title: A novel transaminase, (R)-amine:pyruvate aminotransferase, from Arthrobacter sp. KNK168 (FERM BP-5228): purification, characterization, and gene cloning.
abstract: A novel (R)-amine transaminase, which catalyzed (R)-enantioselective transamination of chiral amine, was purified to homogeneity from Arthrobacter sp. KNK168 (FERM BP-5228). The molecular mass of the enzyme was estimated to be 148 kDa by gel filtration and 37 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis, suggesting a homotetrameric structure. The enzyme catalyzed transamination between amines and pyruvate stereo-specifically. The reaction on 1-methylbenzylamine was (R)-enantioselective. Pyruvate was the best amino acceptor, but the enzyme showed broad amino acceptor specificity for various ketone and aldehyde compounds. The apparent K(m)s for (R)-1-methylbenzylamine and pyruvate were 2.62 and 2.29 mM, respectively. The cloned gene of the enzyme consists of an open reading frame (ORF) of 993 bp encoding a protein of 330 amino acids, with a calculated molecular weight of 36,288. The deduced amino acid sequence was found to be homologous to those of the aminotransferases belonging to fold class IV of pyridoxal-5'-phosphate-dependent enzymes, such as branched-chain amino acid aminotransferases.
authors: QOL Division Technology Management Department Research Group, Kaneka Corporation, Takasago, Hyogo, Japan. Akira_Iwasaki@kn.kaneka.co.jp
authors: Akira
authors: A
authors: Iwasaki
authors: Keiji
authors: K
authors: Matsumoto
authors: Junzo
authors: J
authors: Hasegawa
authors: Yoshihiko
authors: Y
authors: Yasohara
mesh_terms: D000588:Amines / Q000378:metabolism*; D000595:Amino Acid Sequence; D001173:Arthrobacter / Q000201:enzymology* / Q000235:genetics*; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D055503:Protein Multimerization; D019289:Pyruvic Acid / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature; D000637:Transaminases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000588:Amines; D004269:DNA, Bacterial; D019289:Pyruvic Acid; D000637:Transaminases; C022341:phenylalanine (histidine) aminotransferase