Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A test is described for the evaluation of hormone sensitivity of endometrial cancer in vivo. The concentrations of progesterone and estradiol receptors, and the activities of ornithine-decarboxylase and 17 beta-hydroxysteroid oxido-reductase enzymes have been measured in the tumor, before and after administration of the anti-estrogen tamoxifen. The responses observed, in particular the increase of progesterone receptor, could allow a more rational approach to hormonal therapy of endometrial cancer.
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PMID:[Response to an antiestrogen as a criterion for hormonal sensitivity of endometrial cancer]. 11 15

Subcellular localization of enzymes of arginine metabolism in Saccharomyces cerevisiae was studied by partial fractionation and stepwise homogenization of spheroplast lysates. These enzymes could clearly be divided into two groups. The first group comprised the five enzymes of the acetylated compound cycle, i.e., acetylglutamate synthase, acetylglutamate kinase, acetylglutamyl-phosphate reductase, acetylornithine aminotransferase, and acetylornithine-glutamate acetyltransferase. These enzymes were exclusively particulate. Comparison with citrate synthase and cytochrome oxidase, and results from isopycnic gradient analysis, suggested that these enzymes were associated with the mitochondria. By contrast, enzymatic activities going from ornithine to arginine, i.e., arginine pathway-specific carbamoylphosphate synthetase, ornithine carbamoyltransferase, argininosuccinate synthetase, and argininosuccinate lyase, and the two first catabolic enzymes, arginase and ornithine aminotransferase, were in the "soluble" fraction of the cell.
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PMID:Arginine metabolism in Saccharomyces cerevisiae: subcellular localization of the enzymes. 20 32

Proline-requiring mutants of Saccharomyces cerevisiae were isolated. Each mutation is recessive and is inherited as expected for a single nuclear gene. Three complementation groups cold be defined which are believed to correspond to mutations in the three genes (pro1, pro2, and pro3) coding for the three enzymes of the pathway. Mutants defective in the pro1 and pro2 genes can be satisfied by arginine or ornithine as well as proline. This suggests that the blocks are in steps leading to glutamate semialdehyde, either in glutamyl kinase or glutamyl phosphate reductase. A pro3 mutant has been shown by enzyme assay to be deficient in delta 1-pyrroline-5-carboxylate reductase which converts pyrroline-5-carboxylate to proline. A unique feature of yeast proline auxotrophs is their failure to grown on the rich medium, yeast extract-peptone-glucose. This failure is not understood at present, although it accounts for the absence of proline auxotrophs in previous screening for amino acid auxotrophy.
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PMID:Isolation and preliminary characterization of Saccharomyces cerevisiae proline auxotrophs. 37 40

The enzymes used in the identification of Gram negative bacteria belonging to the families of Enterobacteriaceae, Vibrionaceae, Parvobacteriaceae, Pseudomonadaceae and to the genera Alteromonas, Xanthomonas, Alkaligenes, Flavobacterium are classified arbitrarily by the author into enzymes essential for the diagnosis of the family (oxidase, nitratase), enzymes useful in the diagnosis of the genus or the species (ONPG-hydrolase, urease, oxidative desaminase, lysine decarboxylase and ornithine, arginine dihydrolase, thiosulphate reductase, pectinase), and into enzymes sought to confirm the diagnosis (tetrathionate reductase, gelatinase, lipase, DNase, amylase, beta-xylosidase, lecithinase). The technics permitting their identification are described and their distribution in the species and genera studied is reported.
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PMID:[Research technics of enzymes used in the diagnosis of gram negative bacteria (author's transl)]. 74 48

The Schizosaccharomyces pombe arginine anabolic genes encoding ornithine carbamoyltransferase (arg3) and acetylglutamate kinase/acetylglutamyl-phosphate reductase (arg11) were cloned by functional complementation of S. pombe arg3 and arg11 mutant strains from S. pombe DNA genomic libraries. Restriction analysis and sequencing of the two clones showed that both genes are located on a common DNA fragment. The arg3 gene encodes a 327-amino-acid polypeptide presenting a strong identity to Saccharomyces cerevisiae and human ornithine carbamoyltransferases. The arg11 gene encodes a 884-amino-acid polypeptide. The acetylglutamate kinase and acetylglutamate-phosphate reductase domains have been defined by their identity with the S. cerevisiae ARG5,6 protein. The cloned arg11 gene from S. pombe does not complement an arg5,6 mutation in S. cerevisiae, nor does the ARG5,6 gene complement the S. pombe arg11- mutation. In contrast, both ornithine-carbamoyltransferase-encoding genes function in S. pombe. However, the S. pombe arg3 gene complements only weakly an arg3 S. cerevisiae strain, which is in agreement with the low level of expression of the S. pombe gene in S. cerevisiae. The subcellular localization of both ornithine carbamoyltransferases in the two yeasts indicates that, in contrast to the S. pombe enzyme, more than 95% of the S. cerevisiae enzyme remains in the S. pombe cytoplasm. The low expression of S. pombe ornithine carbamoyltransferases in S. cerevisiae did not allow its localization. The promoters of S. pombe arg3 and arg11 genes do not present striking similarities among themselves nor with the promoters of the equivalent genes of S. cerevisiae.
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PMID:Cloning and sequencing of arg3 and arg11 genes of Schizosaccharomyces pombe on a 10-kb DNA fragment. Heterologous expression and mitochondrial targeting of their translation products. 131 66

The properties of a series of methotrexate analogs containing 2,omega-diaminoalkanoic acids have been investigated. The compounds were potent inhibitors of dihydrofolate reductase but, unlike methotrexate, they were also inhibitors of mammalian folylpolyglutamate synthetases. The potency of synthetase and reductase inhibition increased with increasing length of the 2,omega-diaminoalkanoate moiety. The most cytotoxic compound and the most potent inhibitor of both dihydrofolate reductase (I50 = 2.5 to 4 nM) and folylpolyglutamate synthetase (Ki ca. 4 microM) contained 2,5-diaminopentanoic acid (ornithine). These compounds were 70- to 100-fold less cytotoxic than methotrexate to human leukemia cell lines; however, they retained their potency against sublines resistant to methotrexate via defective transport. Their dual loci of enzyme inhibition and their efficacy against methotrexate transport-defective cell lines indicate that these compounds may be an important new class of antifol.
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PMID:Folylpolyglutamate synthetase inhibition and cytotoxic effects of methotrexate analogs containing 2,omega-diaminoalkanoic acids. 242 84

Various enzyme activities related to ornithine metabolism were studied using bovine lenses, ie, ornithine ketoacid transaminase, delta-1-pyrroline-5-carboxylate reductase, and delta-1-pyrroline-5-carboxylate dehydrogenase. Ornithine ketoacid transaminase activity was found in the lens epithelium; delta-1-pyrroline-5-carboxylate reductase activity was high in both lens epithelium and cortex plus nucleus; delta-1-pyrroline-5-carboxylate dehydrogenase activity was negligible in either lens epithelium or cortex plus nucleus. These results suggest that in the bovine lens ornithine is converted to proline by the cooperative action of ornithine ketoacid transaminase and delta-1-pyrroline-5-carboxylate reductase.
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PMID:Enzymes in ornithine-proline metabolic pathway in bovine lens. 384 Nov 68

We present a study of the enzymatic activities involved in the pathway for arginine catabolism by Agrobacterium tumefaciens. Nitrogen from arginine is recovered through the arginase-urease pathway; the genes for these two activities are probably chromosomally born. Arginase was found to be inducible during growth in the presence of arginine or ornithine. Urease was constitutively expressed. Ornithine, resulting from the action of arginase on arginine, could be used as a nitrogen source via transamination to delta 1-pyrroline-5-carboxylate and reduction of the latter compound to proline by a reductase (both enzymatic activities are probably chromosomally encoded). Ornithine could also be used as a carbon source. Thus, we identified an ornithine cyclase activity that was responsible for direct conversion of ornithine to proline. This activity was found to be Ti plasmid encoded and inducible by growth in medium containing octopine or nopaline. The same activity was also chromosomally encoded in some Agrobacterium strains. In such strains, this activity was inducible during growth in arginine-containing medium.
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PMID:Arginine catabolism in Agrobacterium strains: role of the Ti plasmid. 395 72

Fresh extracts of cells of Clostridium botulinum reduced a limited amount of ornithine to delta-aminovaleric acid, but at high substrate concentrations a considerable amount of an amino compound accumulated which was neutral at pH 4.2. Aging of the extracts at -10 C or freezing and thawing resulted in the loss of the ability to produce delta-aminovaleric acid, but the ability to produce the neutral compound was retained. This compound was separated by column chromatography, and was found to be identical to dl-proline with respect to (i) R(F) upon paper chromatography, (ii) migration rates upon paper ionophoresis, (iii) spectrum of the product of the ninhydrin reaction, (iv) oxidation with d-amino acid oxidase, and (v) rate of reduction to delta-aminovaleric acid by cell extracts. The intermediate role of proline in the reduction of ornithine to delta-aminovaleric acid was indicated by (i) rate studies with and without an added electron donor and with and without inhibitors of proline reductase, (ii) the initial accumulation of radioactive proline to the exclusion of radioactive delta-aminovaleric acid from (14)C-l-ornithine in the presence of low levels of carrier proline, and (iii) the initial accumulation of proline at low levels prior to a significant accumulation of delta-aminovaleric acid in reaction mixtures in which the latter compound was the primary product after a longer incubation time. The conversion of ornithine to proline was the rate-limiting step in the presence of a good electron donor (alanine). The mechanism of the conversion of ornithine to proline has not been established. Preliminary data indicated that it may involve an oxidation to glutamic-gamma-semialdehyde and its equilibrium product, Delta(1)-pyrroline-5-carboxylic acid.
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PMID:Proline as an intermediate in the reductive deamination of ornithine to delta-aminovaleric acid. 430 Oct 45

Mitochondrial enzymes in rat livers or intestines were investigated in experimental models with ethanol- or other hepatotoxic agent-induced liver injuries and extrahepatic cholestasis. In clinical experiment, activities of mitochondrial GOT (mGOT) and ornithine carbasmyl transferase (OCT) were examined in alcoholisms and patients with other various liver diseases. Results obtained are as follows; 1) The activities of OCT and mGOT were increased particularly at onset of acute hepatitis, in chronic active hepatitis and intrahepatic cholestasis, showing that mitochondria were injured strikingly in these diseases. The activities in alcoholics were not so great, however mGOT/total-GOT ratio was increased in level than in other diseases. 2) Changes in mitochondrial enzymes of rat liver treated with ethanol were too varied to catch the actual tendency in this pathologic state. 3) Administration of galactosamine, carbon tetrachloride, or alpha-naphthyl isothiocyanate (ANIT) caused a significant fall in activities of succinate cytochrome C reductase and OCT, along with increase in serum activity of OCT, indicating severe mitochondrial injury with these drugs. Extrahepatic cholestasis following bile duct ligation showed the same changes of mitochondrial enzymes in liver tissue and serum. 4) These data indicate that observation of activities of serum OCT, mGOT, along with mGOT/total-GOT ratio are useful for estimation of mitochondrial damage in extra- and intra-hepatic cholestasis, and acute or chronic active hepatitis. The changes in alcoholic fatty liver was not so subtle as compared with other liver diseases. 5) It is surmized that smooth endoplasmic reticulum was increased in content and pentose phosphate shunt was inhibited by chronic ethanol treatment, estimating from increased activities of NADH-ferricyanide reductase and gamma-glutamyl transpeptidase, and decreased activity of glucose-6-phosphate dehydrogenase. 6) The changes in hepatic enzymes with ethanol treatment were paralleled with those of intestinal ones, indicating that metabolic changes in intestine contribute someway in the formation of alcoholic fatty liver. 7) Chronic ethanol treatment induced lowered active transport in intestinal mucosa, which indicates inhibition in absorption of various nutrients by ethanol.
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PMID:[Experimental and clinical studies on enzymes of mitochondria in various liver diseases; with special reference to alcoholic liver disease (author's transl)]. 625 Sep 59


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