ABSTRACT
Saccharides are major constituents of the glycocalyx, playing an essential role in cell biology. This is well-known for the famous blood group antigens of red blood cells, all of them being carbohydrates. The biological significance of cell surface carbohydrates in cell communication unfolds in a highly complex interplay with other
Carbohydrate-Modifying Biocatalysts Edited by Peter Grunwald Copyright © 2012 Pan Stanford Publishing Pte. Ltd. www.panstanford.com
molecules, both membrane-anchored receptors and soluble molecules. There are secreted or membrane-bound proteins, which can recognize carbohydrates to form carbohydrate-protein complexes that are involved in cell development, the immune system, signal transduction, and also states of disease and malignancy. These proteins are called the lectins and occur ubiquitously in all organisms. Intracellular lectins frequently recognize core structures from glycoconjugate oligosaccharides, while cell surface and extracellular lectins often bind to terminal carbohydrate residues. The diversity of lectins, the molecular details of their interaction with glycans, the predominant multivalency effects occurring in carbohydrate-lectin interactions and the biological significance of carbohydrate-protein complex formation, including bacterial adhesion, are subject of this chapter.
