Aspects of energetic and intermediary metabolism were studied in a colon adenocarcinoma cell line (HT29) by multinuclear magnetic resonance spectroscopy. Experiments were carried out on the HT29-D4 clone, which was isolated by limit dilution techniques. This clone, usually undifferentiated (D4-UD), can be maintained in a differentiated state (D4-D) in a glucose-free medium. Metabolic data were ...

To clarify the biochemical mechanism of chloramphenicol induced erythroid suppression, effect on ALA (delta-aminolevulinic acid) synthetase activity in erythroid cells was studied. Chloramphenicol mice had no effect on ALA synthetase activity. However, AL...

Enzyme assays using the gamma-glutamyl transferase method provided estimates of glutamine synthetase activity in brain and liver tissues of Rana catesbeiana and Rana cancrivora. Glutamine synthetase specific activity in liver and brain tissues were not si...

The chromatographic properties of glutamine synthetase isoforms have been investigated in a wide range of higher plant leaves and shoots using ion exchange chromatography. Different patterns of glutamine synthetase isoform content were observed. Among higher plants, four patterns or groups could be recognized. The first group is characterized by having ...

specific activity of glutamine synthetase following such treatment. ... Glutamine synthetase (GS) is a rather ubiquitous enzyme found in both ...

... infection liver glycogen disappears rapidly; liver lipid increases; liver glycogen synthetase, active form, is inhibited, while UTP synthetase, and ...

Jun 16, 2011 ... Title: Changes in polyamines, inorganic ions and glutamine synthetase activity in response to nitrogen availability and form in red spruce ...

The regulation of glutamine synthetase by glucocorticoids in rat skeletal muscles was studied. Administration of dexamethasone strikingly enhanced glutamine synthetase activity in plantaris and soleus muscles. The dexamethasone-mediated induction of gluta...

The particulate aminoacyl-tRNA synthetases of rat liver were copurified about 1000-fold with more than 20% yields for individual synthetase activities. Measurements of aminoacylation activities showed that lysyl-, arginyl-, leucyl-, isoleucyl-, and methionyl-tRNA synthetases in the purified ...

The regulation of fatty-acid synthetase has been studied in liver, adipose tissue, and brain of diabetic and normal rats in relation to insulin administration and glucose or fructose feeding. The data indicate that: (1) insulin is not necessary for regulation of synthetase activity in liver but may be necessary in adipose tissue; (2) ...

Exposure to N2O inactivates cob[I]alamin and interferes with the activity of methionine synthetase, of which cob[I]alamin is a coenzyme. Less directly, it stops the formation of folate polyglutamate from tetrahydrofolates. Studies on the activity of folate polyglutamate synthetase in rat liver in vivo were carried ...

The metabolism of glutamine in the leaf and subtended fruit of the aging pea (Pisum sativum L. cv. Burpeeana) has been studied in relation to changes in the protein, chlorophyll, and free amino acid content of each organ during ontogenesis. Glutamine synthetase [EC 6.3.1.2] activity was measured during development and senescence in each organ. Glutamate ...

Density gradient separation of plastids from leaf and root tissue was carried out. The distribution in the gradients of the activity of the following enzymes was determined: nitrite reductase, glutamine synthetase, acetolactate synthetase, aspartate aminotransferase, catalase, cytochrome oxidase, and triosephosphate isomerase. The ...

Fast-growing revertants have been selected from a slow-growing lysyl-tRNA synthetase mutant. All of the revertants had increased lysyl-tRNA synthetase activity compared with the mutant (5- to 85-fold), and in some revertants this amounted to two to three times the wild-type synthetase activity. ...

Enzyme assays using the gamma-glutamyl transferase method provided estimates of glutamine synthetase activity in rat brain homogenates subjected to a pure oxygen environment for over three hours. No loss of activity was detected versus controls subjected ...

Enzyme assays using the gamma-glutamyl transferase method provided estimates of glutamine synthetase activity in tissues from 18 species of fish. These species included Chinook salmon, Pacific herring, carp, channel catfish, Pacific hagfish, ratfish, spin...

The production of toxic ergopeptine alkaloids by the fungi Claviceps purpurea and Neotyphodium coenophialum involves the activity of one or more nonribosomal peptide synthetases. Claviceps purpurea and N. coenophialum each have several different peptide synthetase genes, fragments of which have been cloned previously. An additional ...

The biosynthesis of aminocoumarin antibiotics involves the action of amide synthetases which construct amide bonds between aminocoumarins and various acyl moieties. Libraries of aminocoumarin analogues have been generated by in vivo fermentation, via feeding known amide synthetase substrates into producing microbial strains. Critically, such feeding ...

1. Only two aminoacyl-tRNA synthetases from Chinese hamster ovary cells are found associated with ribosomes and polyribosomes. 2. Phenylalanyl-tRNA synthetase activity is found with the 60S subunit, 80S monoribosome and individual polyribosomes. An additional 15S form of the enzyme is also seen. 3. Lysyl-tRNA ...

The activity of phosphorylase as well as that of uridine diphosphate glucose glycogen synthetase decreased beginning with the very earliest periods of ...

... Descriptors : *Anemias, *Erythrocytes, Enzyme inhibitors, Nitrogen compounds, Enzymes, Biochemistry, Laboratory animals, Mice, Experimental ...

The effects of in vivo administration of 6 compounds on the activity of delta-aminolevulinic acid (ALA) synthetase and heme oxygenase were determined. The order of decreasing potency in reducing ALA synthetase activity was heme, bilirubin, protoporphyrin ...

The effects of in vivo administration of 6 compounds on the activity of delta-aminolevulinic acid (ALA) synthetase and heme oxygenase were determined. The order of decreasing potency in reducing ALA synthetase activity was heme, bilirubin, protoporphyrin IX, bilirubin dimethyl es...

The distribution of 10-formyltetrahydrofolate synthetase, which activates formate for use as a one-carbon donor in a variety of biosynthetic reactions, was determined for a variety of eubacteria. Organisms from several genera were found to lack detectable synthetase activity; however, all organisms tested were ...

Intermittent acute porphyria has recently been distinguished biochemically from other genetic hepatic porphyrias by the observation of diminished hepatic uroporphyrinogen I synthetase activity and increased ?-aminolevulinic acid synthetase activity. Since deficient uroporphyrinogen I synthetase ...

... Acetyl-coa Carboxylase (ACCase) Inhibitor�Resistant Wild Oat (Avena fatua) Biotypes in the Pacific NorthwestAhmet Uludag, Kee Woong ... diclofop, fenoxaprop, pinoxaden, quizalofop, sethoxydim, tralkoxydim...

The fidelity of tRNA aminoacylation is dependent in part on amino acid editing mechanisms. A hydrolytic activity that clears mischarged tRNAs typically resides in an active site on the tRNA synthetase that is distinct from its synthetic aminoacylation active site. A second pre-transfer editing pathway that ...

Bacillus subtilis carries two genes, thyA and thyB, each encoding different protein products, with thymidylate synthetase (TSase) activity. Either of these genes alone is sufficient for thymidine independence in B. subtilis. In addition there exist two B....

Mar 1, 2011 ... Similarly, an acetyl-CoA synthetase associated predominantly with anaerobic ... were three mitochondrial enzymes that attained maximal activity only under ... Abstract: Acetyl-coenzyme A synthetase in aerobic yeast cells ...

A plant cell which is resistant to a herbicidal glutamine synthetase inhibitor, wherein the resistance is caused by levels of GS activity which, when present in an otherwise herbicidal GS inhibitor sensitive plant cell, render the cell substantially resistant to the herbicidal GS-inhibitor.

.A. Steitz, Insights into editing from an ile-tRNA synthetase structure with tRNAile and mupirocin, Science

Exposure of rats to environmental-stress conditions of hypobaria, hypoxia and cold did not alter the activity of hepatic delta-aminolaevulinate synthetase. Induction of the enzyme by diethoxycarbonyldihydrocollidine was inhibited when the rats were expose...

Disodium ethylenediamine tetraacetic acid and/or allylisopropylacetamide administration to rat pups did not evoke a premature induction of hepatic d-aminolevulinic acid synthetase. Administration of iron to adult rats did not alter d-aminolevulinic acid synthetase activity and ha...

Access to the article is free, however registration and sign-in are required. Protein synthesis depends on the ability of the 20 aminoacyl tRNA synthetases to add the correct amino acid to the transfer RNA (tRNA) containing the corresponding anticodon. Although in most organisms it transpires that there is one synthetase for each amino acid, some archaea ...

Glutamine synthetase (GS) is ubiquitously expressed in human tissues, being involved in ammonia detoxification and interorgan nitrogen flux. Inherited systemic deficiency of glutamine based on a defect of glutamine synthetase was recently described in two newborns with an early fatal course of disease. Glutamine was largely absent in their serum, urine and ...

After separation of a mitochondria-free extract of rabbit reticulocytes into a fraction of a ribosome-free extract and a fraction of mono- and polyribosomes the major portion of the aminoacyl-tRNA synthetase activity was found in the fraction of mono- and polyribosomes. All 15 of the aminoacyl-tRNA synthetases were found, although in ...

Human asparagine synthetase was expressed in Escherichia coli. Synthesis of the enzyme was demonstrated by immunoblotting and by complementation of asparagine auxotrophy in E. coli. The recombinant enzyme was shown to have both the ammonia- and glutamine-dependent asparagine synthetase activity in vitro. Compared to asparagine ...

Disease-causing mutations occur in genes for aminoacyl tRNA synthetases. That some mutations are dominant suggests a gain of function. Native tRNA synthetases, such as tyrosyl-tRNA synthetase (TyrRS) and tryptophanyl-tRNA synthetase, catalyze aminoacylation and are also procytokines that are ...

The URA7-encoded CTP synthetase [EC 6.3.4.2, UTP:ammonia ligase (ADP-forming)] in the yeast Saccharomyces cerevisiae is phosphorylated on a serine residue and stimulated by cAMP-dependent protein kinase (protein kinase A) in vitro. In vivo, the phosphorylation of CTP synthetase is mediated by the RAS/cAMP pathway. In this work, we examined the hypothesis ...

Histidinol-resistant (HisOHR) mutants with up to a 30-fold increase in histidyl-tRNA synthetase activity have been isolated by stepwise adaptation of wild-type Chinese hamster ovary (CHO) cells to increasing amounts of histidinol in the medium. Immunoprecipitation of [35S]methionine-labeled cell lysates with antibodies to histidyl-tRNA ...

The phosphorylation of the highly purified aminoacyl-tRNA synthetase complex from rabbit reticulocytes was examined. The synthetase complex contained, in addition to eight aminoacyl-tRNA synthetases, three unidentified proteins and was free of endogenous protein kinase activity. Incubation of the complex with ...

3-Deoxy-d-arabinoheptulosonate 7-phosphate (DAHP) synthetase and anthranilate synthetase are key regulatory enzymes in the aromatic amino acid biosynthetic pathway. The DAHP synthetase activity of Hansenula polymorpha was subject to additive feedback inhibition by phenylalanine and tyrosine but not by tryptophan. ...

A group of rats was given a vitamin A deficient diet, while a control group was given a normal diet. The experimental rats were exposed to 600R of ionizing radiation and were killed 3 hrs later. Determinations were made on the activity of retinol hydrolase and retinyl palmitate synthetase in intestinal mucosa and isolated membranes. Hydrolase (RPH) ...

Carbamoyl phosphate synthetase activity was measured in partially purified extracts from cotyledons of developing and germinating seeds of Pisum sativum L. Some properties of the enzyme were established. During cotyledon development, the activity initially increased sharply but decreased during further development. The ...

The attachment of each of the 20 naturally occurring amino acids to their cognate tRNA isoaccepting families is catalyzed by a specific aminoacyl-tRNA synthetase. The structural genes encoding 10 of these enzymes have been assigned to specific human chromosomes. The HARS, LARS, RARS, and TARS genes, encoding histidyl-, leucyl-, arginyl-, and threonyl-tRNA ...

An expression vector was constructed that carries part of the human BK papovavirus with 0.5 kilobases of (2'-5')oligoadenylate (2-5A) synthetase cDNA inserted in inverted orientation downstream from the virion proteins (VP) promoter and the neomycin-resistance gene neo under the control of a simian virus 40 promoter. Cells transfected with this vector and ...

A cytidine 5'-monophospho-N-acetylneuraminic acid (CMP-Neu5Ac) synthetase was found in a crude extract prepared from Photobacterium leiognathi JT-SHIZ-145, a marine bacterium that also produces a ?-galactoside ?2,6-sialyltransferase. The CMP-Neu5Ac synthetase was purified from the crude extract of the cells by a combination of anion-exchange and gel ...

The stability of rat hepatic trihydroxycoprostanoyl-CoA syntethase was studied in its native membrane environment and after solubilisation by Triton X-100, and compared to that of choloyl-CoA synthetase. The lability of both delipidated enzymes could be suppressed by high concentrations of polyols such as sucrose and glucose. Addition of phospholipids to the assay mixtures was ...

Derivatives of methionine sulfoximine (MSO) and phosphinothrycin (PPT), which are analogues of glutamate, exhibit selective herbicidal activity. This effect is accounted for by impairments of nitrogen metabolism, resulting from inhibition of its key enzyme in plants, glutamine synthetase (EC 6.3.1.2). Inhibition of the enzyme causes ammoniac nitrogen to ...

We have investigated the localization of palmitoyl-CoA (hexadecanoyl-CoA) synthetase (EC 6.2.1.3) and cerotoyl-CoA (hexacosanoyl-CoA) synthetase in peroxisomes isolated from rat liver. Palmitoyl-CoA and cerotoyl-CoA synthetases, like acyl-CoA: dihydroxyacetone phosphate acyltransferase (EC 2.3.1.42), are present in the peroxisomal ...

Inositol-requiring mutants of Saacharomyces cerevisiae were tested in cell extracts for the ability to convert glucose-6-phosphate to inositol-phosphate (IP synthetase) and inositol (IP phosphatase). Mutants representing any one of 10 unlinked loci conferring the inositol requirement were unable to synthesize either compound in an assay with glucose-6-phosphate as the ...

a study of the content of electrolytes, "glycogen" and also phosphorylase and glycogen-synthetase activity in the musculus gastrocnemium, musculus soleus ...

Jan 26, 2011 ... + Response of Crown Gall Tissue to the Space Environment: Glutamine Synthetase Activity (COS 782-4) � + Responses of Crown Gall Tissue to ...

... cyclase and suppression of squalene synthetase activities in plant cell cultures treated with fungal elicitor. Plant Physiol. 88:1291� ... ...

... carp, channel catfish, Pacific hagfish, ratfish, spiny dogfish, copper rockfish, Pacific cod, fresh-water and salt-water stingray, and Pacific lamprey. ...

CTP synthetase is an essential enzyme that generates the CTP required for the synthesis of nucleic acids and membrane phospholipids. In this study, we examined the phosphorylation of the human CTPS1-encoded CTP synthetase 1 by protein kinase A. CTP synthetase 1 was expressed and purified from a Saccharomyces cerevisiae ura7Delta ...

CTP synthetase is an essential enzyme that generates the CTP required for the synthesis of nucleic acids and membrane phospholipids. In this work, we examined the phosphorylation of the human CTPS1-encoded CTP synthetase 1 by protein kinase A. CTP synthetase 1 was expressed and purified from a Saccharomyces cerevisiae ura7? ura8? ...

The first two steps of urea synthesis in liver of marine elasmobranchs involve formation of glutamine from ammonia and of carbamoyl phosphate from glutamine, catalysed by glutamine synthetase and carbamoyl-phosphate synthetase, respectively [Anderson & Casey (1984) J. Biol. Chem. 259, 456-462]; both of these enzymes are localized exclusively in the ...

1. Aspergillus nidulans, Neurospora crassa and Escherichia coli were grown on media containing a range of concentrations of nitrate, or ammonia, or urea, or l-glutamate, or l-glutamine as the sole source of nitrogen and the glutamate dehydrogenate and glutamine synthetase of the cells measured. 2. Aspergillus, Neurospora and Escherichia coli cells, grown on l-glutamate or on ...

Glutamine synthetase from the photosynthetic bacterium Rhodospirillum rubrum is the target of both ATP- and NAD-dependent modification. Incubation of R. rubrum cell supernatant with ({alpha}-{sup 32}P)NAD results in the labeling of glutamine synthetase and two other unidentified proteins. Dinitrogenase reductase ADP-ribosyltransferase does not appear to be ...

Cell lines that have high levels of resistance to beta-aspartylhydroxamate and elevated levels of asparagine synthetase activity were selected in two steps from Chinese hamster ovary cells. Resistance to beta-aspartylhydroxmate was transferred into sensitive cells by using total genomic DNA derived from the dominant two-step mutants. The surviving colonies ...

It is detected that interferon-dependent 2',5'-oligoadenylate synthetase is a sensitive index of immunocompetent cells functional state under transformed environment conditions. Microgravitation and ionising radiation induce increase of investigated enzyme activity in rat lymphocytes, which can be a result of lymphoid cells compensatory mechanisms starting ...

Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along ...

Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along ...

Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along ...

A variety of particle-bound synthetases that use sugar nucleotides as glycosyl donors for the formation of polysaccharides similar to those of the cell wall have been demonstrated in mung beans and other plant tissues,¹ but the particles in question have not been previously identified.^{2, 3} The polysaccharide ...

The effect of lead nitrate on delta-aminolevulinic acid synthetase (ALA synthetase), the first and rate-limiting enzyme of the heme biosynthetic pathway, was studied by using an established rat liver cell line (RLC-GAI). Lead was shown to produce a time-dependent increase in ALA synthetase activity, with a maximum ...

The effect of lead nitrate on delta-aminolevulinic acid synthetase (ALA synthetase), the first and rate-limiting enzyme of the heme biosynthetic pathway, was studied by using an established rat liver cell line (RLC-GAI). Lead was shown to produce a time-dependent increase in ALA synthetase activity, with a maximum ...

Ultramicrochemical techniques were utilized to assay glycogen synthetase (EC 2.4.1.11) activity in cell samples of Dictyostelium discoideum as small as 0.01 mug (dry weight) in reaction volumes of 0.1 mul. The activity was assayed by an amplification procedure employing the enzymatic cycling of pyridine nucleotides. These techniques ...

Aminoacyl-tRNA synthetases are essential enzymes that help to ensure the fidelity of protein translation by accurately aminoacylating (or �charging�) specific tRNA substrates with cognate amino acids. Many synthetases have an additional catalytic activity to confer amino acid editing or proofreading. This ...