Purification and characterization of kynurenine-2-oxoglutarate aminotransferase from the liver, brain and small intestine of rats

Noguchi, T.; Minatogawa, Yohsuke; Okuno, Etsuo; Nakatani, Masaki; Morimoto, M

doi:10.1042/bj1510399

Cited by 49 publications

(22 citation statements)

References 23 publications

(19 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent reports have shown that several enzymes catalyze the transamination of L-KYN and various 2-oxo-Baran/Staniek/Kepplinger/Gille/Stolze/ Nohl acids to KYNA in various tissues [18][19][20] and the CNS [18][19][20][21][22]. The enzymes kynurenine aminotransferases (KATs) have been identified and characterized in several organs [18][19][20][21][22].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Kynurenic Acid Influences the Respiratory Parameters of Rat Heart Mitochondria

et al. 2001

View full text Add to dashboard Cite

In the present study the effect of L-kynurenine, kynurenic acid and quinolinic acid on the heart mitochondrial function were investigated. Mitochondria were incubated with saturating concentrations of respiratory substrates glutamate/malate (5 mmol/l), succinate (10 mmol/l) or NADH (1 mmol/l), with and without kynurenines. The concentration of kynurenines varied between 1.25 µmol/l and 10 mmol/l. From all investigated kynurenines, only kynurenic acid affected dose-dependently the respiratory parameters of heart mitochondria. Respiratory control and P/O values were reduced significantly with glutamate/malate and moderately with succinate as substrates in the presence of 125 µmol/l to 10 mmol/l kynurenic acid. A known elevation of L-kynurenine in the blood of patients with ischemic heart disease or essential hypertension may suggest the involvement of L-kynurenine metabolites in the impairment of heart mitochondrial function, for example in cardiomyopathy.

show abstract

Section: Discussionmentioning

confidence: 99%

“…The enzymes kynurenine aminotransferases (KATs) have been identified and characterized in several organs [18][19][20][21][22]. It is known that some of the transaminases are localized in the inner membrane of mitochondria [16].…”

Section: Discussionmentioning

confidence: 99%

Kynurenic Acid Influences the Respiratory Parameters of Rat Heart Mitochondria

et al. 2001

View full text Add to dashboard Cite

show abstract

“…These observations suggest that the transamination of the three amino acids is catalysed by a single enzyme. Recently, we reported that isoenzyme 1 is identical with the mitochondrial aspartate 2-oxoglutarate aminotransferase, and also with the mitochondrial tyrosine 2-oxoglutarate aminotransferase, suggesting that the transamination of kynurenine by this enzyme does not function in the physiological condition [27,28] i<h e apparent^ values of the purified isoenzyme 3 for kynurenine was lower than thosel 29 ' 30 ! of isoenzymes 1 and 2.…”

Section: Discussionmentioning

confidence: 88%

Identity of Kynurenine: Pyruvate Aminotransferase with Histidine:Pyruvate Aminotransferase

Noguchi¹,

Kido²

1976

Hoppe-Seyler´s Zeitschrift für physiologische Chemie

View full text Add to dashboard Cite

Kynurenine pyruvate aminotransferase was purified from rat kidney. The purified enzyme had an isoelectric point of pH 5.2 and a pH optimum of 9.3. The enzyme was active with pyruvate as amino acceptor but not with 2-oxoglutarate, and utilized various aromatic amino acids as amino donors. L-Amino acids were effective in the following order of activity: histidine > phenylalanine > kynurenine > tyrosine > tryptophan > 5-hydroxytryptophan. The apparent K m values were about 0.63mM, 1.4mM and 0.09mM for histidine, kynurenine and phenylalanine, respectively. K m values for pyruvate were 5.5mM with histidine as amino donor, 1.3mM with kynurenine and 8.5mM with phenylalanine. Kynurenine pyruvate aminotransferase activity of the enzyme was inhibited by the addition of histidine or phenylalanine. The molecular weights determined by gel filtration and sucrose density gradient centrifugation were approximately 76000 and 79000, respectively. On the basis of purification ratio, substrate specificity, inhibition by common substrates, subcellular distribution, isoelectric focusing and polyacrylamide-gel electrophoresis, it is suggested that kynurenine pyruvate aminotransferase is identical with histidine pyruvate aminotransferase and also with phenylalanine pyruvate aminotransferase. The physiological significance of the enzyme is discussed.

show abstract

“…The occurrence of KYNA has been confirmed practically in all brain cells, in the digestive system, peripheral blood, saliva and in organs such as the heart and liver, but the level of this acid in healthy individuals is relatively low (Noguchi et al . ; Turski et al . ; Baran et al .…”

Section: Introductionmentioning

confidence: 99%

“…In humans, the endogenous level of KYNA in the brain may change in pathologic conditions as Alzheimer's disease, schizophrenia or Parkinson's disease (Ogawa et al 1992; Baran, Jellinger & Deecke 1999;Erhardt et al 2001). The occurrence of KYNA has been confirmed practically in all brain cells, in the digestive system, peripheral blood, saliva and in organs such as the heart and liver, but the level of this acid in healthy individuals is relatively low (Noguchi et al 1975;Turski et al 1988; Baran et al 1997;Amirkhani et al 2002). Its concentration, however, rises to the micromolar level in inflammatory conditions or infections.…”

Section: Introductionmentioning

confidence: 99%

Effect of feed supplementation with kynurenic acid on the morphology of the liver, kidney and gills in rainbow trout (Oncorhynchus mykiss Walbaum, 1792), healthy and experimentally infected with Yersinia ruckeri

Kaczorek

Szarek

Mikiewicz

et al. 2016

Journal of Fish Diseases

View full text Add to dashboard Cite

Kynurenic acid (KYNA) is an endogenous substance produced on the kynurenine pathway which is primarily known for its neuroactive properties. Recently, it has been proven that KYNA is a selective ligand for G protein-coupled receptor (GPR 35), presented on immunocompetent cells such as T lymphocytes. This opens up new possibilities of its application as an immunostimulating substance in aquaculture. Thus far, no histopathological investigations in fish have been completed to evaluate influence of KYNA supplementation in feed. This study has been undertaken to determine the effect of feed supplementation with KYNA (2.5, 25, 250 mg kg of feed) for 28 days on the liver, gills and kidney in healthy fish and experimentally infected with Yersinia ruckeri. In a control group were observed a fatty liver, which is natural for this fish species in the autumn and winter season. As the dose of the supplement was increased, the fat liver changed, it decreased or completely disappeared. Additionally, inflammatory changes occurred in all the analysed organs, and their intensification was dose dependent. In the fish experimentally infected, KYNA caused aggravation of the signs in the liver, kidneys and gills, and the effect was dose dependent. The results implicate that KYNA may be a stressor for fish.

show abstract

Purification and characterization of kynurenine-2-oxoglutarate aminotransferase from the liver, brain and small intestine of rats

Cited by 49 publications

References 23 publications

Kynurenic Acid Influences the Respiratory Parameters of Rat Heart Mitochondria

Kynurenic Acid Influences the Respiratory Parameters of Rat Heart Mitochondria

Identity of Kynurenine: Pyruvate Aminotransferase with Histidine:Pyruvate Aminotransferase

Effect of feed supplementation with kynurenic acid on the morphology of the liver, kidney and gills in rainbow trout (Oncorhynchus mykiss Walbaum, 1792), healthy and experimentally infected with Yersinia ruckeri

Contact Info

Product

Resources

About