Carbohydrate recognition processes

Levitzki A (2000) Protein Tyrosine Kinase Inhibitors as Therapeutic Agents. 211 1-15 Li G, Gouzy M-F, Fuhrhop J-H (2002) Recognition Processes with Amphiphilic Carbohydrates in Water. 218 133-158 Li X, see Paldus J (1999) 203 1-20... 

Carbohydrate conformation plays a key role for molecular recognition processes, and their determination contributes to the understanding of many biological processes. The latest NMR methodological developments for conformation determination are discussed here, and representative examples are given. 

Carbohydrates not only act as ligands, but they can also provide scaffolds for molecular recognition processes. It is well known that cyclodextrins (CDs) are able to form an inclusion complex with specific guest molecules. In the last years, NMR experiments combined with other techniques have been used to highlight different recognition events. 

In principle, mass spectrometry is not suitable to differentiate enantiomers. However, mass spectrometry is able to distinguish between diastereomers and has been applied to stereochemical problems in different areas of chemistry. In the field of chiral cluster chemistry, mass spectrometry, sometimes in combination with chiral chromatography, has been extensively applied to studies of proton- and metal-bound clusters, self-recognition processes, cyclodextrin and crown ethers inclusion complexes, carbohydrate complexes, and others. Several excellent reviews on this topic are nowadays available. A survey of the most relevant examples will be given in this section. Most of the studies was based on ion abundance analysis, often coupled with MIKE and CID ion fragmentation on MS " and FT-ICR mass spectrometric instruments, using Cl, MALDI, FAB, and ESI, and atmospheric pressure ionization (API) methods. 

Multivalent protein-carbohydrate interactions mediate many intercellular recognition processes. In order to study and to modulate multivalent protein-carbohydrate interactions, many carbohydrate-functionalized frameworks and systems have been synthesized. The glycodendrimer is one important glycosystem that has been used to study lectin binding. For our work, glycodendrimers based on the PAMAM framework are ideal because of the inherently flexible nature of PAMAM and because of the ease with which PAMAMs can be functionalized with carbohydrates. 

Reuter, G. Gabius, H.-J. (1999) Eukaryotic glycosylation whim of nature or multipurpose tool Cell. Mol. Life Sci. 55, 368-422. Excellent review of the chemical diversity of oligosaccharides and polysaccharides and of biological processes dependent upon protein-carbohydrate recognition. 

We have mentioned earlier that sugars can serve as signal molecules in a biological system and can interact with water (chapter IV). We describe here the possible role carbohydrates in general can play in recognition process and can respond to a homeopathic potency. Carbohydrates with bound water molecules play an important role in recognition process. Potentized homeopathic drugs, which are essentially structured water molecules, initiate specific biochemical events in cells when they come in contact with carbohydrate molecules. 

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