以环氧乙烷为活性基的多孔颗粒状固定化青霉素酰化酶的制备

报道了用以环氧乙烷为活性基的多孔颗粒状载体（Eupergit-C）制备固定由巨大芽孢杆菌（B．megaterium）产生的青霉素酰化酶的研究。用已二胺，赖氨酸对载体进行化学修饰后制备固定化酶，获得了较好的固定结果。用未修饰的载体制备固化酶，经24h固定反应，酶活力达176．5IU／g（wet），酶活力总叫率达53．7％，酶蛋白的固定量为19＝7mg/g（dr），酶蛋白的固定效率达87．5％。游离酶的酶浓度对制备固定化酶的活力无显影响。当加酶量从312IU/g（dry）上升到6250IU／g（dry）时，固定化酶活力从89IU／g(wet）上升到475IU／g（wet），总收率和固定化效率分别从99％和99％下降到26．5％和32．5％，酶蛋白的固定量从6．9mg/g（dry）上升到112mg/g（dry），酶蛋白的固定效率从99％下降至80．5％。以酶活力为155IU/g(wet），酶蛋白固定量为22mg/g(dry）的固定化酶水解青霉素G钾盐，经过20批循环水解后，剩余酶活力为92．5％。

EMMOBILZATION STUDIES OF PENICILLIN ACYLASE ON THE POROUS BEAD WITH OXIRANE GROUPS

Penicillin Acylase from B. megaterium was immobilized on the porous bead carriers based on methacrylate, N,N-methelene-bis-methacrymide, glycidyl methacrylate, Allyl ether copolymers (Eupergit-c) either directly or after chemical modification with 1.6-deaminohexane and L-Lysine. Directly binding with oxirane groups, the most efficient immobilization results were achieved. The immobilization yield was markedly influenced by the ratio of amount of free enzyme to the weight of the carrier. The specific activities of 89 up to 475IU/g (wet) and binding protein of 6.9 to 112 mg/g (dry) were obtained when the free enzyme added to the immobilization solution was from 323IU/g (dry) up to 6250IU/g (dry). The residual activity of immobilized PGA in a recycling system at the 20th was about 92.5% of the initial value.