【摘要】 以构建的青霉素酰化酶基因工程菌(E.Coli 108/PPAHD 1)为材料,经硫酸铵沉淀、离子交换和制备电泳等手段将青霉素酰化酶的纯度提高了155倍,比活达17 u/mg,其凝胶电泳呈现单带。该酶有两个亚基,分子量分别为62300 d 和14900 d。并测定了该酶对温度及 pH 稳定范围、米氏常数等电点。更多还原

【Abstract】 Penicillin acylase from E.coli 108/PPAHD1 constructed byDNA recombinant technology has been purified to homogeneity successivelythrough ammonium sulfate fractionation,ion exchange chromatography andpreparative PAGE.The purity of the enzyme has been increased 155 times.Thespecific activity of the enzyme is 17u/mg.The enzyme has two subunits withmolecular weight estimated by SDS PAGE of 62300d and 14900d respectively,The enzyme is stable below 50℃ and at pH 5.0～8.0;the optimum temperature45℃ and optimum pH 7.5;the Michaelis constant for NIPAB 1.54×10^-6;andisoelectric points 6.2 and 6.6.更多还原