SYNTHESES OF PHARMACEUTICAL OLIGOSACCHARIDES CATALYZED BY IMMOBILIZED-STABILIZED DERIVATIVES OF DIFFERENT BETA-GALACTOSIDASES

We have developed strategies for immobilizing and stabilizing enzymes with very different and complex structures. As an example we have performed the design of two beta-galactosidase derivatives with excellent activity and stability properties: i.e. a derivative of the enzyme from E. coli which is more than 1000-fold more stable than the soluble enzyme. These derivatives have allowed us to use drastic conditions (i.e. high concentration of orgaic cosolvents) for improving the specificity of our enzyme derivatives. In this way, by using these beta-galactosidase derivatives as catalysts, we have been able to obtain very interesting results in the enzymatic synthesis of several model disaccharides.