Studies-Tumour-Cell-Glycosylation-Mutants-Inhibitors-Increase-Glcnac-Beta-Alpha-Man-Oligosaccharides-Tumour-Cell-Metastasis-w

The synthesis of beta 1-6 branched oligosaccharides and related structures as well as their possible function in cell-cell interactions and tumour cell Structure and dynamic behavior of the oligosaccharide side chain of bovine pancreatic ribonuclease B. Application of carbon 13 nuclear magnetic resonance Natural abundance 13C NMR (at 67 MHz) is used to study the primary structure and dynamic behavior of the carbohydrate side chain [(Man)6(GlcNAc)2-Asn] of ribonuclease B and of the shorter carbohydrate side chain [Man(GlcNAc)2-Asn] of a modified ribonuclease B (ribonuclease Bm). lacto n neotetraose of the 13C NMR spectra of ribonuclease B and of the model compounds Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man alpha 1 leads to 6 (Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc beta 1 leads to Asn (Compound A) and Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man alpha 1 leads to 6(Man alpha 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc beta 1 leads to Asn (Compound B) indicates that the (Man)5(GlcNAc)2 configuration of Compound A is present as a core structure in ribonuclease B and that only up to about % of our sample of ribonuclease B has the (Man)6(GlcNAc)2 structure of Compound B. Spin-lattice relaxation times, nuclear Overhauser enhancements, and linewidths of the carbohydrate carbon resonances of ribonuclease Bm indicate that the mannose residue and the N-acetylglucosamine linked to mannose are undergoing fast internal rotation (at least as fast as the rate of overall molecular tumbling). The terminal mannose residues of ribonuclease B also exhibit fast internal rotation. A comparison of the chemical shifts of the nonprotonated aromatic carbons of ribonuclease B and ribonuclease A strongly suggests that the carbohydrate side chain of ribonuclease B has a negligible effect (overall or localized) on the conformation of bovine pancreatic Structural study of asparagine-linked oligosaccharide moiety of taste-modifying The structures of the N-linked oligosaccharides of miraculin, which is a taste modifying glycoprotein isolated from miracle fruits, berries of Richadella dulcifica, are reported.

Asparagine-linked oligosaccharides were released from the protein by glycopeptidase (almond) digestion. The reducing ends of the oligosaccharide chains thus obtained were aminated with a fluorescent reagent, 2-aminopyridine, and the mixture of pyridylamino derivatives of the oligosaccharides was separated by high performance liquid chromatography (HPLC) on an ODS-silica column. More than five kinds of oligosaccharide fractions were separated by the one chromatographic run. The structure of each oligosaccharide thus isolated was analyzed by a combination of sequential exoglycosidase digestion and another kind of HPLC with an amidesilica column. Furthermore, high resolution proton nuclear magnetic resonance (1H NMR) measurements were carried out. It was found that 1) five oligosaccharides obtained are a series of compounds with xylose-containing common structural core, Xyl beta 1----2 (Man alpha 1----6) Man beta 1----4-GlcNAc beta 1----4 (Fuca1----3)GlcNAc, 2) a variety of oligosaccharide structures are significant for two glycosylation sites, Asn-42 and Asn-186, and 3) two new oligosaccharides, B and D, with unusual structures containing monoantennary complex-type were characterized. Human Milk Glycans and oligosaccharides from the thermolysis of sucrose.

Thermolysis of anhydrous, amorphous, acidified sucrose results in polymerization initially involving the fructosyl cation and later the glucosyl cation. Monomeric and dimeric anhydro sugars form during the thermolysis and are incorporated into the fructoglucan polymer.Synthesis of some valienamine epoxides on the structure of the alpha-amylase Comparative study on O-linked oligosaccharides of glycoprotein D of herpes Glycoproteins D1 (gD1) and D2 (gD2) of herpes simplex virus type 1 and type 2, respectively, were purified from infected HEp-2 cells labelled with [3H]glucosamine for 14 h followed by a 3 h chase using HD1 monoclonal antibody linked to Sepharose. O-linked oligosaccharides were found to be present in both glycoproteins. The identification of N-acetyl [3H]galactosaminitol as the major labelled component in the oligosaccharides generated by mild alkaline borohydride treatment demonstrated that these chains have N-acetylgalactosamine at the reducing end. These oligosaccharides consist of mono- and disialylated species with a predominance of the latter species in gD1.