Popis: |
A packing material for size-exclusion chromatography, Toyopearl, which was derivatized by introducing amino groups, was found to be a good support for the immobilization of urease. The immobilized enzyme had an optimum pH of 7, the same value as for intact urease. In the use of the enzyme, packed in PTFE tubing (ca. 8 cm × 0.7 mm I.D.) in a flow system, the addition of ethylenediaminetetraacetic acid (EDTA) to the eluent was found to be essential. With phosphate buffers containing EDTA, a constant high value of the enzyme activity could be obtained for 21 days at 37°C. |