新型固定化青霉素酰化酶的动力学性质

The Kinetics of A Novel Immobilized Penicillin Acylase

研究了自行研制的新型固定化青霉素酰化酶的动力学性质。结果表明,该固定化青霉素酰化酶与自由酶相比,具有较宽的pH和温度适应范围,最适pH和温度分别为8.6和50℃;酶促反应的最适底物浓度为3%;表观米氏常数K_m=0.0325 mol/L;最大酶促反应速度v_m=1.083 mmol/(g.min);高浓度的底物对反应存在有底物抑制效应,底物抑制常数K_s=0.0812 mol/L;苯乙酸和★★★★★★★★★★★6-APA的抑制常数K_((?)PAA)、K_((?)APA分别为0.0132 mol/L、0.00869 mol/L。

In this paper,kinetics of a novel immobilized penicillin acylase was studied. The carriers were polymerized with vinylacetate in suspension and penicillin acylase was coupled on the carriers activited with p-penzoquinone. The results showed that activity of immobilized enzyme changed less than free enzyme when pH and temperature varied. The optimum pH and temperature were 8.6 and 50 ℃ respectively. The optimum concentration was 3%. The Michaelis-Menten constant(Km) and maximized reaction velocity(V_m) were 0.0325 mol/L and 1.083 mmol/(g·min), respectively. It was also found that substrate and product including PAA and 6-APA could inhibit the catalyze recation, K_s=0.0812 mol/ L, K_(i,pAA)=0.0132 mol/L, K_(i,APA)=0.00869 mol/L.