Cell surface glycans

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. 

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

Ogawa, T, Sugimoto, M, Kitajima, T, Sadozai, K K, Nukada, T, Synthetic studies on cell surface glycans. 51. Total synthesis of an undecasaccharide. A t)fpical carbohydrate sequence for the complex type of glycan chains of a glycoprotein. Tetrahedron Lett., 27, 5739-5742, 1986. 

Fig. 10.3-16 Introduction of unnatural functional groups through posttranslational modification, (a) Ketones and azides can be introduced onto cell surfaces by feeding cells with unnatural sialic acid precursors, such as mannosamine derivatives 40b and c. These are incorporated into cell-surface glycans, which can be further elaborated using additional bioconjugation reactions, (b) Specific amino acid sequences can be modified using biotin ligase. Interestingly, ketobiotin" is also recognized as a substrate for the enzyme, allowing a...

T. Ogawa, S. Nakabayashi, and S. Shibata, Synthetic studies on cell surface glycans. Part XVIII. Synthetic studies on nephritogenic glycosides. Synthesis of Al-(P-L-aspartyl)-a-D-glucopyranosylamine, Agr. Biol. Chem., 47 (1983) 281-285. 

Matsuzaki Y, Ito Y, Nakahara Y, Ogawa T. Synthetic studies on cell-surface glycans. 93. Synthesis of branched poly-N-acetyUactosamine type pentaan-tennary pentacosasaccharide glycan part of a glycosyl ceramide from rabbit erythrocyte membrane. Tetrahedron Lett 1993 34 1061-1064. 

LPPG b the major cell surface glycan of epimasdgote with approximately 1.5x10 copies per cell. LPPG can be considered a member of the GPI family based on the presence of the Man(al,4)GlcN(al,Q g r-inositol-l-P04-lipid modf, the hallmark of all GPI anchors. 

Notes 1. Sialic acid has an uncon romising role in v tebrates as it is often at the capping position of cell surface glycan and is therefore exposed for interactions with exo nous cells and proteins. Sialic acid is a critical component of glycan epitopes responsible for initiating inflammatory leukocyte adhesion, B-ceU signaling and activation and viral binding. 

Beyond its utility in elaborating cell surface glycan structures, chemical tagging of azide-labeled glycan via phosphine ligation permits the identification/purification of specific glycoproteins subtypes for proteomic and glycomic studies. 

Incorporation of 9-AAz-NeuAc into cell surface glycans allows In situ photo-affinity crosslinking of CD22 to cis glycoprotein ligands... 

Incorporation of 9-BPC-NeuAc into cell surface glycans modulates CD22-ligand binding affinity in situ... 

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