Immobilization of Isochorismate Hydroxymutase. Comparison of Native Versus Immobilized Enzyme

Abstract

Partially purified isochorismate hydroxymutase (isochorismate synthase, E.C. 5.4.99.6) from Flavobacterium K3-15, a vitamin K overproducer, was immobilized on CNBr-activated Sepharose 4B, alkylamine glass substituted with glutardialdehyde, and aminohexyl Sepharose 4B substituted with glutardialdehyde. The immobilized enzyme exhibited a lower specific activity but a broader pH tolerance and a higher thermostability than the soluble enzyme. The stability of the enzyme was greatly increased by immobilization. Isochorismic acid, which is not commercially available, was prepared by a constant flow incubation.