The effect of low oxygen tension on the activity of aerobic dehydrogenases

1952 ◽  
Vol 140 (899) ◽  
pp. 230-243 ◽  
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Substrate Concentration ◽  
Substrate Oxidation ◽  
Acid Oxidase ◽  
Low Oxygen ◽  
Michaelis Constant ◽  
Amino Acid Oxidase ◽  
Low Oxygen Tension ◽  
Primary Substrate

The oxidation of D-alanine, hypoxanthine and glucose by D-amino-acid oxidase, xanthine oxidase and glucose oxidase (notatin) respectively has been studied at O 2 tensions varying from 1 to 100 %, mainly with a view to examining enzyme activity at an O 2 tension comparable to that obtaining in the animal body, i.e. < 10 % O 2 . It was found that ( a ) the rate of substrate oxidation decreases markedly at O 2 tensions < 20 % , i.e. the enzymes examined have a low O 2 affinity; ( b ) the substrate concentration giving half-maximal oxidation rate (= Michaelis constant, K m ) decreases with a lowering of the O 2 tension; ( c ) the rate of primary substrate oxidation at low O 2 tension in presence of catalase is higher than in presence of catalase and a secondary substrate which undergoes peroxidatic oxidation by catalase and H 2 O 2 . A possible mechanism underlying this effect, which involves the participation of catalase and H 2 O 2 in primary substrate oxidation at low O 2 tension, is suggested.

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.

D-Serine metabolism: new insights into the modulation of D-amino acid oxidase activity

2013 ◽  
Vol 41 (6) ◽  
pp. 1551-1556 ◽  
Author(s):  
Silvia Sacchi
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Oxidase Activity ◽  
Acid Oxidase ◽  
Endogenous Ligand ◽  
Amino Acid Oxidase ◽  
The Brain ◽  
Serine Metabolism ◽  
Synthesis And Degradation

Over the years, accumulating evidence has indicated that D-serine represents the main endogenous ligand of NMDA (N-methyl-D-aspartate) receptors. In the brain, the concentration of D-serine stored in cells is defined by the activity of two enzymes: serine racemase (responsible for both the synthesis and degradation) and D-amino acid oxidase (which catalyses D-serine degradation). The present review is focused on human D-amino acid oxidase, discussing the mechanisms involved in modulating enzyme activity and stability, with the aim to substantiate the pivotal role of D-amino acid oxidase in brain D-serine metabolism.

scholarly journals d-aspartate oxidase in rat, bovine and sheep kidney cortex is localized in peroxisomes

1989 ◽  
Vol 261 (1) ◽  
pp. 233-238 ◽  
Author(s):  
K Zaar ◽  
A Völkl ◽  
H D Fahimi
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Matrix Protein ◽  
Subcellular Fractionation ◽  
Matrix Proteins ◽  
Kidney Cortex ◽  
Acid Oxidase ◽  
Marker Enzymes ◽  
Freezing And Thawing ◽  
Amino Acid Oxidase

D-Aspartate oxidase (EC 1.4.3.1) was assayed in subcellular fractions and in highly purified peroxisomes from rat, bovine and sheep kidney cortex as well as from rat liver. During all steps of subcellular-fractionation procedures, D-aspartate oxidase co-fractionated with peroxisomal marker enzymes. In highly purified preparations of peroxisomes, the enrichment of D-aspartate oxidase activity over the homogenate is about 32-fold, being comparable with that of the peroxisomal marker enzymes catalase and D-amino acid oxidase. Disruption of the peroxisomes by freezing and thawing released more than 90% of the enzyme activity, which is typical for soluble peroxisomal-matrix proteins. Our findings provide strong evidence that in these tissues D-aspartate oxidase is a peroxisomal-matrix protein and should be added as an additional flavoprotein oxidase to the known set of peroxisomal oxidases.

MOUSE MUTANT DEFICIENT IN d-AMINO ACID OXIDASE ACTIVITY

Genetics ◽  
1983 ◽  
Vol 103 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Ryuichi Konno ◽  
Yosihiro Yasumura
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Oxidase Activity ◽  
Null Allele ◽  
Gene Dosage ◽  
Autosomal Gene ◽  
Acid Oxidase ◽  
Wild Type ◽  
Amino Acid Oxidase ◽  
Gene Dosage Effect

ABSTRACT d-Amino acid oxidase activity in the kidney homogenates of mice of seven strains was measured to search for a mutant for this enzyme. There was a consistent sex difference in the enzyme activity in these strains: male mice showed higher levels of the enzyme activity than females. In contrast to other strains, some mice of the ddY strain did not possess enzyme activity. This trait was inheritable, and a mouse stock without enzyme activity (DAO-) was established. The allele (Dao-1c) carried by the DAO- mice was recessive and behaved as a single autosomal gene in inheritance. Heterozygous mice for this gene (Dao-1  +/Dao-1c) showed nearly half the enzyme activity of the wild-type homozygotes (Dao-1  +/Dao-1  +), suggesting that Dao-1c is a null allele and that there is a gene dosage effect on the enzyme activity.

Optimization of medium and cultivation conditions forl-amino acid oxidase production byAspergillus fumigatus

2009 ◽  
Vol 55 (9) ◽  
pp. 1096-1102 ◽  
Author(s):  
Susmita Singh ◽  
B. K. Gogoi ◽  
R. L. Bezbaruah
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Cell Mass ◽  
Industrial Applications ◽  
High Yield ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
North East ◽  
The North ◽  
Dry Cell

A fungal strain was selected from the microbial repository of the North-East Institute of Science and Technology, Jorhat, India, which could produce a high yield of l-amino acid oxidase. 18SrRNA, ITS1, 5.8SrRNA ITS2, and partial 28 S rRNA sequencing and phenotypic characteristics indicate that it belong to the species Aspergillus fumigatus (designated as P13). Maximum production of enzyme (59.55 × 10−3 U/mg dry cell mass) was obtained in a medium containing 10 g/L glucose, 4 g/L yeast extract, and 4 g/L ammonium sulfate, with 20 mmol/L of l-threonine as the inducer. The optimum temperature for enzyme production was 30 °C at pH 7.0, with a shaking speed of 200 r/min. At 96 h, the enzyme activity was maximum. The A. fumigatus P13 l-amino acid oxidase accepts a broad substrate range, and the maximum enzyme activity (20.41 × 10−3 U/mg dry cell mass) was obtained with 50 mmol/L of dl-tyrosine. In the literature, no reports have been found regarding the production of l-amino acid oxidase by A. fumigatus. The enzyme showed enantiomerically pure amino acid formation, which has tremendous demand in industrial applications.

Role of Castration and Androgens in D-Amino Acid Oxidase Activity of Tissues

1956 ◽  
Vol 185 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Barbara R. Endahl ◽  
Charles D. Kochakian
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Guinea Pig ◽  
Oxidase Activity ◽  
The Other ◽  
Maximum Effect ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Small Doses

A large number of C19 steroids were able to markedly increase the d-amino acid oxidase activity of the kidney of the castrated mouse. The maximum effect was attained within 21 days of treatment and with relatively small doses of the most potent androgens. On the other hand, neither castration nor various androgens were able to significantly alter the d-amino acid oxidase activity of either the kidney or liver of the castrated rat and guinea pig. Furthermore, age did not influence the enzyme activity of the tissues of the rat (2–8 months of age) or the guinea pig (4–8 months of age). Estradiol produced a small increase in the d-amino acid oxidase activity of the kidney of the mouse but estrone, methoxybisdehydrodiosynolic acid and several corticoids were ineffective.

scholarly journals Development of a Combination Fermentation Strategy to Simultaneously Increase Biomass and Enzyme Activity of D-amino acid Oxidase Expressed in Escherichia Coli

2021 ◽  
Author(s):  
Jian-Miao Xu ◽  
Hui-Ting Cao ◽  
Ming Wang ◽  
Bao-Jian Ma ◽  
Liu-Yu Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enzyme Activity ◽  
Amino Acid ◽  
Fermentation Process ◽  
Scale Up ◽  
Host Cells ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Dry Cell Weight ◽  
Fermentation Strategy

Abstract d-amino acid oxidase (DAAO) is widely used in the industrial preparation of l-amino acids, and cultivating Escherichia coli (E. coli) expressing DAAO for the biosynthesis of l-phosphinothricin (l-PPT) is very attractive. At present, the biomass production of DAAO by fermentation is still limited in large-scale industrial applications because the expression of DAAO during the fermentation process inhibits the growth of host cells, which limits higher cell density. In this study, the factors that inhibit the growth of bacterial cells during a 5 L fed-batch fermentation process were explored, and the fermentation process was optimized by co-expressing catalase (CAT), by balancing the biomass and the enzyme activity, and by adding exogenous d-alanine (d-Ala) to relieve the limitation of DAAO on the cells and optimize fermentation. Under optimal conditions, the DO-STAT feeding mode with DO controlled at 30% ± 5% and the addition of 27.5 g/L lactose mixed with 2 g/L d-Ala during induction at 28 °C resulted in the production of 26.03 g dry cell weight (DCW)/L biomass and 390.0 U/g DCW specific activity of DAAO; an increase of 78% and 84%, respectively, compared with the initial fermentation conditions. The fermentation strategy was successfully scale-up to a 5000L fermenter.

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