Comparison-Carbohydrate-Chains-Glycoproteins-Type-Alpha-Mutant-g

Analysis of the wild-type galactomannoprotein showed that it contained a heterogeneous small core oligosaccharide fraction linked to asparagine with sugar compositions that ranged from Man9(GlcNAc)2- to Gal4Man(GlcNAc)2-. The galactose units are in terminal positions of a Man(GlcNAc)2- unit that is similar to the mannoprotein core of Saccharomyces cerevisiae. Attached to this core in a larger oligosaccharide fraction is an alpha 1--6-linked polymannose chain that is substituted at position 2 with alpha-linked mannose and galactose. The O-linked sugars consist of mannose, alpha 1--2-linked mannosylmannose and alpha 1--2-linked galactosylmannose, along with small amounts of tri- and tetrasaccharides. The glycosylation mutant lacks alpha 1--2-linked mannose on both the O-linked chains and the outer chain of the large N-linked chains, suggesting that it may be defective in regulation of an alpha 1,2-mannosyltransferase that adds mannose to glycoproteins in the Golgi.Identification of the specific oligosaccharide sites recognized by type 1 fimbriae from Escherichia coli on nonspecific cross-reacting antigen, a CD66 Nonspecific cross-reacting antigen (NCA), a CD66 cluster antigen, is a well characterized glycoprotein on granulocytes, macrophages, and lung epithelium.

Structural studies at the protein and genomic levels have revealed that NCA is a member of the immunoglobulin (Ig) supergene family and contains a domain structure similar to Ig with an amino-terminal variable-like domain followed by disulfide loop-containing constant-like domains. Previous work by this laboratory and others has demonstrated that NCA is a receptor for binding of bacteria expressing type 1 fimbriae (pili). This binding is mediated by interaction between lectins on the bacteria fimbriae and carbohydrate chains on NCA. In the present work we further characterize the specificity for bacterial binding by NCA using endoglycosidases and site-directed mutagenesis. 2'-Fucose lactose of these studies demonstrate that Escherichia coli expressing type 1 fimbriae binds to high mannose oligosaccharide structures on NCA and that the functionally relevant sites are located in the variable-like domain of NCA.Structures of monosialyl oligosaccharides isolated from the respiratory mucins of a non-secretor (O, Lea+b-) patient suffering from chronic bronchitis. Characterization of a novel type of mucin carbohydrate core structure.

Mucin glycopeptides were prepared from the respiratory mucus of a non-secretor, chronic bronchitis patient with blood group O, Le(a)+b-. Oligosaccharides were released by alkaline borohydride treatment and purified by anion-exchange chromatography, size-exclusion chromatography and high-performance liquid chromatography on a silica-bonded alkylamine column. Structural studies employed 0-MHz 1H-NMR spectroscopy and fast atom bombardment-mass spectrometry. Snag it now -six monosialyl oligosaccharides, ranging in size from di- to octasaccharide, were fully characterized in this study. The sialic acid occurs either alpha(2--3)- or alpha(2--6)-linked to a galactosyl residue, or alpha(2--6)-linked to GalNAc-ol. In keeping with the non-secretor status of the patient, no structures with an alpha(--2)-linked fucose residue were found. Nine of the structures had fucose present in alpha(--3) linkage, either in the Le(x) determinant or in the sialyl-Le(x) determinant, or both (structure 11).

Only one oligosaccharide (structure 3b) was seen with fucose alpha mucins of the non-secretor patient had not been found previously in the respiratory mucins of secretor individuals; they are listed below. Among these, structure 4 alpha represents a novel type of mucin carbohydrate core structure.Delineating functional properties of a cello-oligosaccharide and β-glucan specific cellobiohydrolase (GH5_38) Its synergism with Cel6A and Cel7A for 61, South Africa; Department of Plant Sciences, University of the Free State, Cellulase cocktails formulated to degrade crystalline cellulose generally contain cellobiohydrolases (CBHs), referred to as CBHI (Cel7A) and CBHII and CBHII improve the release of fermentable sugars (β-1,4-cellobiose as the main product) from crystalline cellulose. In this study, a novel cellobiohydrolase (Exg-D) sourced from a metagenome of hindgut bacterial symbionts of a termite was heterologouly expressed, purified, and functionally characterised. Exg-D specific activity was higher on insoluble barley β-glucan β-glucan (89 Umg protein) compared to cellulosic substrates; Avicel and CMC.