Linked Fucose Residues Research Articles

Characterization of the carbohydrate moiety of Clerodendron trichotomum lectins

Lectins were isolated from fruits and leaves of Clerodendron trichotomum by affinity chromatography on lactamyl-Sepharose. The purified lectins (C. trichotomum agglutinin: CTA) were homogeneous on SDS/polyacrylamide gel electrophoresis, and the carbohydrate moiety was characterized by physicochemical and immunochemical methods. The asparagine-linked oligosaccharides were released by treatment with N-oligosaccharide glycopeptidase (almond, EC 3.5.1.52) of peptic glycopeptides obtained from fruit CTA, and separated by gel filtration and thin-layer chromatography. The structure of the predominant oligosaccharide was determined as Xyl beta 1----2 (Man alpha 1----6)(Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4(Fuc alpha 1----3)GlcNAc by high-performance liquid chromatography, sugar analysis and 1H-NMR spectroscopy. The reactivity of the carbohydrate moiety of CTA toward various lectins was studied. Fruit and leaf CTAs were applied to polyacrylamide gel electrophoresis, transferred to nitrocellulose sheets and detected with horseradish-peroxidase-conjugated lectins. Concanavalin A, lentil lectin, pea lectin, Vicia faba lectin and Ulex europeus agglutinin I, but not wheat germ lectin, bound to fruit CTA. The results indicate new binding properties of these plant lectins: a beta-xylosyl residue substituted at C-2 of the beta-mannosyl residue of N-linked oligosaccharide does not affect the binding with mannose-specific lectins, lentil, pea and Vicia faba lectins can bind to N-linked oligosaccharides containing an alpha-L-fucosyl residue attached to C-3 of the asparagine-linked N-acetyl-D-glucosamine residue, and Ulex europeus agglutinin I can bind to the (alpha 1----3)-linked fucose residue of the N-linked oligosaccharide.

A 500-MHz1H-NMR study on theN-linked carbohydrate chain of bromelain

The 500-MHz1H-NMR characteristics of theN-linked carbohydrate chain Manα1-6[Xylβ1-2]Manβ1-4GlcNAcβ1-4[Fucα1-3]GlcNAcβ1-NAsn of the proteolytic enzyme bromelain (EC 3.4.22.4) from pineapple stem were determined for the oligosaccharide-alditol and the glycopeptide, obtained by hydrazinolysis and Pronase digestion, respectively. The1H-NMR structural-reporter-groups of the α(1–3)-linked fucose residue form unique sets of data for the alditol as well as for the glycopeptide.

Novel antigenic specificity involving the blood group antigen, Lea, in combination with onco-developmental antigen, SSEA-1, recognized by two monoclonal antibodies to human milk-fat globule membranes

Two monoclonal antibodies to human milk-fat globule membranes, which recognize an epithelial antigen designated MAM-3c, were found to bind strongly to epithelial glycoproteins derived from non-secretors. Further investigations, using purified glycoproteins and structurally defined ollgosaccharides, established that the optimal antigenic structure for both antibodies involves the Type 1 based blood group antigen. Lea. In combination with the Type 2 based onco-developmental antigen. SSEA-1. ▪ as in lacto-N-difucohexaose II. The antibodies may also react with the corresponding monofucosyl structures lacking the 3- or 4- linked fucose residues and to a lesser extent with the afucosyl tetrasaccharide sequence as in lacto-N-tetraose. The Lea and SSEA-1 antigens are known to occur on human epithelial glycoproteins. However, this is the first report of an antigenic specificity involving a combination of the Type 1 and Type 2 based fuco-oligosaccharides and occurring on epithelial glycoproteins.

1H NMR spectroscopy of carbohydrates from the G glycoprotein of vesicular stomatitis virus grown in parental and Lec4 Chinese hamster ovary cells

Carbohydrate moieties derived from the G glycoprotein of Vesicular Stomatitis Virus (VSV) grown in parental Chinese hamster ovary (CHO) cells and the glycosylation mutant Lec4 have been analyzed by high-field 1H NMR spectroscopy. The major glycopeptides of CHO VSV and Lec4 VSV were purified by their ability to bind to concanavalin A-Sepharose. The carbohydrates in this fraction are of the biantennary, complex type with heterogeneity in the presence of α(2,3)-linked sialic acid and α(1,6)-linked fucose residues. A minor CHO VSV glycopeptide fraction, which does not bind to concanavalin A-Sepharose but which binds to pea lectin-agarose, was also investigated by 1H NMR spectroscopy. These carbohydrates are complex moieties which appear to contain N-acetylglucosamine in β(1,6) linkage. Their spectral properties are most similar to those of a triantennary complex oligosaccharide containing a 2,6-disubstituted mannose α(1,6) residue. Carbohydrates of this type are not found among the glycopeptides of VSV grown in the Lec4 CHO glycosylation mutant.

Carbohydrates of the brown seaweeds himanthalia lorea and bifurcaria bifurcata: Part II. structural studies of the “fucans”

Methylation, periodate oxidation, and partial hydrolysis studies have revealed the essential similarity of the different fucose-containing polysaccharides separated from the title algae. The high-fucose, high sulphate-containing material more closely resembles the fucan reported in the literature and has (1→2)- and (1→3)-linked fucose residues with sulphation at C-4. The glucuronic acid and xylose residues are not sulphated and are on the periphery of highly branched molecules. In the polysaccharide having a high content of uronic acid, the fucose residues are similarly linked, and again the xylose and a large proportion of the glucuronic acid residues are present as end-group and (1→4)-linked units on the outside of the highly branched molecules. Partial hydrolysis studies proved the mutual linkage of the fucose (at C-3) and glucuronic acid, and the presence of an unidentified 6-deoxy sugar derivative which was also linked to glucuronic acid. Selective cleavage of the glucosiduronic acid linkages by Hofmann degradation of the amide derivative was unsuccessful.