Publisher's Synopsis
This volume reviews the unlimited possibilities that appear to be opening up as a result of developments in glycotechnology and the physiological significance of endoglycosidases leading to new avenues in the field. Endoglycosidases are one of the general types of glycosidases and hydrolyze internal glycosidic bonds of oligosaccharide and polysaccharide chains, resulting in the release not of monosaccharides, but oligosaccharides. On the other hand, exoglycosidases (which act on nonreducing end sites of carbohydrate chains and as a result release a monosaccharide) corresponding to al most all of the glycosidic bonds of the known carbohydrate chains of glycocon- gates have been discovered. Some endoglycosidases, for example, amylase, cellulase and hyaluronidase, were previously known. However, except for hyaluronidase, the endoglycosidases which act on a long carbohydrate chain of glycoconjugates (glycoproteins, gly- lipids and proteoglycans) have not been investigated. The original enzymes for the inborn error of metabolism on the carbohydrate chains of glycoconjugates are exoglycosidases and related enzymes on the degra dation processes of carbohydrate chains, and the mechanism of glycoconjugate metabolism is explained by the exoglycosidases. Therefore, there was little or no awareness of the many kinds of endoglycosidases that exist. In order to elucidate the degradation mechanism of glycoconjugates, the uri nary carbohydrates were examined, resulting in the identification of many kinds of oligosaccharides and polysaccharides which are free from amino acids and pep tides. Thus it was suggested that many kinds of endoglycosidases which act on in ternal sites of carbohydrate chains exist in the animal body.
