酶法合成L-4-甲砜基苯丙氨酸

以4-甲砜基苯丙酮酸和L-天冬氨酸为底物, 利用重组大肠杆菌DM204(pGEX-KG-aspC/BL21)表达的天冬氨酸转氨酶酶法转化得到了L-4-甲砜基苯丙氨酸, 优化得到的酶法最佳转化条件为: 转化温度37 ℃, 反应体系pH=8, 底物4-甲砜基苯丙酮酸质量分数8%, 质量分数0.6%的吐温80和10-4 mol/L Mg2+对酶活有促进作用. 在最佳工艺条件下经过12 h酶促反应, 4-甲砜基苯丙酮酸摩尔转化率达95%. 本研究利用化学生物法制备了L-4-甲砜基苯丙氨酸, 为制备其它天然氨基酸衍生物提供了新思路.

Enzymatic Synthesis of L-4-Methylsulphonyl-phenylalanine

L-Phenylalanine derivatives are key components or intermediates of many anti-tumor compounds. L-4-Methylsulfonyl-phenylalanine may inhibit tumor cell proliferation. At present, L-phenylalanine derivatives are normally produced by chemical resolution or enzymatic method. In this work, the chiral compound L-4-methylsulphonyl-phenylalanine was prepared by enzymatic method from 4-methylsulphonyl-phenylpyruvate and L-aspartic acid. The influence of various factors on the biocatalysis was studied. The optimal temperature and pH value were 37 ℃ and 8. The optimal mass fraction of 4-methylsulphonyl-phenylpyruvate and tween 80 were 8% and 0.6%. 1×10-4 mol/L of Mg2+ can improve the activity of aspartate aminotransferase. Under the optimal conditions, bioconversion rate of 4-methylsulphonyl-phenylpyruvate reached 95% after 12 h. The study provides a new idea for preparing L-phenylalanine derivatives.