title: Biochemical characterization of thermostable ω-transaminase from Sphaerobacter thermophilus and its application for producing aromatic β- and γ-amino acids.
abstract: An (S)-ω-transaminase from the thermophilic eubacterium Sphaerobacter thermophilus was expressed and functionally characterized. The enzyme showed good stability at high temperature and in the presence of various substrates. Substrate specificity analysis showed that the enzyme had activity towards a broad range of substrates including amines, β- and γ-amino acids. The purified enzyme showed a specific activity of 3.3U/mg towards rac-β-phenylalanine at 37°C. The applicability of this enzyme as an attractive biocatalyst was demonstrated by synthesizing optically pure β- and γ-amino acids. Among the various beta and gamma amino acids produced via asymmetric synthesis, (S)-4-amino-4-(4-methoxyphenyl)-butanoic acid showed highest analytical yield (82%) with excellent enantiomeric excess (>99%).
authors.affiliation: School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, South Korea.
authors.forename: Sam
authors.initials: S
authors.lastname: Mathew
authors.affiliation: Department Bioscience & Biotechnology, Konkuk University, Seoul 143-701, South Korea.
authors.forename: Saravanan Prabhu
authors.initials: SP
authors.lastname: Nadarajan
authors.affiliation: School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, South Korea.
authors.forename: Taeowan
authors.initials: T
authors.lastname: Chung
authors.affiliation: School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, South Korea.
authors.forename: Hyun Ho
authors.initials: HH
authors.lastname: Park
authors.affiliation: Department Bioscience & Biotechnology, Konkuk University, Seoul 143-701, South Korea. Electronic address: hyungdon@konkuk.ac.kr.
authors.forename: Hyungdon
authors.initials: H
authors.lastname: Yun
mesh_terms: D019943:Amino Acid Substitution; D024322:Amino Acids, Aromatic / Q000096:biosynthesis* / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D055162:Biocatalysis; D020134:Catalytic Domain / Q000235:genetics; D041862:Chloroflexi / Q000201:enzymology* / Q000235:genetics; D004795:Enzyme Stability; D005798:Genes, Bacterial; D007700:Kinetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D013237:Stereoisomerism; D013379:Substrate Specificity; D013696:Temperature; D000637:Transaminases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D024322:Amino Acids, Aromatic; D001426:Bacterial Proteins; D000637:Transaminases
keywords: Asymmetric synthesis; Beta amino acid; Gamma amino acid; Kinetic resolution; Thermostable enzyme; ω-Transaminase