Stabilitaet und Reaktivitaet immobilisierter Enzyme in organischen Loesungsmitteln Abschlussbericht

The usage of organic solvents in enzyme reactions opens completely new perspectives to the application of enzyme catalysis. Therefore, it has attracted increasing attention in the recent research of enzymology. The present project is, on the one hand, concerned with phospholipase D, which is expected to allow the synthesis of new interesting phospholipids because of its transphosphatidylation potency. It was shown that phospholipase D is capable of exchanging the choline residue in lecithin for other OH-containing compounds (ethanolamine, glycerol, etc.), if it is used in immobilized form and in water-poor solvents such as diethyl ether/3% water. For immobilization, the enzyme was preferably bound to polymers containing long-chain aliphatic spacers. Furthermore, the interplay of reversible/irreversible denaturation and changes in the catalytic parameters of enzymes in organic solvents, which has not been sufficiently comprehended so far, was studied. Soluble and immobilized glucoamylase (A. niger) in water-miscible organic solvents was used as a model system. The results show that catalytic and stability behaviour are influenced in different way. (orig.)SIGLEAvailable from TIB Hannover: DtF QN1(29,24) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman