Carbohydrate-recognizing

Both hemagglutinin and sialidase are carbohydrate-recognizing proteins and in humans recognize the well-known sialic acid, A-acetylneuraminic acid (Neu5Ac, 3), associated as the terminal carbohydrate unit of upper respiratory tract and lung-associated glycoconjugates.12,14... 

This observation has an analogy in the world of microbes, which need to adhere effectively to the surface of their host cells to escape the shear forces of body fluids. Bacteria utilize both protein-protein and carbohydrate-protein interactions for adhesion. Pathogenic Escherichia coli (E. coli) bacteria, for example, responsible for more than 80% of urinary tract infections [2], possess thin hair-like structures on their surfaces, called pili and the shorter fimbriae. Fimbriae specifically recognize carbohydrates. Type 1 fimbriae of E. coli, for example, can, via their FimH lectin domain [3], bind a-D-mannopyranosides. Lectins, e.g. [4-7] named after the Latin word legere to pick out or choose [8] are carbohydrate recognizing proteins found everywhere in nature, e.g. [9-13] and are intensively studied structures. 

Some pathogens nse carbohydrate recognizing lectins as a means of attachment to eukaryotic cell surfaces such as hemagglutinins of influenza and other virases. These... 

Neufeld, E., Ashwell, G. 1979. Carbohydrate recognizing systems for receptor-mediated pinocyto-sis. In Biochemistry of Glycoprotein and Proteoglycans, W. Lennarz, ed. Plenum Press, New York, pp. 241-266. 

Because carbohydrates usually have numerous chirality centers, it was recognized long ago that a quick method for representing carbohydrate stereochemistry is needed. In 1891, Emil Fischer suggested a method based on the projection of a tetrahedral carbon atom onto a flat surface. These Fischer projections were soon adopted and are now a standard means of representing stereochemistry at chirality centers, particularly in carbohydrate chemistry. 

Because sugars are involved in most of the mechanisms established for the synthesis of these heterocycles, the development of carbohydrate chemistry has been most helpful in these researches—especially for the preparation of specifically labeled molecules. Conversely, the contribution of these efforts to carbohydrate chemistry and biochemistry has shown the involvement in biosynthesis of 1 -deoxy-D-f/rreo-pentulose—scarcely before recognized and considered a rare sugar—and of fully functionalized pentuloses of still unknown configuration (or their phosphates). Finally, evidence has been found in prokaryotes for a most extraordinary transformation of 5-amino-l-(P-D-ribofuranosyl)imidazole 5 -phos-phate into a pyrimidine. Surely, this transformation should be explained in terms... 

GA is well recognized as emulsifier used in essential oil and flavor industries. Randall et al., 1998, reported that the AGP complex is the main component responsible for GA ability to stabilize emulsions, by the association of the AGP amphiphilic protein component with the surface of oil droplets, while the hydrophilic carbohydrate fraction is oriented toward the aqueous phase, preventing aggregation of the droplets by electrostatic repulsion. However, only 1-2% of the gum is absorbed into the oil-water interface and participates in the emulsification thus, over 12% of GA content is required to stabilize emulsions with 20%... 

Recently a phenomenon of resistance to biocide solutions has been recognized (see also Chapters 9 and 13) in which bacteria adhere to a container wall and cover themselves with a carbohydrate slime called a glycocalyx thus, doubly protected (wall and glycocalyx), they have been found to resist biocide attack. 

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