【摘要】 研究了青霉素G酰化酶(PGA)在含环氧活性基的多孔高聚物载体上的固定化及修饰,优化固定化条件为1 mol/L,pH 8.0的磷酸钾缓冲体系,每克载体(湿重)投酶量为500~550 U,30℃下150 r/min固定化36~48 h,得到的固定化酶表观酶活为每克载体(湿重)177 U,表观酶活回收率35%。固定化酶经巯基乙醇修饰后提高了热稳定性。固定化酶水解青霉素G的最适pH为9.0,最适温度为47℃,在pH 4~9,40℃以下稳定。固定化酶的各项性能均优于游离酶。更多还原

【Abstract】 Penicillin G acylase(PGA) was immobilized on a kind of oxirane carrier and modified by mercaptoethanol after immobilization,which improved thermal stabilization of immobilized PGA(IPA).The optimum condition of immobilization reaction was 1 mol/L phosphate potassium buffer of pH 8.0,(addition) enzyme on wet carrier between 500~550 U/g,and shaking gently(150 r/min) for 36~48 h at (30 ℃).The apparent activity of the immobilized enzyme on wet carrier prepared under these conditions was 177 U/g and the apparent activity recovery was 35%.The optimal pH and temperature of immobilized PGA were 9.0 and 47 ℃ for hydrolysis of penicillin G respectively.The immobilized enzyme was stable in the range of pH 4~9 and at the temperature below 40 ℃.Compared with free PGA,IPA was eximious on most enzymatic characterizations.更多还原