Cell surface carbohydrates, recognition with

One important area of current research is on the recognition of carbohydrates. In particular, cell surface carbohydrates have implications in various disease states. In some forms of cancer, closely packed cell surface carbohydrates effect cancer progression and invasiveness. Many of these carbohydrates have terminal sialic acid groups. The pinwheel receptor 42 was designed as a divalent receptor for anionic sugars including sialic acid with a view toward making sensors for cancer markers. Sensor 42 used a boronic acid to bind a diol on the... 

The continued interest in this field of study is reflected in the large number of review articles which have been published. The proceedings of an ICN-UCLA Symposium, in Colorado in 1977, have been published under the title Cell Surfaee Carbohydrates and Biological Recognition , and the proceedings of another symposium on cell membranes of normal and neoplastic cells has appeared as Cell Surface Carbohydrate Chemistry . Cell-surface antigens, with special reference to the histocompatibility antigens, have been reviewed. A comprehensive survey of the metabolism of cell-surface components in both eukaryotic and prokaryotic cells has been published. Other reviews have... 

The property of conformational restriction in polysaccharides make them candidates for being the initial self-ordering molecules of prebiotic evolution. This same property in the complex carbohydrate moiety of glycoproteins is the basis of carbohydrate-mediated information transfer through cell surface oligosaccharides interacting with each other or with lectin-like proteins in cell-cell recognition processes. 

The cell surface additionally displays receptors responsible for cell-cell recognition [28]. Members of this class of receptors are selectins [29] that recognize specific carbohydrates from other cells in the presence of calcium. Other cell surface receptors belong to the immunoglobulin superfamily (IgSF) [30] that promote calcium-independent cell-cell adhesion. The third important class are the calcium-dependent cell adhesion molecules, the cadherins [31], which form dimers with cadherin molecules presented on the surfaces of other cells and hence promote aggregation of similar cell types. 

The precise chemical interactions between an adhesin and its receptor are also important. For example, direct- and water-mediated hydrogen bonds are the most important interactions within the carbohydrate-recognition domain in carbohydrate-binding adhesins on the host cell surface (Weis and Drickamer, 1996). Nonpolar van der Waals interactions and hydrophobic "stacking of the receptor oligosaccharide rings with aromatic amino acid side chains of the bacterial adhesin protein also contribute to oligosaccharide-protein interactions. X-ray structural... 

---