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 perf ormed the design of two beta-galactosidase derivatives with excellent activity and stability properties: i.e. a derivative of the enzyme fro m E. coli which is more than 1000-fold more stable than the soluble en zyme. These derivatives have allowed us to use drastic conditions (i.e . high concentration of orgaic cosolvents) for improving the specifici ty of our enzyme derivatives. In this way, by using these beta-galacto sidase derivatives as catalysts, we have been able to obtain very inte resting results in the enzymatic synthesis of several model disacchari des.