Transglycosylation glycosidases

Reversed Hydrolysis vs. Transglycosylation. Glycosidases have been used for several years for the selective hydrolysis of carbohydrates, such as for the hydrolysis of starch and for the analysis of glycoconjugate carbohydrate structures. These enzymes also can be used for the regioselective and stereospecific synthesis of oligosaccharides in equilibrium-controlled (reversed-hydrolysis. Equation 1) or kinetically controlled (transglycosylation. Equation 2) reactions ... [Pg.52]

Transglycosylation with activated substrates and glycosidases has been reported in several applications on a 100-mg scale, but the yields achieved with these methods are low, and the need for solvent systems to dissolve pNP-sugars limits their utility.9 To... [Pg.103]

The structure of the leaving group is a decisive factor for donor properties. Natural substrates for glycosidases are polysaccharidic chains and the corresponding disaccharides are still used in transglycosylation reactions as... [Pg.317]

Figure 1. Reaction mechanism of retaining b-glycosidases. R aglycon group. R = H, hydrolysis. R = alcohol, transglycosylation.

The transfructosylation activity of this enzyme is strongly dependent on pH and the substrate concentration. Some glycosidases are known to be more hydrolytically active under acidic conditions, whereas their transglycosylation activity is higher at pH values above their pH optimum. Transfructosylation of... [Pg.51]

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