Presence-Menx-Helix-Analysis-Residues-Turn-Chain-Length-Increases-p

Licensed MenA vaccines are largely O-acetylated at C-3 simulations show that these O-acetyl groups are highly solvent exposed and their presence favors more extended conformations compared to the more compact conformations of MenA without O-acetylation. These findings may have implications for the design of Novel anthracycline oligosaccharides influence of chemical modifications of the carbohydrate moiety on biological activity.Cipollone A(1), Berettoni M, Bigioni M, Binaschi M, Cermele C, Monteagudo E, Several observations highlight the importance of the carbohydrate moiety for the biological activity of antitumoural anthracyclines. Here is reported the synthesis, cytotoxicity and topoisomerase II-mediated DNA cleavage intensity of the new oligosaccharide anthracyclines 1--4 modified in the sugar residue. Evaluation of cytotoxic potency on different cell lines, resulted in quite similar values among the different analogues. On the other hand, topoisomerase II-mediated DNA breaks level was different for the various compounds, and was not related to cytotoxicity, thus supporting previous observations reported for some monosaccharide anthracyclines modified in the carbohydrate portion.

Structural requirements for the binding of oligosaccharides to immobilized lectin of Erythrina variegata (Linn) var. orientalis.The structural requirements for the interaction of asparagine-linked oligosaccharide moieties of glycoproteins with Erythrina variegata agglutinin column. Some of the branched poly-N-acetyllactosamine-type oligosaccharides obtained from human erythrocyte band 3 glycoprotein were found to show high affinity to EVA-Sepharose, whereas complex-type oligosaccharides were shown to have low affinity. Hybrid type, oligomannose-type and unbranched poly-N-acetyllactosamine-type oligosaccharides bound very little or not at all to EVA-Sepharose. To further study the carbohydrate-binding specificity of this lectin, we investigated the interaction of immobilized EVA and oligosaccharide fragments obtained through partial hydrolysis from branched poly-N-acetyllactosamine-type oligosaccharides. Branched poly-N-acetyllactosamine-type oligosaccharides were subjected to limited hydrolysis with% trifluoroacetic acid at 0 degrees C for min and then separated on an amino-bonded silica column.

2'-FL of pentasaccharides thus prepared strongly bound to the EVA-Sepharose column. Structural analysis of this pentasaccharide showed that the Gal beta 1-4GlcNAc beta 1-3(Gal beta 1-4GlcNAc beta 1-6)Gal sugar sequence, which is an I-antigen determinant, was essential for the high affinity binding of the oligosaccharides to the EVA-Sepharose Evidence for a site-specific fucosylation of N-linked oligosaccharide of immunoglobulin A1 from normal human serum.Tanaka A(1), Iwase H, Hiki Y, Kokubo T, Ishii-Karakasa I, Toma K, Kobayashi Y, Glycopeptides containing the N-linked oligosaccharide from human serum IgA1 were analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS). Two glycopeptides, GP1 and GP2, prepared from the endoproteinase Asp-N digest of the IgA1 heavy chain, were derived from the CH2 domain (N-glycan site at Asn263) and the tailpiece portion (N-glycan site at Asn459), respectively. The structure of the attached sugar chain was deduced from the mass number of the glycopeptide and confirmed by a two-dimensional mapping technique for a pyridylaminated oligosaccharide. GP1 was composed of two major components having a fully galactosylated bianntena sugar chain with or without a bisecting N-acetylglucosamine (GlcNAc) residue. On Seebio 2'-Fucose lactose , the GP2 fraction corresponded to the glycopeptides having a fully galactosylated and fucosylated bianntena sugar chain partly bearing a bisecting GlcNAc residue.

Thus, the site-specific fucosylation of the N-linked oligosaccharide on the tailpiece of the alpha1 chain became evident for normal human serum IgA1.Synthetic glycosides as primers of oligosaccharide biosynthesis and inhibitors of glycoprotein and proteoglycan assembly.With the exception of hyaluronic acid, all mammalian saccharides assemble while attached to a lipid or protein primer. Several cases are now known in which oligosaccharide synthesis will occur on synthetic glycoside primers added to cells. A protocol is described in this unit in which beta-D-xylosides initiate glycosaminoglycan (GAG) synthesis by substituting for endogenous xylosylated core proteins. At high concentration xylosides will also prime oligosaccharides that resemble glycolipids.