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:1.4.3.11 (glutamate dehydrogenase)
4,437 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twelve enzymes from mature pollen grains of maize were separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The separation in the second dimension was both in the presence and absence of sodium dodecyl sulfate (SDS). Ten of the investigated enzymes lost activity after separation in the presence of SDS, but those of esterases and acid phosphatase could be recovered. On the other hand, 2-D electrophoresis without SDS is suitable for the analysis of maize pollen pectinesterase, malate dehydrogenase, glutamic-oxalacetic transaminase, diaphorase, superoxide dismutase, and phosphoglucose isomerase. 1-D PAGE and isoelectric focusing (IEF) are sufficient to analyze glucose-6-phosphate dehydrogenase, alcohol dehydrogenase, shikimic dehydrogenase, and glutamate dehydrogenase. The possibility of applying 2-D electrophoresis for the analysis of enzymes from single stigma and stigma exudate is dicussed.
...
PMID:Maize pollen enzymes after two-dimensional polyacrylamide gel electrophoresis in the presence or absence of sodium dodecyl sulfate. 1182 13

Reference values for 18 plasma chemical variables in blue neck ostriches (Struthio camelus australis, n = 60, age 24-36 mo) were established for use in veterinary clinical practice using nonparametric statistics. The following values were established for the percentiles P2.5 and P97.5: sodium 147-157 mmol/L, calcium 2.4-4.8 mmol/L, inorganic phosphate 1.3-2.3 mmol/L, chloride 94-105 mmol/L, glucose 10.3-13.7 mmol/L, urea 0.5-0.8 mmol/L, uric acid 351-649 mumol/L, bile acids 8-33 mumol/L, total protein 39-56 g/L, albumin-globulin ratio 0.45-0.59, osmolality 304-330 mOsm/kg, alkaline phosphate 69-217 IU/L, aspartate aminotransferase 243-418 IU/L, gamma-glutamyltransferase 0-1 IU/L, creatine kinase 1648-4894 IU/L, glutamate dehydrogenase 8-17 IU/L, and lactate dehydrogenase 860-2236 IU/L. The plasma calcium concentration was significantly (P < 0.001; r = 0.74) related to the total protein concentration and an adjustment-formula for calcium was derived: adjusted Ca (mmol/L) = Ca (mmol/L)--0.09 TP (g/L) + 4.4. The influence of blood sample treatment on the plasma potassium concentration as seen in other avian species was demonstrated in a separate experiment, emphasizing the need to separate plasma and cells immediately after collection in avian blood samples.
...
PMID:Plasma chemistry reference values in ostriches. 1183 6

Proteins in extracts from cotyledons, hypocotyls, and roots of 5-d-old, dark-grown soybean (Glycine max L. Merr. cv Williams) seedlings were separated by polyacrylamide gel electrophoresis. Three isoforms of glutamate dehydrogenase (GDH) were resolved and visualized in gels stained for GDH activity. Two isoforms with high electrophoretic mobility, GDH1 and GDH2, were in protein extracts from cotyledons and a third isoform with the lowest electrophoretic mobility, GDH3, was identified in protein extracts from root and hypocotyls. Subcellular fractionation of dark-grown soybean tissues demonstrated that GDH3 was associated with intact mitochondria. GDH3 was purified to homogeneity, as determined by native and sodium dodecyl sulfate-polyacrylamide gels. The isoenzyme was composed of a single 42-kD subunit. The pH optima for the reductive amination and the oxidative deamination reactions were 8.0 and 9.3, respectively. At any given pH, GDH activity was 12- to 50-fold higher in the direction of reductive amination than in the direction of the oxidative deamination reaction. GDH3 had a cofactor preference for NAD(H) over NADP(H). The apparent Michaelis constant values for [alpha]-ketoglutarate, ammonium, and NADH at pH 8.0 were 3.6, 35.5, and 0.07 mM, respectively. The apparent Michaelis constant values for glutamate and NAD were 15.8 and 0.10 mM at pH 9.3, respectively. To our knowledge, this is the first biochemical and physical characterization of a purified mitochondrial NAD(H)-dependent GDH isoenzyme from soybean.
...
PMID:Purification of Mitochondrial Glutamate Dehydrogenase from Dark-Grown Soybean Seedlings. 1222 51

Several model systems were employed to assess indirect effects that occur in the process of using radiation inactivation analysis to determine protein target sizes. In the absence of free radical scavengers, such as mannitol and benzoic acid, protein functional unit sizes can be drastically overestimated. In the case of glutamate dehydrogenase, inclusion of free radical scavengers reduced the apparent target size from that of a hexamer to that of a trimer based on enzyme activity determinations. For glucose-6-phosphate dehydrogenase, the apparent target size was reduced from a dimer to a monomer. The target sizes for both glutamate dehydrogenase and glucose-6-phosphate dehydrogenase in the presence of free radical scavengers corresponded to subunit sizes when determinations of protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or immunoblotting were done rather than enzyme activity. The free radical scavengers appear to compete with proteins for damage by secondary radiation products, since irradiation of these compounds can result in production of inhibitory species. Addition of benzoic acid/mannitol to samples undergoing irradiation was more effective in eliminating secondary damage than were 11 other potential free radical scavenging systems. Addition of a free radical scavenging system enables more accurate functional unit size determinations to be made using radiation inactivation analysis.
...
PMID:Target size analysis by radiation inactivation: the use of free radical scavengers. 1598 20

To be appropriately excreted in urine, NH4+, the major component of urinary acid excretion, must be synthesized by proximal tubular cells, secreted into the proximal tubular fluid, reabsorbed by the medullary thick ascending limb (MTAL) to be accumulated in the medullary interstitium, and finally secreted in medullary collecting ducts. Several targets have been identified to account at the gene expression level for the adaptation of renal NH4+ synthesis and transport in response to a chronic acid load. These targets are the key enzymes of ammoniagenesis (mitochondrial glutaminase and glutamate dehydrogenase) and gluconeogenesis (phosphoenolpyruvate carboxykinase) and the Na+/H+(NH4+) exchanger NHE3 in the proximal tubule, the apical Na+-K+(NH4+)-2Cl- cotransporter of the MTAL, the basolateral Na+-K+(NH4+)-2Cl- cotransporter, and likely the epithelial Rh B and C glycoproteins in the collecting ducts. An acid pH per se appears to be a major factor in the control of the expression of these genes during metabolic acidosis probably through activation of pH sensors. Glucocorticoids may also act in concert with an acid pH to coordinate the adaptation of various tubular cell types. The present review focuses on some new aspects of NH3/ NH4+ transport and of regulations of gene expression that have recently emerged.
...
PMID:Renal handling of NH3/NH4+: recent concepts. 1611 88

Fermentation acids inhibited the growth and ammonia production of the amino-acid-fermenting bacterium Clostridium sporogenes MD1, but only when the pH was acidic. Such inhibition was traditionally explained by the ability of fermentation acids to act as uncouplers and decrease protonmotive force (Deltap), but C. sporogenes MD1 grows even if the Deltap is very low. Cell suspensions incubated with additional sodium chloride produced ammonia as rapidly at pH 5.0 as at pH 7.0, but cells incubated with additional sodium lactate were sensitive to even small decreases in extracellular pH. Similar results were obtained if the sodium lactate was replaced by sodium acetate or propionate. When extracellular pH declined, DeltapH increased even if sodium lactate was present. The cells accumulated intracellular lactate anion when the pH was acidic, and intracellular glutamate declined. Because amino acid deamination is linked to a transamination reaction involving glutamate dehydrogenase, the decrease in ammonia production could be explained by the decrease in intracellular glutamate. This latter hypothesis was consistent with the observation that extracellular glutamate addition restored amino acid deamination even though glutamate alone did not allow for the generation of ammonia.
...
PMID:Fermentation acids inhibit amino acid deamination by Clostridium sporogenes MD1 via a mechanism involving a decline in intracellular glutamate rather than protonmotive force. 1694 57

The aim of the study was examining the effect of fluoride ions and caffeine administration on glucose and urea concentration in blood serum and the activity of protein metabolism enzymes and selected enzymes of the urea cycle in rat liver. The study was carried out using 18 male Sprague-Daowley rats (4.5 mo old). Rats were divided into three groups. Group I received distilled water ad libitum. Group II received 4.9 mg F-/kg body mass/d of sodium fluoride in the water, and group III received sodium fluoride (in the above-mentioned dose) and 3 mg/kg body mass/d of caffeine in the water. After 50 d, the rats were anesthetized with thiopental and fluoride ions, glucose, and urea concentration in blood serum were determined. Also determined were the activities of aspartate aminotransferase, alanine aminotransferase glutamate dehydrogenase, ornithine carbamoylotransferase and arginase in liver homogenates. Liver was taken for pathomorphological examinations. The applied doses of F- (4.9 mg/kg body mass/d) and F- + caffeine (4.9 mg F-/kg body mass/d + 3 mg caffeine/kg body mass/d) resulted in a statistically significant increase of fluoride ion concentration in blood serum, a slight increase of the glucose concentration, and no changes in the concentration of urea in blood serum. This might testify to the absence of kidney lesions for the applied concentrations of F-. No change in the functioning of hepatocytes was observed; however, slight disturbances have been noted in the functioning of the liver, connected with the activation of urea cycle, increase of arginase activity, and accumulation of F- in this organ. There was no observed significant influence of caffeine supplementation on the obtained results.
...
PMID:Influence of sodium fluoride and caffeine on the concentration of fluoride ions, glucose, and urea in blood serum and activity of protein metabolism enzymes in rat liver. 1702 82

Fuel stimulation of insulin secretion from pancreatic beta-cells is thought to be mediated by metabolic coupling factors that are generated by energized mitochondria, including protons, adenine nucleotides, and perhaps certain amino acids (AA), as for instance aspartate, glutamate, or glutamine (Q). The goal of the present study was to evaluate the role of such factors when insulin release (IR) is stimulated by glucose or AA, alone or combined, using (31)P, (23)Na and (1)H NMR technology, respirometry, and biochemical analysis to study the metabolic events that occur in continuously superfused mouse beta-HC9 cells contained in agarose beads and enhanced by the phosphodiesterase inhibitor IBMX. Exposing beta-HC9 cells to high glucose or 3.5 mM of a physiological mixture of 18 AA (AAM) plus 2 mM glutamine caused a marked stimulation of insulin secretion associated with increased oxygen consumption, cAMP release, and phosphorylation potential as evidenced by higher phosphocreatine and lower P(i) peak areas of (31)P NMR spectra. Diazoxide blocked stimulation of IR completely, suggesting involvement of ATP-dependent potassium (K(ATP)) channels in this process. However, levels of MgATP and MgADP concentrations, which regulate channel activity, changed only slowly and little, whereas the rate of insulin release increased fast and very markedly. The involvement of other candidate coupling factors was therefore considered. High glucose or AAM + Q increased pH(i). The availability of temporal pH profiles allowed the precise computation of the phosphate potential (ATP/P(i) x ADP) in fuel-stimulated IR. Intracellular Na+ levels were greatly elevated by AAM + Q. However, glutamine alone or together with 2-amino-2-norbornanecarboxylic acid (which activates glutamate dehydrogenase) decreased beta-cell Na levels. Stimulation of beta-cells by glucose in the presence of AAM + Q (0.5 mM) was associated with rising cellular concentrations of glutamate and glutamine and strikingly lower aspartate levels. Methionine sulfoximine, an inhibitor of glutamine synthetase, blocked the glucose enhancement of AMM + Q-induced IR and associated changes in glutamine and aspartate but did not prevent the accumulation of glutamate. The results of this study demonstrate again that an increased phosphate potential and a functional K(ATP) channel are essential for metabolic coupling during fuel-stimulated insulin release but illustrate that determining the identity and relative importance of all participating coupling factors and second messengers remains a challenge largely unmet.
...
PMID:Metabolic and ionic coupling factors in amino acid-stimulated insulin release in pancreatic beta-HC9 cells. 1726 32

NAD-dependent l-glutamate dehydrogenase (NAD-GDH) activity was detected in cell extract from the psychrophile Janthinobacterium lividum UTB1302, which was isolated from cold soil and purified to homogeneity. The native enzyme (1,065 kDa, determined by gel filtration) is a homohexamer composed of 170-kDa subunits (determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis). Consistent with these findings, gene cloning and sequencing enabled deduction of the amino acid sequence of the subunit, which proved to be comprised of 1,575 amino acids with a combined molecular mass of 169,360 Da. The enzyme from this psychrophile thus appears to belong to the GDH family characterized by very large subunits, like those expressed by Streptomyces clavuligerus and Pseudomonas aeruginosa (about 180 kDa). The entire amino acid sequence of the J. lividum enzyme showed about 40% identity with the sequences from S. clavuligerus and P. aeruginosa enzymes, but the central domains showed higher homology (about 65%). Within the central domain, the residues related to substrate and NAD binding were highly conserved, suggesting that this is the enzyme's catalytic domain. In the presence of NAD, but not in the presence of NADP, this GDH exclusively catalyzed the oxidative deamination of l-glutamate. The stereospecificity of the hydride transfer to NAD was pro-S, which is the same as that of the other known GDHs. Surprisingly, NAD-GDH activity was markedly enhanced by the addition of various amino acids, such as l-aspartate (1,735%) and l-arginine (936%), which strongly suggests that the N- and/or C-terminal domains play regulatory roles and are involved in the activation of the enzyme by these amino acids.
...
PMID:Gene cloning and characterization of the very large NAD-dependent l-glutamate dehydrogenase from the psychrophile Janthinobacterium lividum, isolated from cold soil. 1752 98

Carbon tetrachloride (CCl(4)) was used to induce liver fibrosis in the rat. Using this model, we have identified changes in serum and urinary clinical chemistry parameters, and characterized histopathological lesions in the liver. Two experiments were conducted. In Experiment 1, rats were dosed at six levels of CCl(4) (0.06-0.36 ml/kg) twice weekly for 6 weeks, followed by a 6-week non-dosing recovery period (week 12). Livers were removed for histology at 6 and 12 weeks and serum parameters analysed. In Experiment 2, rats were given seven dose levels of CCl(4) (0.4-1.0 ml/kg) twice weekly for 6 weeks, followed by a 6-week recovery period (week 12); urine samples were analysed at 3, 6, 9 and 12 weeks using one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Liver fibrosis was evident at 6 weeks in Experiments 1 and 2, and the activity of serum enzymes (including alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase) was increased. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis (Experiment 2) revealed a protein band at 18.4 kDa in urine from rats treated with CCl(4), not present in control urine, which was identified as copper/zinc superoxide dismutase (Cu/Zn SOD). Western blotting revealed that SOD was increased in urine from rats treated with CCl(4) at 3 and 6 weeks, but not at 9 and 12 weeks. We conclude that Cu/Zn SOD is a urinary marker of hepatic necrosis, but not hepatic fibrosis.
...
PMID:Comprehensive characterization of serum clinical chemistry parameters and the identification of urinary superoxide dismutase in a carbon tetrachloride-induced model of hepatic fibrosis in the female Hanover Wistar rat. 1787 38


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---