利用重组大肠杆菌(E.coliBL21-pET/aspC)所产天冬氨酸转氨酶立体选择性地催化转化对氟苯丙酮酸(FPPA)生成L-4-氟苯丙氨酸(FPhe)。优化了转化条件,实验结果表明,最佳转化条件:温度37℃,pH值范围5.0-8.0,菌体用量为菌体与FPPA质量浓度比为5.5(菌龄8 h),吐温80的质量分数为0.6%,FPPA的质量浓度7.08 g/L,L-天冬氨酸与FPPA摩尔比为1.6。在最适条件下,经过12 h酶转化反应基本完成,FPPA转化率达到90%以上,FPhe得率达到85%以上,为FPhe的制备提供了一种新方法。
The chiral compound L-4-fluorophenylalanine (FPhe) was prepared by aspartate aminotransferase (Asp-AT) method. 4-fluorophenylpyruvate (FPPA) was converted to FPhe catalyzed by Asp-AT of recombinant E. coli B1221-pET/aspC. After 12 h enzymatic reaction, the of FPhe could be above 85 % under the following optimal bioconversion yield of FPPA was over 90% and the yield conditions as follows : 37 ℃, pH value range of 5.0-8.0, 5.5 of the mass ratio of cell to FPPA ( 8 h of strain age) , 0.6% of the mass fraction of Tween 80, 7.08 g/L of the FPPA mass concentration and 1.6 of mole ratio of L-Aspartate and FPPA. It provides a new method to prepare FPhe.