聚丙烯腈纤维固定化青霉素酰化酶性质的研究

STUDIES ON SOME PROPERTIES OF THE IMMOBILIZED PENICILLIN ACYLASE BY POLYACRYLONITRILE FIBRES

将巨大芽孢杆菌（Bacillusmegaterium）青霉素酞化酶连接到聚丙烯腈纤维载体上，制成固定化青霉素酰化酶。其表现活力约为2000u／g。水解青霉素G的最适温度为50℃；最适PH为9．0；在PHS．5～10．3、温度50℃以下酶的活力稳定；表观米氏常数Ka为1．33×10-8mol／L；最大反应速度Vm为2．564mmol·min-1；苯乙酸为竞争性抑制剂，抑制常数为0．16mol／L。水解10％的青霉素G钾盐溶液，使用20批，保留酶活力80％。

The extracellular penicillin acylase from Bacillus megaterium was immobilized by coupling tO derivatives of polyacrylonitrile fibres. The apparent activity of the immobilized penicillin acylase was about 2000 u / g (dry weight). The optimal pH and temperature were 9.0 and 50℃ for hydrolysis of penicillin G, respectively.The immobilized enzyme was stable in the pH range of 5.5～10.3, and at the temperature below 50℃. The apparent Michaelis constant Ka and Vm of the immobilization enzyme were 1.33 × 10-2 mol / L and 2.564 mmol·min-1 , respectively.The inhibition constant of phenylacetic acid acted as a competitive inhibitor for The immobilization enzyme was 0.16 mol / L. The remained activity was about 80% after operating 20 times.