Enzymatic properties and application of L-asparaginase–collagen membrane

The activity of the L -asparaginase–collagen membrane was 3.4 U/mg membrane (5.8 U/cm² membrane) and the activity yield was 29%. The apparent Michaelis constant of the asparaginase–collagen membrane was 5.9 × 10^?3M. The operational half-life of the immobilized asparaginase column was 35–40 days. The L -asparaginase–collagen membrane retained 90% of its original activity after ethylene oxide gas sterilization. The dried membrane stored at room temperature retained its original activity for five months, and the membrane stored in 0.05M phosphate buffer (pH 8.0) retained its original activity for one week at 37°C. The L -asparaginase–collagen membrane tanned with 1% glutaraldehyde was stable against proteolytic enzymes. Complete degradation of L -asparagine by the L -asparaginase–collagen membrane occurred at a low concentration. The L -asparagine in dog blood plasma was completely degraded within 20 min by the extracorporal shunt using the L -asparaginase–collagen membrane.