Glycans surface

As part of a study on cell-surface glycans, 2,3-bis(tetradecyloxy)propyl 2-deoxy-2-fluoro-a- and - -D-mannopyranosides were prepared by condensation of 3,4,6-tri-0-benzyl-2-deoxy-2-fluoro-a-D-mannopyranosyl chloride with 2,3-bis(tetradecyloxy)propanol. 

Cancer Increased branching of cell surface glycans or presentation of selectin ligands may be important in metastasis. 

Glycophorins A, B, and C are also transmembrane glycoproteins but of the single-pass type, extending across the membrane only once. A is the major gly-cophorin, is made up of 131 amino acids, and is heavily glycosylated (about 60% of its mass). Its amino terminal end, which contains 16 oligosaccharide chains (15 of which are O-glycans), extrudes out from the surface of... 

Chang PV, Prescher JA, Hangauer MJ, Bertozzi CR (2007) Imaging cell surface glycans with bioorthogonal chemical reporters. J Am Chem Soc 129 8400-8401... 

To label cell-surface azide-glycans, the cells are reacted for 1 hour using a final concentration of 1 mM biotin-PEG-phosphine reagent dissolved in PBS, pH 7.4. 

The biotinylated glycans on the cell surfaces subsequently may be probed with (strept)avidin reagents to detect the azido-sialic acid modifications. Alternatively, the cells may be lysed and the glycoproteins isolated using an immobilized (strept)avidin or monomeric avidin affinity resin. 

A congener of the GPI membrane anchor, present on the cell surface of the malaria pathogen Plasmodium falciparum 127, was also tackled. The molecule is composed of one inositol moiety (I) and four monosaccharide units (II-V) [80]. The retrosynth-esis identified a single NPOE retron 108 as the precursor for all glycan units (Scheme 5.28). Transformations of the latter afforded NPOE analogs 128, 89,... 

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