earticle

영어

In this study, (R)-3-fluoroalanine was asymmetrically synthesized from 3-fluoropyruvate (F-pyruvate) and (S)-a-methylbenzylamine (MBA) using recombinant w-transaminase (TA) from Vibrio fluvialis JS17.
The reaction was severely inhibited by acetophenone (deaminated product of a-MBA). In the presence of 5 mM acetophenone, the reactivity of the enzyme towards F-pyruvate decreased by 22 %. To overcome product inhibition by acetophenone, a biphasic reaction was successfully used. The conversion of F-pyruvate into (R)-3-fluoroalanine (enatiomeric exess (e.e.) >99%) was about 95% in the biphasic system (75 mM F-pyruvate, 100 mM (S)-a-MBA, and 3.0 U/ml), whereas only 31% was obtained without product extraction. The use of racemic a-MBA as an amino donor instead of (S)-a-MBA can not only reduce the reaction cost but can also produce chiral amines by kinetic resolution. When the kinetic resolution of racemic a-MBA (40 mM) was carried out with F-pyruvate (30 mM) and w-TA(3.0 U/ml) in 100 mM phosphate buffer (pH 7.0), the e.e. of (R)-■a-MBA reached 98.4% with a 52.2% conversion for 10 h and 21 mM (R)-3-fluoroalanine was produced with a 70 % conversion and an e.e. >99 %. }