精氨酸酶转化生产D-精氨酸和L-鸟氨酸

Production of D-Arginine and L-Ornithine by Enzymatic Conversion of L-Arginine Amidinase

摘要:

以L-精氨酸为原料，经水杨醛催化消旋反应得到DL-精氨酸，在精氨酸酶的作用下，定向地将L-精氨酸转化为L-鸟氨酸和尿素，并经过进一步分离纯化得到D-精氨酸和L-鸟氨酸盐酸盐。本文通过水杨醛对L-精氨酸进行消旋化，反应2.5 h消旋率可以达到75%；同时对L-精氨酸酶促反应条件进行了优化，实验结果表明，最佳反应条件为：37 ℃， pH=10， 反应时间24 h，底物浓度40 g/L，酶浓度0.2 g/L，转化率可达98%。经此法制备得到的产物D-精氨酸和L-鸟氨酸盐酸盐纯化后光学纯度可达99%。

Abstract:

A practical method for the racemization of L-arginine and an enzymatic method for optical resolution of DL-arginine by L-arginine amidinase have been developed. We obtained D-arginine and L-ornithine hydrochloride after isolation and purification. Many factors affected the racemization and enzymatic reaction. The whole process of racemization by this method can be completed within 2.5 h. The ratio of the racemization was as high as 74.5%. The result shows that the optimum conditions of enzymatic reaction were: 35 ℃, pH=10, c( DL-arginine) = 40 g/L and c(L-arginine amidinase) = 0.2 g/L. The conversion rate of L-arginine was higher than 98%. The products were separated and purified on ion-exchange resin. The optical purity of products were 99%.