Properties of arginase immobilized in a fibrin clot.

Rat liver arginase was covalently trapped in a fibrin clot. Among the physicochemical properties of the enzyme studied were Mn2+ requirement, pH behavior, temperature and time stability, effect of denaturing agents, and kinetic properties. The immobilized arginase showed the same substrate affinity as soluble arginase, but had higher stability at room temperature, was more resistant to denaturation, and had a higher catalytic activity at physiological pH. The properties so far examined may enhance the use of immobilized arginase in cancer therapy.