Purification and partial characterization of N-hydroxy-l-phenylalanine decarboxylase/oxidase from Bacillus sp. strain OxB-1, an enzyme involved in aldoxime biosynthesis in the "aldoxime-nitrile pathway".
An enzyme that catalyzes the conversion of N-hydroxy-l-phenylalanine to phenylacetaldoxime was shown to be present in the Z-phenylacetaldoxime-degrading bacterium, Bacillus sp. strain OxB-1. The aldoxime-forming enzyme, which is induced by L-phenylalanine, was purified 8,050-fold to apparent homogeneity with a yield of 15.2%. The enzyme has a subunit M(r) of about 86,000. The enzyme converts N-hydroxy-L-phenylalanine (K(m) 0.99 mM) to only one geometrical isomer, namely Z-phenylacetaldoxime. Relatively large amounts of pyridoxal 5'-phosphate (PLP) are required to be present in the reaction mixture because PLP reacts non-enzymatically with the N-hydroxy amino acid substrate to form a nitrone. Several characteristics of the enzyme were compared with those of other PLP-dependent aromatic amino acid-converting enzymes described in the literature. The enzyme is tentatively named "N-hydroxy-L-phenylalanine decarboxylase/oxidase". Finally, the possible biosynthesis and metabolism of phenylacetaldoxime in Bacillus sp. strain OxB-1 is discussed.
Kato
Yasuo
Y
Biotechnology Research Center, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
Tsuda
Takashi
T
Asano
Yasuhisa
Y
D001407:Bacillus / Q000201:enzymology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry; D002262:Carboxy-Lyases / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D008970:Molecular Weight; D009570:Nitriles / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry; D010091:Oximes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011732:Pyridoxal Phosphate / Q000737:chemistry; D013379:Substrate Specificity; D013696:Temperature
D001426:Bacterial Proteins; D009570:Nitriles; D009589:Nitrogen Oxides; D010091:Oximes; D011108:Polymers; C015388:nitrones; D011732:Pyridoxal Phosphate; C408881:phenylacetaldoxime; C041725:butyl-Toyopearl 650; D002262:Carboxy-Lyases; C019517:phenylalanine decarboxylase