Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.4.1.2 (glutamate dehydrogenase)
4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Synthesis of glutamine synthetase (GS) in anaerobic batch cultures of Escherichia coli was repressed when excess NH4+ was available, but derepressed during growth with a poor nitrogen source. In wild-type bacteria there was only a weak inverse correlation between the activities of GS and glutamate dehydrogenase (GDH) during growth in various media. No positive correlations were found between the activities of GS and nitrite reductase, or between GS and cytochrome c552: both of these proteins were synthesized normally by mutants that contained no active GS. Although activities of GS and GDH were low in two mutants that are unable to synthesize cytochrome c552 or reduce nitrite because of defects in the nirA gene, the nirA defect was separated from the GS and GDH defects by transduction with bacteriophage P1. Attempts to show that catabolite repression of proline oxidase synthesis could be relieved during NH4+ starvation also failed. It is, therefore, unlikely that nitrite reduction or proline oxidation by E. coli are under positive control by GS protein. The regulation of the synthesis of enzymes for the utilization of secondary nitrogen sources in E. coli, therefore, different from that in Klebsiella aerogenes, but is similar to that in Salmonella typhimurium.
...
PMID:Lack of a regulatory function for glutamine synthetase protein in the synthesis of glutamate dehydrogenase and nitrite reductase in Escherichia coli K12. 1 79

The content of cytochromes a,b and c, the activity of marker enzymes of the matrix and inner membrane of the mitochondria: glutamate dehydrogenase and cytochrome oxidase, as well as the rate of absorption of O2 by root segments in the presence of respiratory substrates, oxygen, inhibitors of respiration, and dinitrophenol, were determined. The intensification of cell respiration in the phase of elongation is determined not so much by new formation of cytochrome components of the respiratory cycle (during this period there is an accumulation only of cytochrome c) as by reorganization of the respiratory cycle (primarily its portion NADH - cytochrome b) and synthesis of enzymes of the matrix.
...
PMID:Formation of the enzymatic apparatus of respiration in growing cells. Communication II. Reorganization of the respiratory cycle of mitochondria in the corn root tip. 16 96

One hour after a single i.v. dose of 250 mg/kg folic acid, the straight portion of distal tubules in the outer medulla of rat kidneys showed a distinct reduction in succinate dehydrogenase, NADH2-diaphorase, glutamate dehydrogenase, cytochrome oxydase, Na+/K+-ATPase, and acid phosphatase activity. In contrast, the proximal tubules exhibited only a reduction in glutamate dehydrogenase and alkaline phosphatase activity. At this time the straight portion of the distal tubules, whose enzyme activity had changed, showed partly regressive epithelial changes. 24 hours after folic acid administration an even greater reduction in enzyme activity had occurred in the straight portion of distal tubules; these structures also became dilated. The adjacent collecting tubules and the corresponding proximal tubules were also severely dilated, the proximal tubules showing a loss in enzyme acitivities similar to those observed in the distal tubules. 48 hours after folic acid administration the changes largely resembled those observed after 24 hours, but were more pronounced. At this time a tubular regeneration was observed. 72 hours after folic administration extensive normalization of the histological and histochemical changes had occured. It is postulated that a disturbance of the hairpin counter-current mechanism occurs as a result of a direct, concentration-dependent effect of folic acid on the enzymes of the energy supplying metabolism. A dilation in the region of the loop of Henle and the collecting tubules occurs subsequently.
...
PMID:Enzyme histochemistry of rat folic acid nephropathy. 19 86

Using the semi-continuous cultivation technique we could establish that specifically in Streptomyces noursei JA 3890b during growth on a medium supplied with D,L-alanine, NH4+, and maize starch there are two different phenotypes of the organism and stationary states of metabolism, respectively. The expression of either the metabolic state I with an enhanced capacity to oxidative deamination of alanine via the NAD+-dependent alanaine dehydrogenase or the metabolic state 2 which may be characterized by the preferred use of ammonium ions via the NADP+-dependent glutamate dehydrogenase was shown to depend strongly on the conditions of inoculum cultivation. When the amino acid permeases were derepressed by cultivating the inoculum cells on amino acid media, probably due to the defective mechanism of negative feedback control of amino acid influx in this strain an abnormously high uptake of alanine was observed that, consequently, was correlated to the enhanced oxidation of this amino acid as well as to the intensive production of ammonia within the cell. This overproduction of cellular NH4+ seems to bring about the subsequent repression of biosynthetic glutamate dehydrogenase and so on the accumulation of ammonia autocatalytically may rise up (metabolic state I). On the other hand, if the influx of alanine was kept low and the NADH oxidation was less efficient, respectively, or when there was high cellular activity of glutamate dehydrogenase the level of ammonia never did exceed the respressory limit and, accordingly, the expression of the metabolic state 2 was observed. Switching-over of metabolic flux from the state 2 towards the state 1 can be brought about either by increasing the level of nitrogen sources in the medium or by adding buffers pH greater than 7.5. In contrast, decrease of cellular level of NH4+ was shown to induce the transition of metabolic state 1 into the state 2. This can be achieved not only by limitation of nitrogen source but also by adding different aminobenzoic acids and, alternatively, effectors of membrane function (short-chain alcohols), inhibitors of cytochrome oxidases (sodium azide, potassium cyanide), heavy metal (Fe++)-chelating agents (catechol, 2,5'-dipyridyl, o-phenanthroline), beta-alanine, and buffers pH less than 7. This suggests that these effectors are capable of preventing the abnormously high influx of amino acids as well as its wasteful catabolism within the cell of S. noursei JA 3890b. Therefore, it seems likely that by this way the aminobenzoic acids and similar effectors can diminish the catabolite repression or inhibition of secondary metabolism by cellular excess of some nitrogen compounds in good agreement with its well-known stimulatory action on the biosynthesis of the antibiotic nourseothricin in this strain.
...
PMID:Regulative influence of o-aminobenzoic acid on the biosynthesis of nourseothricin in cultures of Streptomyces noursei JA 3890b. IV. Bistability of metabolism and the mechanism of action of aminobenzoic acids. 23 65

Seventeen strains of the new species Bacillus azotoformans were isolated by enrichment culture in peptone broth inoculated with pasteurized soil and then incubated under N2O at 32 degrees C. The bacterium is a Gram-negative rod, motile with peritrichous flagella, which produces oval spores without exosporia in swollen sporangia. However, the cells have thick walls, mesosomes, and persistent septa characteristic of Gram-positive bacteria. The bacterium lacks fermentative activity, does not attack carbohydrates, has complex growth requirements, and will grow anaerobically only if one of the following electron acceptors is present: NO3-, NO2-, N2O, S4O6--, or fumarate. Nitrate, nitrite, and nitrous oxide are denitrified with the production of N2. The microorganism is mesophilic, gives a positive oxidase reaction, synthesizes a type c cytochrome, and does not hydrolyse gelatin, starch, or "Tween 80." Poly-beta-hydroxybutyric acid is snythesized when the bacterium is grown in a medium containing DL-3-hydroxybutyrate. The following enzymes are present: nitrate reductase A, respiratory nitrite reductase, tetrathionate and fumarate reductases, and L-glutamate dehydrogenase. The following enzymes are absent: thiosulfate reductase, urease, lecithinase, arginine dihydrolase, phenylalanine deaminase, and catalase. For the 17 strains, the mean value of the G = C percent of the DNA is 39.8 +/- 1.2. All the strains are highly similar.
...
PMID:[Morphological, physiological and taxonomic studies of Bacillus azotoformans]. 65 12

The described bacterium was isolated by enrichment culture in peptone broth inoculated with garden soil, pasteurized and then put to incubate under N2O at 32 degrees. It is a Gram-negative rod, motile with peritrichous flagella, and producing oval spores without exosporium in swollen sporangia. However, cells have the thick walls, mesosomes and persistant septa characteristic of Gram-positive bacteria. It lacks fermentative activity, does not attack carbohydrates, has complex growth requirements, and will grow anaerobically only if one of the following electron acceptors is present: NO3, NO2, N2O, S4O6, and fumarate. Nitrate, nitrite, and nitrous oxide are denitrified with production of N2. The microorganism is mesophilic, gives a positive oxidase reaction, synthesizes a type of c cytochrome, and does not hydrolyse gelatin, starch nor "Tween 80". The following enzymes are present: nitrate reductase A, respiratory nitrite reductase, tetrathionate and fumarate reductases, L-glutamate dehydrogenase, and superoxide dismutase. The following enzymes are absent: thiosulfate reductase, urease, lecithinase, arginine dihydrolase, L-alanine dehydrogenase, phenylalanine desaminase, and catalase. The GC% of its DNA is 39. The bacterium described can be considered to be a new species. We propose the name Bacillus azotoformans n. sp.
...
PMID:[A new, sporulating, denitrifying, mesophilic bacterium: Bacillus azotoformans N. SP. (author's transl)]. 102 Aug 72

Mitochondria used in the present study were isolated from skeletal muscle of normal and thyroidectomized rats. The preparations were controlled by electron microscopy. It was not possible to find any morphological change induced by thyroidectomy, nevertheless, some difference appeared in the cytochrome contents which were slightly decreased. Oxygen consumption rates of thyroidectomized rat mitochondria were decreased when the particles were maintained in states 3 and 4 in the presence of various substrates, but the P/O ratios were not modified. The activities of mitochondrial enzymes were in general slightly affected by thyroidectomy except for glycerol-1-phosphate cytochrome c reductase and NADH rotenone sensitive cytochrome c reductase which were decreased and for glutamate dehydrogenase activity which was increased. The tRNA nucleotidyltransferase activity found in the mitochondrial matrix was not influenced by the absence of thyroid secretion. Normal rat muscle mitochondria incorporate 14C-leucine with an artificial ATP-generating system or with a respiratory substrate. The amino acid incorporation was decreased by thyroidectomy. Muscle mitochondria analyzed by polyacrylamide gel electrophoresis contained more than 30 protein components with MW ranging from 10.000 to 135.000. Thyroidectomy lowered the amount of a fraction of about 54.000 MW. It is not impossible that all the data observed in the absence of thyroid secretion are in relation with changes induced in the mitochondrial genome as previously shown in mitochondria isolated from liver or thyroidectomized rats.
...
PMID:[Effects of thyroidectomy of the rat on the structure and functions of skeletal muscle mitochondria]. 120 23

Cytochrome of the f type was isolated from the thermophilous autotrophic strain Chlorella pyrenoidosa Pringsheim 82T and purified on Sephadex G-75. The isolation procedure allowed a simultaneous production of glutamate dehydrogenase isoenzymes. From 100 g of Chlorella wet paste 100 to 120 nM of electrophoretically unicomponent protein with a molecular weight of 12,000 to 13,000 were isolated. The Chlorella cytochrome had an absorption spectrum in the visible light that was typical of the f type cytochromes.
...
PMID:[Cytochrome f from Chlorella pyrenoidosa Pringsheim 82 T]. 120 96

Squalene synthetase activity in liver microsomes from rats sacrificed at three different times of the diurnal cycle showed no significant differences. Addition of 4% cholestyramine to the food resulted in a marked increase in activity (280% of control), independent of the time of killing. 3-Hydroxy-3-methylglutaryl coenzyme A reductase and cholesterol 7 alpha-hydroxylase activity, determined as positive controls, were also found to be elevated by cholestyramine and additionally showed a diurnal variation. On the other hand, five control enzyme activities, not directly related to cholesterol metabolism, i.e. glutamate dehydrogenase, NADPH cytochrome-c reductase, beta-hexosaminidase, catalase and acyl coenzyme A oxidase, showed neither an influence of cholestyramine feeding nor a time of sacrifice dependent variation.
...
PMID:Regulation of squalene synthetase activity in rat liver: elevation by cholestyramine, but no diurnal variation. 294 75

The effects of different cerebro-protective agents on selected key enzymes of the energy metabolism of rat primary glial cultures and rat cerebral cortex were studied. As indicators for the capacity of the most important pathways of energy metabolism the following enzyme activities were determined: hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-P-DH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), and cytochrome-c-reductase (CCR). After a one week growth period, rat glial cultures were incubated for 3 or 4 weeks with the substances to be tested. Bencyclane (5 X 10(-5) mol/l) increased the activities of HK, G-6-P-DH, and LDH, whereas PFK and CCR were reduced. Pyritinol (10(-4) mol/l) led to a higher G-6-P-DH activity, simultaneously lowering the values for PFK, CCR, PK, LDH, and MDH. Under the influence of an extract of the leaves of Ginkgo bilobae (EGB; 100 mg/l) PFK, LDH, and MDH activities were reduced. All these alterations in enzyme activities went along with simultaneous reductions in protein content, therefore not allowing to exclude toxic effects with regard to the doses used. Moreover, direct interference with the analytical procedure was demonstrable for bencyclane and EGB. Piracetam (10(-3) mol/l), flunarizine (10(-6) mol/l), dihydroergocristine (5 X 10(-6) mol/l), and nicergoline (5 X 10(-6) mol/l) failed to induce any alteration in the employed doses. The most striking effects were obtained with meclofenoxate which was tested at 10(-3) and 10(-4) mol/l. The higher dose caused an elevation of HK, PFK, CCR, G-6-P-DH, GDH and MDH activities, while slightly reducing PK. With the lower dose of meclofenoxate CCR and G-6-P-DH activities were increased. Short-term incubation of the cultures with 10(-3) mol/l meclofenoxate for 24 hr led to an increase in LDH, G-6-P-DH, and GDH activities. Chronic incubation with meclofenoxate (10(-3) mol/l) followed by 48 hr deprivation of the drug resulted in elevated HK, PFK, CCR, G-6-P-DH, GDH, and MDH activities. These changes were accompanied by alterations in related metabolite levels. These include elevations in the concentration of creatine phosphate and fructose-1,6-bisphosphate, whereas glucose-6-phosphate levels were reduced. After one week of meclofenoxate deprivation the activities of CCR and G-6-P-DH were still elevated. The metabolites of meclofenoxate dimethylaminoethanol (DMAE; 10(-3) mol/l) and p-chlorophenoxyacetic acid (10(-3) mol/l) were also investigated.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Effects of cerebro-protective agents on enzyme activities of rat primary glial cultures and rat cerebral cortex. 294 86


1 2 3 Next >>

---