gel filtration on Sephadex G-25, q.y. ii) 1. a-chymotrypsin, Tris HCl buffer pH 7.8, 40 °C, 24 h 2. gel filtration on Sephadex G-15, 87%. Scheme 13. Enzymatic synthesis of a sialylated trisaccharide derivative, by stepwise sugar-chain elongation, using a water-soluble chymotrypsin-sensitive glycopolymer. Reagents i) 1. HEPES buffer pH 6, UDP-Gal (1.5 eq.), GT, 37 °C, 24 h 2. cacodylate buffer pH 7.4, ST6, CIAP, CMP-NeuAc (1.5 eq.), 37°C, 48 h, gel filtration on Sephadex G-25, q.y. ii) 1. a-chymotrypsin, Tris HCl buffer pH 7.8, 40 °C, 24 h 2. gel filtration on Sephadex G-15, 87%.
By carefully adjusting the distances between two sialoside residues in a number of divalent clusters. Click and Knowles [105] have obtained dimer 104 having the two sialic acid 5.7 nm apart. Compound 104 was 100-fold more potent than methyl a-sialoside (Neu5Aca2Me) in influenza virus inhibitions and 500-fold more potent in the case of polyomia virus. Alternatively, sialyl-a-(2,6)-/3-LacNAc dimers (105) branched at different positions of synthetic peptides, including compact glycine-rich and helical proline-rich peptides, afforded clusters which were only 8- and 4-fold more potent, respectively, than the corresponding monovalent trisaccharide [106]. [Pg.264]

Lex-antigenic trisaccharide (a-L-Fuc(l-3)-[p-D-Gal-(l-4)-p-D-GlcNAc]) and its sialylated structure (SLex) are terminal components of a nnmber of glycoconjugates on cell surfaces [31]. SLex serves as a ligand for the endothelial leukocyte molecule-1 (E-selectin) [32], which mediates the initial stages of adhesion of leukocytes to activated endothelial cells, and pays a critical role during inflammatory responses [33]. Lex-based carbohydrates have shown promise in therapeutic investigations related to the inflammatory process. As a result, extensive efforts have been directed toward the synthesis of SLex and related molecules [34 also see Chap. 15],... [Pg.420]

Most sialylations so far reported have been achieved with soluble transferases, and seldom on a more than 20-/imol scale (see Table IX), with the intention to prepare and describe sequences present in glycoproteins and glycolipids. Trisaccharide < -D-Neu5Ac-(2— 3)-/J-D-Galp-(l — 3)-/J-d-... [Pg.225]

The preparation of trisaccharide 63 illustrates the activation and enzymic coupling of the 9-acetate of vV-acetylneuraminic acid, This involves the utilization of enzymes in a cascade of reactions which probably do not occur in cells (a) synthesis of Neu5,9Ac2 from the 6-acetate of vV-acetylmannosa-mine with the catabolic sialyl aldolase, (b) activation with CMPNeu5Ac synthetase, and (c) coupling. Acetylation in cells seems posterior to coupling. Terminal nonreducing vV-acetyl-9-O-acetylneuraminic acid residues appear... [Pg.229]

The 3-OH group of lactose or IV-acetyl-lactosamine is the site of glycosylation in some biologically important glycoprotein and glycolipids.75 For instance, L-fucose is linked to 0-3 of IV-acetyl-lactosamine in the Lewisx trisaccharide determinant (25), and sialic acid is linked to 0-3 of the galactose residue in sialyl... [Pg.156]

SCHEME 5.16 Use of an ALacetyl-4-0,5-ALoxazolidinone-protected sialyl phosphate in a one-pot trisaccharide synthesis. [Pg.145]


See other pages where Sialyl trisaccharide is mentioned: [Pg.172]    [Pg.51]    [Pg.393]    [Pg.654]    [Pg.91]    [Pg.301]    [Pg.289]    [Pg.270]    [Pg.172]    [Pg.51]    [Pg.393]    [Pg.654]    [Pg.91]    [Pg.301]    [Pg.289]    [Pg.270]    [Pg.155]    [Pg.180]    [Pg.182]    [Pg.312]    [Pg.270]    [Pg.29]    [Pg.105]    [Pg.265]    [Pg.47]    [Pg.264]    [Pg.357]    [Pg.430]    [Pg.501]    [Pg.138]    [Pg.143]    [Pg.176]    [Pg.199]   
See also in sourсe #XX -- [ Pg.71 ]




SEARCH



Sialyl

Sialylated

Sialylation

© 2024 chempedia.info