Cofactor regeneration in immobilized enzyme systems: chemical grafting of functional NAD in the active site of dehydrogenases.

One of the limiting steps in the further development of enzyme technology is the regeneration of cofactors, especially the pyridinic nucleotide cofactors. Immobilization of alcohol dehydrogenase and steroid dehydrogenase is described. In the last case stabilized enzymes could work in non aqueous solvents. Co-enzyme molecules are bound in the immediate vicinity of the active site of the enzyme. Cofactor regeneration was performed with an electron carrier (Phenazine methosulfate). Ageing phenomena were observed. The co-immobilization of superoxide dismutase gives rise to an increase of stability.