IMMOBILIZATION OF D-XYLOSE (D-GLUCOSE) ISOMERASE FROM A CHAINIA SPECIES

D-Xylose isomerase is a heat-stable enzyme which isomerizes D-xylose i nto D-xylulose. D-Xylose isomerase from various species also isomerize s D-glucose into D-fructose. This enzyme is used in industry for the p roduction of high-fructose corn syrup. The enzyme is specific for both , xylose and glucose. In most species xylose isomerase is localized in tracellularly. However, in a rare actinomycete, Chainia sp. (NCL 82-5- 1), xylose isomerase is present in both intracellular and extracellula r compartments. We have previously purified and characterized intracel lular enzyme from Chainia sp. In the present paper, we describe a proc edure for immobilization of intracellular xylose isomerase on INDION 4 8-R by ionic binding. This method is inexpensive, does not require cro ss-linking agents and results in firm binding of the enzyme with the r esin. The properties of immobilized enzyme such as pH optimum, substra te specificity, Km and inhibition by various metabolites are described and compared with those of purified, nonimmobilized enzyme.