Transaminase-catalyzed asymmetric synthesis of L-2-aminobutyric acid from achiral reactants.
Asymmetric synthesis of an unnatural amino acid was demonstrated by omega-transaminase from Vibrio fluvialis JS17. L-2-Aminobutyric acid was synthesized from 2-oxobutyric acid and benzylamine with an enantiomeric excess higher than 99%. The reaction showed severe product inhibition by benzaldehyde, which was overcome by employing a biphasic reaction system to remove the inhibitory product from the aqueous phase. In a typical biphasic reaction (50 mM 2-oxobutyric acid, 70 mM benzylamine and 2.64 U/ml purified enzyme) using hexane as an extractant, conversion of 2-oxobutyric acid reached 96% in 5 h whereas only 39% conversion was obtained without the product extraction.
Shin
Jong-Shik
JS
Department of Biotechnology, Yonsei University, Shinchon-Dong 134, Seodaemun-Gu, Seoul, 120-749, South Korea. enzymo@yonsei.ac.kr
Kim
Byung-Gee
BG
D000613:Aminobutyrates / Q000378:metabolism*; D001547:Benzaldehydes / Q000494:pharmacology; D001596:Benzylamines / Q000378:metabolism; D002087:Butyrates / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D013237:Stereoisomerism; D000637:Transaminases / Q000378:metabolism*; D014733:Vibrio / Q000201:enzymology*
D000613:Aminobutyrates; D001547:Benzaldehydes; D001596:Benzylamines; D002087:Butyrates; D004791:Enzyme Inhibitors; C005087:alpha-ketobutyric acid; C012223:alpha-aminobutyric acid; C030796:benzylamine; D000637:Transaminases; C032175:benzaldehyde