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Background: Complex carbohydrate structures, glycans, are essential components of glycoproteins, glycolipids, and proteoglycans. While individual glycan structures including the SSEA and Tra antigens are already used to define undifferentiated human embryonic stem cells (hESC), the whole spectrum of stem cell glycans has remained unknown. We undertook a global study of the asparagine-linked glycoprotein glycans (N-glycans) of hESC and their differentiated progeny using MALDI-TOF mass spectrometric and NMR spectroscopic profiling. Structural analyses were performed by specific glycosidase enzymes and mass spectrometric fragmentation analyses. Results: The data demonstrated that hESC have a characteristic N-glycome which consists of both a constant part and a variable part that changes during hESC differentiation. hESC-associated Nglycans were downregulated and new structures emerged in the differentiated cells. Previously mouse embryonic stem cells have been associated with complex fucosylation by use of SSEA-1 antibody. In the present study we found that complex fucosylation was the most characteristic glycosylation feature also in undifferentiated hESC. The most abundant complex fucosylated structures were Lex and H type 2 antennae in sialylated complex-type N-glycans. Conclusion: The N-glycan phenotype of hESC was shown to reflect their differentiation stage. During differentiation, hESC-associated N-glycan features were replaced by differentiated cellassociated structures. The results indicated that hESC differentiation stage can be determined by direct analysis of the N-glycan profile. These results provide the first overview of the N-glycan profile of hESC and form the basis for future strategies to target stem cell glycans. [ABSTRACT FROM AUTHOR]

Focuses on the enzymatic synthesis of alpha'3sialylated and multiply alpha3fucosylated biantennary polylactosamines. Construction of novel polylactosamine glycans; Effects of glycans on l-selectin-dependent, lymphocyte-to-endothelium adhesion processes; Presence of fucose units on the sialylated LN units of the inhibitor saccharide.

Carbohydrate epitopes on cell surfaces are involved in various biological processes including cell–cell interactions, cell differentiation, cancer metastasis, and pathogen invasion. By blocking clinically relevant sugar receptors, synthetic carbohydrates have potential to become specific pharmaceuticals in various diseases. To achieve the necessary avidity, multivalent glycoconjugates have been constructed thus mimicking multivalent binding often adopted by cells and tissues. Here, we present methodology to create multivalent carbohydrate conjugates based on chondroitin and cyclodextrin carriers. Human milk tetrasaccharide LNnT was attached through a β-glycosylamide linkage to a chondroitin oligomer or an oxidized γ-cyclodextrin. In addition, a facile method was created to attach oligosaccharides to a cyclodextrin carrier using a linker including an oxime-linkage. [Copyright &y& Elsevier]