Carbohydrate oligosaccharides

Solid-phase organic synthesis (SPOS) is an established technique for generation of peptides,12 nucleotides,3 and more recently, carbohydrates (oligosaccharides).4-5 Supported syntheses of nonbiological oligomers6 16 and other small molecules17 21 have also been reported, reflecting the method s... 

Many proteins synthesized by the ribosomes of the RER contain short chains of carbohydrates (oligosaccharides) and are called glycoproteins. The oligosaccharides are of two main types O-linked (to the OH side chain of Ser or Thr) and N-linked (to the NH2 side chain of Asn). Some proteins are attached to the plasma membrane by a third type of carbohydrate structure called a glycosyl phosphatidylinositol (GPI) anchor. 

Some of the proteins and lipids on the external surface of the membrane contain short chains of carbohydrates (oligosaccharides) that extend into the aqneons medium. Carbohydrates therefore constitute 2 to 10% of the weight of plasma membranes. This hydrophilic carbohydrate layer, called the glycocalyx, protects the cell against digestion and restricts the nptake of hydrophobic componnds. 

Keywords Carbohydrates Oligosaccharides One-pot OptiMer Relative reactivity values Thioglycosides... 

There is a clear need for a specific labelling method for carbohydrates on heterogenous fibres. Antibodies can be used as specific markers for carbohydrates. Oligosaccharides derived from xylan by acid hydrolysis (10) and from xyloglucan by cellulase hydrolysis (//) have been used as antigens for production of polyclonal antibodies. Polymeric carbohydrates have also been used as antigens for antibody production (12-14). 

There are over 50 known glycosphingolipids based on the composition and sequence of the carbohydrate oligosaccharide. D-Galactocerebrosides are prevalent in the neuronal cell membranes of the brain (see Fig. 9.14B). Glucocerebrosides occur in the membranes of other nerve tissues. In many instances the carbohydrate moieties are oligosaccharides. A representative structure, known as lacto-cerebroside is shown in Fig. 9.14C. 

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