2504-83-8Relevant articles and documents
Kinetics of Oxidation of Amino Acids by Alkaline Hexacyanoferrate(III)
Laloo, Didcy,Mahanti, Mahendra K.
, p. 311 - 313 (1990)
The kinetics of oxidation of amino acids (lysine, arginine, and histidine) by alkaline hexacyanoferrate(III) has been studied at constant ionic strength over the temperature range 318-338 K.The rate was dependent on the first powers of the concentrations of substrate and oxidant, but independent of the concentration of the alkali in the range studied.The reaction proceeds by way of the α-imino acid, formed in a rapid step, which then undergoes hydrolysis to give the corresponding α-keto acid.
A new l-arginine oxidase engineered from l-glutamate oxidase
Yano, Yoshika,Matsuo, Shinsaku,Ito, Nanako,Tamura, Takashi,Kusakabe, Hitoshi,Inagaki, Kenji,Imada, Katsumi
, p. 1044 - 1055 (2021/04/14)
The alternation of substrate specificity expands the application range of enzymes in industrial, medical, and pharmaceutical fields. l-Glutamate oxidase (LGOX) from Streptomyces sp. X-119-6 catalyzes the oxidative deamination of l-glutamate to produce 2-ketoglutarate with ammonia and hydrogen peroxide. LGOX shows strict substrate specificity for l-glutamate. Previous studies on LGOX revealed that Arg305 in its active site recognizes the side chain of l-glutamate, and replacement of Arg305 by other amino acids drastically changes the substrate specificity of LGOX. Here we demonstrate that the R305E mutant variant of LGOX exhibits strict specificity for l-arginine. The oxidative deamination activity of LGOX to l-arginine is higher than that of l-arginine oxidase form from Pseudomonas sp. TPU 7192. X-ray crystal structure analysis revealed that the guanidino group of l-arginine is recognized not only by Glu305 but also Asp433, Trp564, and Glu617, which interact with Arg305 in wild-type LGOX. Multiple interactions by these residues provide strict specificity and high activity of LGOX R305E toward l-arginine. LGOX R305E is a thermostable and pH stable enzyme. The amount of hydrogen peroxide, which is a byproduct of oxidative deamination of l-arginine by LGOX R305E, is proportional to the concentration of l-arginine in a range from 0 to 100 μM. The linear relationship is maintained around 1 μM of l-arginine. Thus, LGOX R305E is suitable for the determination of l-arginine.
Characterization of d-amino acid aminotransferase from Lactobacillus salivarius
Kobayashi, Jyumpei,Shimizu, Yasuhiro,Mutaguchi, Yuta,Doi, Katsumi,Ohshima, Toshihisa
, p. 15 - 22 (2013/10/22)
We searched a UniProt database of lactic acid bacteria in an effort to identify d-amino acid metabolizing enzymes other than alanine racemase. We found a d-amino acid aminotransferase (d-AAT) homologous gene (UniProt ID: Q1WRM6) in the genome of Lactobacillus salivarius. The gene was then expressed in Escherichia coli, and its product exhibited transaminase activity between d-alanine and α-ketoglutarate. This is the first characterization of a d-AAT from a lactic acid bacterium. L. salivarius d-AAT is a homodimer that uses pyridoxal-5′-phosphate (PLP) as a cofactor; it contains 0.91 molecules of PLP per subunit. Maximum activity was seen at a temperature of 60 °C and a pH of 6.0. However, the enzyme lost no activity when incubated for 30 min at 30 °C and pH 5.5 to 9.5, and retained half its activity when incubated at pH 4.5 or 11.0 under the same conditions. Double reciprocal plots of the initial velocity and d-alanine concentrations in the presence of several fixed concentrations of α-ketoglutarate gave a series of parallel lines, which is consistent with a Ping-Pong mechanism. The Km values for d-alanine and α-ketoglutarate were 1.05 and 3.78 mM, respectively. With this enzyme, d-allo-isoleucine exhibited greater relative activity than d-alanine as the amino donor, while α-ketobutylate, glyoxylate and indole-3-pyruvate were all more preferable amino acceptors than α-ketoglutarate. The substrate specificity of L. salivarius d-AAT thus differs greatly from those of the other d-AATs so far reported.
Role of the active site residues arginine-216 and arginine-237 in the substrate specificity of mammalian D-aspartate oxidase
Katane, Masumi,Saitoh, Yasuaki,Maeda, Kazuhiro,Hanai, Toshihiko,Sekine, Masae,Furuchi, Takemitsu,Homma, Hiroshi
experimental part, p. 467 - 476 (2011/10/05)
d-Aspartate oxidase (DDO) and d-amino acid oxidase (DAO) are flavin adenine dinucleotide-containing flavoproteins that catalyze the oxidative deamination of d-amino acids. Unlike DAO, which acts on several neutral and basic d-amino acids, DDO is highly specific for acidic d-amino acids. Based on molecular modeling and simulated annealing docking analyses, a recombinant mouse DDO carrying two substitutions (Arg-216 to Leu and Arg-237 to Tyr) was generated (R216L-R237Y variant). This variant and two previously constructed single-point mutants of mouse DDO (R216L and R237Y variants) were characterized to investigate the role of Arg-216 and Arg-237 in the substrate specificity of mouse DDO. The R216L-R237Y and R216L variants acquired a broad specificity for several neutral and basic d-amino acids, and showed a considerable decrease in activity against acidic d-amino acids. The R237Y variant, however, did not show any additional specificity for neutral or basic d-amino acids and its activity against acidic d-amino acids was greatly reduced. The kinetic properties of these variants indicated that the Arg-216 residue is important for the catalytic activity and substrate specificity of mouse DDO. However, Arg-237 is, apparently, only marginally involved in substrate recognition, but is important for catalytic activity. Notably, the substrate specificity of the R216L-R237Y variant differed significantly from that of the R216L variant, suggesting that Arg-237 has subsidiary effects on substrate specificity. Additional experiments using several DDO and DAO inhibitors also suggested the involvement of Arg-216 in the substrate specificity and catalytic activity of mouse DDO and that Arg-237 is possibly involved in substrate recognition by this enzyme. Collectively, these results indicate that Arg-216 and Arg-237 play crucial and subsidiary role(s), respectively, in the substrate specificity of mouse DDO.
