Properties of free and immobilized glucose isomerase

Abstract

In recent years, a considerable amount of work has been carried out on immobilized enzymes [l-4] , but relatively few studies are concerned with the immobilization of glucose isomerase (D-xylose ketol-isomerase EC 5.3.1.5) [5,6] . Glucose isomerase (GI) was entrapped in polyacrylamide gel [5] and covalently bound to porous glass [6], but poor results were obtained for the instability and the low activity of these preparations. The present communication describes the properties of the glucose isomerase from Sfrepfomyces griseolus as free and immobilized form. A new method of immobilization [7], consisting in the physical entrapment of proteins in filamentous structures, was used to prepare insoluble derivatives of glucose isomerase. Optimal conditions for enzyme stability and activity in free and immobilized form are reported.