title: Purification and characterization of a novel (S)-enantioselective transaminase from Pseudomonas fluorescens KNK08-18 for the synthesis of optically active amines.
abstract: Pseudomonas fluorescens KNK08-18, showing (S)-selective transaminase activity, was isolated from soil by an enrichment culture method using (S)-7-methoxy-2-aminotetraline as the main nitrogen source. A transaminase was purified from the strain to homogeneity in seven steps. The relative mass of the enzyme was estimated to be 53 kDa on SDS-polyacrylamide gel electrophoresis and 120 kDa by gel filtration, suggesting a homodimeric structure. The optimal pH and temperature for enzyme activity were about 8.0-8.5 and 40 °C. The purified enzyme produced (S)-7-methoxy-2-aminotetraline, (S)-SMA, from 7-methoxy-2-tetralone (SMT) with high enantioselectivity. Although (S)-1-phenylethylamine was the best amino donor, β-alanine and 4-aminobutyric acid, which are good substrates for typical ω-amino acid transaminase (EC 2.6.1.18) and GABA transaminase (2.6.1.19), were not reacted. It aminated a broad range of carbonyl compounds containing aromatic, non-aromatic, and acidic and non-acidic substrates.
authors: Frontier Biochemical and Medical Research Laboratories, Kaneka Corporation, Takasago, Jyogo, Japan. Noriyuki.Ito@kaneka.co.jp
authors: Noriyuki
authors: N
authors: Ito
authors: Shigeru
authors: S
authors: Kawano
authors: Junzo
authors: J
authors: Hasegawa
authors: Yoshihiko
authors: Y
authors: Yasohara
mesh_terms: D000612:4-Aminobutyrate Transaminase / Q000737:chemistry*; D000588:Amines / Q000138:chemical synthesis*; D011551:Pseudomonas fluorescens / Q000201:enzymology*; D012988:Soil Microbiology; D013237:Stereoisomerism; D013379:Substrate Specificity; D013696:Temperature; D013764:Tetrahydronaphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D044024:Tetralones / Q000737:chemistry*; D000637:Transaminases / Q000737:chemistry* / Q000302:isolation & purification; D005680:gamma-Aminobutyric Acid / Q000737:chemistry
chemical_list: C570729:(S)-7-methoxy-2-aminotetraline; C570728:7-methoxy-2-tetralone; D000588:Amines; D013764:Tetrahydronaphthalenes; D044024:Tetralones; D005680:gamma-Aminobutyric Acid; D000637:Transaminases; D000612:4-Aminobutyrate Transaminase