固定化苯丙氨酸脱氨酶拆分D,L苯丙氨酸制备D苯丙氨酸
Chiral resolution of D, L- phenylalanineusing immobilized phenylalanine ammonia- lyase for production of D- phenylalanine
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摘要: 为了建立新的D-苯丙氨酸生产工艺,对固定化苯丙氨酸解氨酶（PAL）拆分D,L-苯丙氨酸进行了研究。以介孔材料（MCM-41）为载体固定PAL,将其用于拆分消旋体D,L-苯丙氨酸制备高光学纯的D-苯丙氨酸。最佳的固定化条件是载酶量为50mg/g、壳聚糖浓度为0.1%（w/v）、戊二醛浓度为0.05%（v/v）,固定化酶的活性达到最大,酶活保留达到92%,重复利用20次后,活性仍能保持85%。将制备的固定化酶应用于D,L-苯丙氨酸的拆分,反应24h L-苯丙氨酸转化率达到98%,D-苯丙氨酸的ee值达到96%,且连续拆分10个批次后固定化酶对L-苯丙氨酸的转化率仍保持在95%以上。因此,高效稳定的固定化PAL在拆分D,L-苯丙氨酸生产D-苯丙氨酸中具有良好的应用前景。Abstract: In order to establish a new method for the production of D- phenylalanine, the chiral resolution of D, L- phenylalanine using immobilized phenylalanine ammonia lyase ( PAL) was investigated. The mesoporous silica materials MCM-41 was used as support. Under the optical immobilization conditions, a maximum activity of PAL was 92% of the free enzyme.The reusability of immobilized enzyme retained 85% activity after 20 cycles.Using the immobilized PAL to catalyze resolution of D, L- phenylalanine, a 98% conversion ratio of L- phenylalanine was attained within 24 h, and the enantiomeric excess value of D- phenylalanine attained 96%. The immobilization enzyme ran continuously for 10 batches, the conversion ratio retained above 95%. Therefore, the immobilized PAL showed commercial application for the production of D- phenylalanine from chiral resolution of D, L- phenylalanine.
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