title: Production of chiral β-amino acids using ω-transaminase from Burkholderia graminis.
abstract: Optically pure β-amino acids are of high pharmacological significance since they are used as key ingredients in many physiologically active compounds. Despite a number of enzymatic routes to these compounds, an efficient synthesis of β-amino acids continues to pose a major challenge for researchers. ω-Transaminase has emerged as an important class of enzymes for generating amine compounds. However, only a few ω-transaminases have been reported so far which show activity towards aromatic β-amino acids. In this study, (S)-ω-transaminase from Burkholderia graminis C4D1M has been functionally characterized and used for the production of chiral aromatic β-amino acids via kinetic resolution. The enzyme showed a specific activity of 3.1 U/mg towards rac-β-phenylalanine at 37°C. The Km and Kcat values of this enzyme towards rac-β-phenylalanine with pyruvate as the amino acceptor were 2.88 mM and 91.57 min(-1) respectively. Using this enzyme, racemic β-amino acids were kinetically resolved to produce (R)-β-amino acids with an excellent enantiomeric excess (> 99%) and ∼ 50% conversion. Additionally, kinetic resolution of aromatic β-amino acids was performed using benzaldehyde as a cheap amino acceptor.
authors.affiliation: School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, South Korea.
authors.forename: Sam
authors.initials: S
authors.lastname: Mathew
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea.
authors.forename: Hanseop
authors.initials: H
authors.lastname: Bea
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea.
authors.forename: Saravanan Prabhu
authors.initials: SP
authors.lastname: Nadarajan
authors.affiliation: School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, South Korea.
authors.forename: Taeowan
authors.initials: T
authors.lastname: Chung
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea. Electronic address: hyungdon@konkuk.ac.kr.
authors.forename: Hyungdon
authors.initials: H
authors.lastname: Yun
mesh_terms: D024322:Amino Acids, Aromatic / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001547:Benzaldehydes / Q000737:chemistry*; D019117:Burkholderia / Q000145:classification / Q000201:enzymology*; D020134:Catalytic Domain; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D010802:Phylogeny; D013379:Substrate Specificity; D013696:Temperature; D000637:Transaminases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D024322:Amino Acids, Aromatic; D001426:Bacterial Proteins; D001547:Benzaldehydes; D000637:Transaminases; C032175:benzaldehyde
keywords: Biocatalysis; Kinetic resolution; Unnatural amino acid; β-Amino acids; ω-Transaminase