Limited Proteolysis and X-ray Crystallography Reveal the Origin of Substrate Specificity and of the Rate-Limiting Product Release during Oxidation ofd-Amino Acids Catalyzed by Mammaliand-Amino Acid Oxidase†,‡

Biochemistry ◽  
1997 ◽  
Vol 36 (19) ◽  
pp. 5624-5632 ◽  
Author(s):  
Maria A. Vanoni ◽  
Antonio Cosma ◽  
Daniela Mazzeo ◽  
Andrea Mattevi ◽  
Flavia Todone ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Limited Proteolysis ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
X Ray ◽  
Product Release ◽  
X Ray Crystallography ◽  
Rate Limiting

scholarly journals Amino Acid Catabolism by an areA-Regulated Gene Encoding an l-Amino Acid Oxidase with Broad Substrate Specificity in Aspergillus nidulans

2005 ◽  
Vol 71 (7) ◽  
pp. 3551-3555 ◽  
Author(s):  
Meryl A. Davis ◽  
Marion C. Askin ◽  
Michael J. Hynes
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Nitrogen Sources ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Broad Substrate Specificity ◽  
Strong Growth

ABSTRACT The filamentous fungus Aspergillus nidulans can use a wide range of compounds as nitrogen sources. The synthesis of the various catabolic enzymes needed to breakdown these nitrogen sources is regulated by the areA gene, which encodes a GATA transcription factor required to activate gene expression under nitrogen-limiting conditions. The areA102 mutation results in pleiotropic effects on nitrogen source utilization, including better growth on certain amino acids as nitrogen sources. Mutations in the sarA gene were previously isolated as suppressors of the strong growth of an areA102 strain on l-histidine as a sole nitrogen source. We cloned the sarA gene by complementation of a sarA mutant and showed that it encodes an l-amino acid oxidase enzyme with broad substrate specificity. Elevated expression of this enzyme activity in an areA102 background accounts for the strong growth of these strains on amino acids that are substrates for this enzyme. Loss of function sarA mutations, which abolish the l-amino acid oxidase activity, reverse the areA102 phenotype. Growth tests with areA102 and sarA mutants show that this enzyme is the primary route of catabolism for some amino acids, while other amino acids are metabolized through alternative pathways that yield either ammonium or glutamate for growth.

scholarly journals Biological role of D-amino acid oxidase and D-aspartate oxidase. Effects of D-amino acids.

1993 ◽  
Vol 268 (36) ◽  
pp. 26941-26949
Author(s):  
A D'Aniello ◽  
G D'Onofrio ◽  
M Pischetola ◽  
G D'Aniello ◽  
A Vetere ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Biological Role ◽  
Acid Oxidase ◽  
Amino Acid Oxidase

scholarly journals Localization of D-amino acid oxidase on the cell surface of human polymorphonuclear leukocytes

1978 ◽  
Vol 77 (1) ◽  
pp. 59-71 ◽  
Author(s):  
JM Robinson ◽  
RT Briggs ◽  
MJ Karnovsky
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cell Surface ◽  
Polymorphonuclear Leukocytes ◽  
Ultrastructural Localization ◽  
H2o2 Production ◽  
Acid Oxidase ◽  
Resting Cells ◽  
Amino Acid Oxidase ◽  
Human Polymorphonuclear Leukocytes

The ultrastructural localization of D-amino acid oxidase (DAO) was studied cytochemically by detecting sites of hydrogen peroxide production in human polymorphonuclear leukocytes (PMNs). Reaction product, which forms when cerous ions react with H2O2 to form an electron-dense precipitate, was demonstrated on the cell surface and within the phagosomes of phagocytically stimulated cells when D-amino acids were provided as substrate. Resting cells showed only slight activity. The competitive inhibitor D,L-2-hydroxybutyrate greatly reduced the D-amino acid-stimulated reaction while KCN did not. The cell surface reaction was abolished by nonpenetrating inhibitors of enzyme activity while that within the phagosome was not eliminated. Dense accumulations of reaction product were formed in cells which phagocytosed Staphylococcus aureus in the absence of exogenous substrate. No reaction product formed with Proteus vulgaris while an intermediate amount formed when Escherichia coli were phagocytosed. Variation in the amount of reaction product with the different bacteria correlated with the levels of D-amino acids in the bacterial cell walls which are available for the DAO of PMNs. An alternative approach utilizing ferricyanide as an electron acceptor was also used. This technique verified the results obtained with the cerium reaction, i.e., the DAO is located in the cell surface and is internalized during phagocytosis and is capable of H2O2 production within the phagosome. The present finding that DAO is localized on the cell surface further supports the concept that the plasma membrane is involved in peroxide formation in PMNs.

Production ofD-amino acid oxidase byAspergillussp. strain O20 active on cephalosporin C

1997 ◽  
Vol 43 (3) ◽  
pp. 292-295 ◽  
Author(s):  
Salim K. Mujawar ◽  
Jaiprakash G. Shewale
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Amino Acid ◽  
Stationary Growth Phase ◽  
Acid Oxidase ◽  
Cephalosporin C ◽  
Production Medium ◽  
Stationary Growth ◽  
Amino Acid Oxidase ◽  
Aspergillus Sp

Aspergillus sp. strain O20 produces inducible D-amino acid oxidase intracellularly, only in the presence of some amino acids. The enzyme was induced most effectively by the addition of DL-alanine (1% w/v) to the production medium. Among the various compounds studied, production of the D-amino acid oxidase was enhanced by Aerosol-22, glucose, and sodium nitrate. D-Amino acid oxidase formation was observed during the onset of the stationary growth phase. Maximum enzyme activity was recorded after 96 h of fermentation (1000 IU/L).Key words: D-amino acid oxidase, Aspergillus sp., 7-aminocephalosporanic acid, cephalosporin C.

An Automated Detection System for Most L-α-Amino Acids

1969 ◽  
Vol 15 (2) ◽  
pp. 154-161 ◽  
Author(s):  
K Van Dyke ◽  
C Szustkiewicz
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Detection System ◽  
Automated System ◽  
Acid Oxidase ◽  
Enzymatic Reactions ◽  
Amino Acid Oxidase ◽  
Automated Method ◽  
Wide Range

Abstract An automated system for the determination of the L-α form of the majority of amino acids is presented. The method is based upon oxidative deamination of the amino acid coupled with oxidation of o-dianisidine by hydrogen peroxide. This procedure can be used comparatively for the determination of a mixture of L-α-amino acids or for the majority of separated L-α-amino acids (especially in conjunction with column separations from urine and blood which give falsely positive identification with ninhydrin detection). The stereospecific nature of the L-α-amino acid oxidase enables the investigator to quantitate the amount of L-α-amino acid in the presence of the D-α form. From an academic viewpoint, the extreme sensitivity and wide range of the detection system make it advantageous for the study of the enzyme itself. This automated method also may be employed to follow enzymatic reactions—e.g., those catalyzed by peptidases or racemases. The methodology is extremely convenient with good reagent stability and is much more sensitive than manometric technics.

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