Studies on Dextranase. VIII. Some Enzymatic Properties of Immobilized Dextranase from Brevibacterium fuscum var. dextranlyticum

Abstract

Dextranase (EC 3.2.1.11) of Brevibacterium fuscum var. dextranlyticum was immobilized by the fixation to Sepharose 4B activated with cyanogen bromide. The specific activity of the preparation was about 30%, compared with that of native dextranase. The immobilization led to increase pH stability, although thermal stability, optimum pH and temperature were similar to that of the native enzyme, respectively. The immobilized dextranase was very stable on storage at 4° and retained more 90% of the initial activity in the 9th weeks whereas the native enzyme lost about 50% of it after 6 days later. Relative activity of immobilized dextranase on dextrans with various molecular weights decreased relatively for an increase in molecular weight. Michaelis constant (Km) of the immobilized enzyme was larger 2–5 times than that of the native enzyme on each molecular weight of dextran. Action pattern of dextranase was not effected by the immobilization. Immobilized dextranase was very stable in a column reaction and suitable for continuous enzyme reaction, and also found to keep steady activity by the repeated use. These properties of immobilized dextranase of B. fuscum were very similar to those of the immobilized enzyme of P. funiculosum. © 1975, The Pharmaceutical Society of Japan. All rights reserved.