title: Novel phenylalanine dehydrogenases from Sporosarcina ureae and Bacillus sphaericus. Purification and characterization.
abstract: NAD+-dependent phenylalanine dehydrogenases were purified 1,500- and 1,600-fold, and crystallized from Sporosarcina ureae SCRC-R04 and Bacillus sphaericus SCRC-R79a, respectively. The purified enzymes were homogeneous as judged by disc gel electrophoresis. The enzyme from S. ureae has a molecular weight of 305,000, while that of B. sphaericus has a molecular weight of 340,000. Each is probably composed of eight subunits identical in molecular weight. The S. ureae enzyme showed a high substrate specificity in the oxidative deamination reaction acting on L-phenylalanine, while that of B. sphaericus acted on L-phenylalanine and L-tyrosine. The enzymes had lower substrate specificities in the reductive amination reaction acting on alpha-keto acids. The Sporosarcina enzyme acted on phenylpyruvate, alpha-ketocaproate, alpha-keto-gamma-methylthiobutyrate and rho-hydroxyphenylpyruvate. The Bacillus enzyme acted on rho-hydroxyphenylpyruvate, phenylpyruvate, and alpha-keto-gamma-methylthiobutyrate. The enzyme from B. sphaericus catalyzes The enzyme from B. sphaericus catalyzes the transfer of pro-S (B) hydrogen from NADH.
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000302:isolation & purification*; D001406:Bacillaceae / Q000201:enzymology*; D001407:Bacillus / Q000201:enzymology*; D003460:Crystallization; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005779:Immunodiffusion; D007526:Isoelectric Point; D046911:Macromolecular Substances; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D013379:Substrate Specificity
chemical_list: D004791:Enzyme Inhibitors; D046911:Macromolecular Substances; D008670:Metals; D000594:Amino Acid Oxidoreductases; C022342:phenylalanine oxidase