Oligosaccharides clustering

K. Drickamer, and A.-C. Roche, Oligolysine-based oligosaccharide clusters selective recognition and endocytosis by the mannose receptor and dendritic cell-specific intercellular adhesion molecule 3 (ICAM-3)-grabbing nonintegrin, /. Biol. Chem., 278 (2003) 23922-23929. 

Borate diol ester linkage between apiose rings in oligosaccharide clusters of rhamnogalacturonan II in two pectin chains. 

Fig. 3.3. Schematic illustration of the proposed architecture of mucus glycoproteins, (a) Subunits constitute a linear array of oligosaccharide clusters interspersed with naked stretches of protein. (b) Trypsin digestion affords glycopeptides corresponding to the oligosaccharide clusters. (c) The whole mucins are formed by an end-to-end association of subunits via disulphide bonds, (d) The hydrodynamic model of mucus glycoproteins conforms to a random coil within a spheroidal solvent domain. (After Allen et al., 1984.)...

Monovalent and multivalent fluorescent probes can be utilized to evaluate the influence of oligosaccharide clustering on recognition by cell-surface lectins. Fluorescence microscopy and flow cytometry are appropriate methods to visualize the corresponding receptor-carbohydrate interactions. 

To better understand the critical role of oligosaccharide-receptor interactions and their molecular mechanisms through the cluster-effect, and thus access optimized synthetic ligands, several research groups have shown creativity in proposing original multivalent platforms that could allow for tailored valencies, dimensions, and epitope orientations. 

The trichloroacetimidate method has also been used to prepare bivalent Lex oligosaccharides to study the conformational details of carbohydrate clusters by NMR spectroscopy [437] TWo Le trisaccharides were covalently linked through... 

Systematic investigations of mannose-binding proteins with clustered mannosides other than natural multiantennary oligosaccharides have been rather scarce until recently. However, using 6 -0-phosphorylated mannose disaccharide scaffolded on peptide templates using combinatorial glycopeptide libraries. 

---