Disease relevance of Oplah

• When the reaction catalyzed by 5-oxoprolinase of Pseudomonas putida was carried out to 90% completion in H2(18)O, the residual 5-oxoproline was found to contain 18O in the amide carbonyl oxygen atom [1].

High impact information on Oplah

• 5-Oxoprolinase (EC 3.5.2) catalyzes a reaction in which the endergonic cleavage of 5-oxo-L-proline to form L-glutamate is coupled to the exergonic hydrolysis of ATP to ADP and inorganic phosphate [2].
• The amino acid sequence of rat kidney 5-oxo-L-prolinase determined by cDNA cloning [2].
• Here we report the cloning of rat kidney 5-oxoprolinase with preliminary expression studies. cDNA clones encoding the enzyme were isolated by screening a lambdagt11 cDNA library beginning with a degenerate oligonucleotide probe based on peptide sequence data obtained from the purified enzyme [2].
• Using 5-[18O]oxo[5-13C]proline (97 and 79.5 atom % excess, 13C and 18O, respectively), the disappearance of the 18O-labeled and unlabeled 5-oxoproline and formation of the corresponding glutamate species were followed in the reactions catalyzed by purified preparations of 5-oxoprolinase isolated from Pseudomonas putida and from rat kidney [3].
• 5-Oxoprolinase catalyzes the ATP-dependent decyclization of 5-oxo-L-proline to L-glutamate [3].

Anatomical context of Oplah

• The activities of gamma-glutamyl transpeptidase, 5-oxoprolinase, and gamma-glutamyl cysteine synthetase, and levels of glutathione were measured in testis homogenates and Sertoli cell preparations obtained from 10-, 18-, and 26-day-old rats [4].
• The reduced glutathione levels and the enzymes gamma-glutamyl-transpeptidase, 5-oxoprolinase and gamma-glutamylcysteine synthetase, which participate in the metabolism of glutathione through the gamma-glutamyl cycle, were determined in explants from the lactating mammary gland of the rat [5].

Associations of Oplah with chemical compounds

• In the presence of very high glutamate concentrations, a slow reversal of the 5-oxoprolinase reaction was demonstrated by measuring ATP formation [6].
• Intermediates in the 5-oxoprolinase reaction were not detected by exchange experiments with radioactive ADP and phosphate, nor were they trapped by adding hydroxylamine [6].
• These results demonstrate that astroglial cells prefer cystine from cysteine for glutathione synthesis and express uptake systems for N-acetylcysteine, 2-oxothiazolidine-4-carboxylic acid, and cystathionine, as well as the enzymes N-deacetylase, 5-oxoprolinase, and cystathionine gamma-lyase [7].
• In contrast, generation of cysteine from 2-oxothiazolidine-4-carboxylate by the reaction of 5-oxoprolinase or from methionine by the transsulfuration pathway appears not to take place in these cultured neurons [8].
• The enzymes, gamma-glutamylamine cyclotransferase and 5-oxoprolinase, known to occur in animal kidney are at least in part responsible for the observed high availability of isopeptide bound lysine [9].

Analytical, diagnostic and therapeutic context of Oplah

• The molecular weight of 5-oxoprolinase from rat kidney was estimated by gel filtration on Sephadex G-200 and G-150 to be 460 000 +/- 30 000 [10].
• The enzyme 5-oxoprolinase was purified from rat kidney 285-fold to apparent homogeneity, as judged by analytical disc electrophoresis and discontinous polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate [11].

References