[Prostaglandin-H-synthase: stability and activity during immobilization on silica gel].

: Prostaglandin H synthase was isolated in the form of microsomes from sheep vesicular glands and immobilized on silica gel. This system of prostaglandin synthesis was activated by calcium ions and stabilized by adrenaline. Microsomes immobilized in the presence of adrenaline and calcium ions were stable upon storage at 4 degrees C. After two months, their activity was 80% of the initial activity. Immobilized microsomes were able to catalyze several cycles of prostaglandin E2 synthesis with no substantial loss of activity: after eight utilization cycles, they retained 66% of their initial enzymic activity.