酶法拆分N-乙酰-D,L-蛋氨酸转化条件优化

摘要

重组大肠杆菌BL21/pET22b-argE表达的N-乙酰鸟氨酸脱酰基酶(NAOase)可用于脂肪族氨基酸的手性拆分.水解N-乙酰-D,L-氨基酸中的L-型底物,N-乙酰-D,L-蛋氨酸为其最合适的底物.为了确定NAOase拆分N-乙酰-D,L-蛋氨酸合适的转化条件,考察了反应温度、pH值、Co~(2+)浓度、转化时间、底物浓度和加酶量对产物的影响.结果表明,合适的反应条件为37℃,pH值7.0,Co~(2+) 1 mmol/L,转化时间20 min,底物浓度150 mmol/L,菌泥5 g/L.在上述反应条件下,N-乙酰-D,L-蛋氨酸的转化率可达81.4%.%N-acety-L-ornithine deacetylase (NAOase) expressed by recombinant engineering strain BL21/pET22b-arg-E can be used to separate chiral aliphatic amino acids, and its optimal substrate is N-acetyl- D,L -methionine. In order to obtain the appropriate conversion conditions of N-acetyl- D,L -methionine by NAOase, the effects of temperature, pH, concentration of Co~(2+), concentration of substrate and enzyme dosage on conversion of N-acetyl- D, L -methionine were investigated. The results showed that the conversion of N-acetyl- D,L -methionine was 81. 4% under the appropriate conditions of 37℃ , pH7. 0, concentration of Co~(2+) 1 mmol/L, reaction time 20 min, concentration of substrate 150 mmol/L and enzyme 5 g/L.