Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: CAS:6893-26-1 (glutamate)
 73,096 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dihydrofolate synthetase (EC 6.3.2.12) responsible for catalyzing the synthesis of dihydrofolic acid from dihydropteroic acid and L-glutamic acid was purified about 130-fold from extracts of Serratia indica IFO 3759 by ammonium sulfate fractionation, DEAE-Sephadex column chromatography, Sephadex G-200 gel filtration, and DEAE-cellulose column chromatography. The enzyme preparation obtained was shown to be homogeneous by DEAE-cellulose column chromatography and ultracentrifugal analysis. The sedimentation coefficient of this enzyme was 3.9 S, and the molecular weight was determined to be about 47,000 by Sephadex G-100. The optimum pH for the reaction was 9.0. The enzymatic reaction required dihydropteroate, L-glutamate and ATP as substrates, and Mg2+ and K+ as cofactors. gamma-L-Glutamyl-L-glutamic acid cannot replace L-glutamic acid as the substrate. Neither pteroic acid nor tetrahydropteroic acid can be used as the substrate. ATP was partially replaced by ITP or GTP. The enzyme reaction was inhibited by the addition of AD, but not by AMP. One mole of dihydrofolate, 1 mole of ADP and 1 mole of orthophosphate were produced from each 1 mole of dihydropteroic acid, L-glutamic acid, and ATP by the following equation: 7,8-Dihydropteroic acid ml-Glutamic acid matp Mg2+, K+ leads to Dihydrofolic acid + ADP + Pi. These results suggest that the systematic name for the dihydrofolate synthetase is 7,8-dihydropteroate: L-glutamate ligase (ADP).
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PMID:Purification and properties of the dihydrofolate synthetase from Serratia indica. 0 96

When phosphate and tyroxine (activators of brain glutaminase) are used in small amounts, a potentiation of their stimulatory effect is observed. Higher concentrations exhibit an opposite effect. Glutamic acid has a strong inhibitory effect on all the activators of glutaminase given separately. The inhibitory effect of glutamate increases on lowering the pH. On the other hand the potentiation observed on adding two stimulators is increased greatly in the presence of glutamate. On the addition of tyroxine to other stimulators a greater potentiation and rise of glutaminase activity are observed. The potentiation, which occurs on the joint addition of phosphate and tyroxine, is raised with the increase of the amount of glutamic acid, while on the contrary on joining phosphate with other stimulators potentiation is reduced. Potentiation is variable and depends on the pH. Preincubation of brain mitochondrial fraction with guanidine chloride inhibits markedly the stimulatory effect of all the stimulators used, but their joint addition almost abolishes the potentiating effect. In the presence of glutamic acid, due to the increase of the cooperative effect between the two stimulators, glutaminase activity is greatly increased and sometimes its inhibitory effect is not even observed. The data obtained indicate that in brain glutamic acid in the presence of phosphate+thyroxine cannot be considered as an inhibitor of glutaminase and that the important factor here is not so much the absolute levels of the activators as their favorable combinations.
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PMID:[Effect of glutamic acid on the interrelationship of the effects of different activators of cerebral glutaminase]. 1 7

Preliminary results are given on transport of glycine and L-glutamate into human cerebral tissue, normal and tumoral. In comparison with normal tissue, glycine transport is diminished in meningioma and oligodendroblastoma, unaffected in neurinoma, sharply increased in medulloblastoma. Glutamic acid transport is lowered in neurinoma and oligodendroblastoma; increased in medulloblastoma. Such preliminary observations are briefly discussed.
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PMID:[Accumulation of glutamic acid and glycine in human cerebral tumors in vitro]. 22 67

1. Glutamic acid showed a significant decrease during hibernation in brain cortex. This is attributed to: (a) Transformation to glutamine to detoxicate ammonia. (b) The synthesis of GABA from glutamic acid. (c) It is suggested that the enzyme GAD is active during hibernation. 2. GABA showed a significant increase in liver and brain cortex. It was absent in the blood serum. (a) The present results show that non-neural tissues contain lower GABA than neural tissues. (b) GABA may be formed locally in tissues by decarboxylation of glutamate as well as from pathways connected with tricarboxylic acid cycle. 3. Aspartic acid showed increased levels in blood serum, liver and brain cortex, the greatest increase was observed in liver. 4. A significant increase was recorded in the level of arginine in brain cortex and liver, whilst a smaller percentage increase was recorded in ornithine level. It is assumed that transformation of arginine to ornithine was depressed during hibernation.
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PMID:Metabolism of hibernating reptiles. Changes of free amino acids in blood, liver and brain. 31 10

Glutamic acid content of semen was determined photometrically in over 400 semen specimens. Glutamatic acid content was found to increase proportionately to temperature in the first few hours post ejaculation. The glutamate estimation should therefore be performed on semen at 30 min. after ejaculation. The frequency distribution of glutamic acid concentration with 400 unselected specimens, 50 "normozoospermias" as well as 42 azoospermias is shown. The mean value of normozoospermias was 10.6 mg% (+/- 4.6 mg%) that of azoospermias 7.7 mg% (+/- 4.7 mg%). There was no correlation found between glutamic acid content and pH value. A correlation however, was demonstrated between glutamic acid and following: sperm count, citrate concentration, gamma-GT and carnitine. No correlation to fructose content was detectable. That suggests that glutamate gets to the ejaculate with the secretions from the prostate gland and epididymis whereas the seminal vesicles do not play a role in the level in the total semen.
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PMID:Glutamic acid concentration in human semen--its origin and significance. 51 74

[3H]Glutamic acid (PCA) was followed with time after a single subcutaneous injection. PCA specific activity increased slowly, reaching a peak at 3 to 4 days after injection of the labeled amino acid, after which it slowly decline. Incorporation of [3H]glutamic acid into epidermal PCA was markedly inhibited by a single topical application of cycloheximide. Topical application of cycloheximide 2 hr prior to [3H]glutamate injection caused a significantly greater reduction in PCA specific activity (determined 3 days after injection) than cycloheximide treatment 3 hr after administration of the labeled amino acid. Ninety-seven percent of the PCA content of hairless mouse epidermis was shown to reside in the stratum corneum. These observations indicate the involvement of protein synthesis in the formation of PCA from glutamic acid rather than a direct conversion of the amino acid. The high level of PCA in mammalian epidermis appears to be caused by its accumulation in the stratum corneum accompainied by a relatively slow rate of PCA turnover in comparison to other tissues.
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PMID:Biosynthesis of pyrrolidone carboxylic acid in hairless mouse epidermis. 87 May 63

Glutamic acid diethylester (GDEE) reversibly antagonized excitations produced by glutamate and aspartate but not those produced by acetylcholine when applied iontophoretically to rat CA1 hippocampal neurons in penthrane (methoxyfluorane) anesthetized rats and to CA1 neurons in in vitro slice preparations. GDEE did not appear to differentiate between the excitations produced by glutamate aspartate and appeared to be a more potent antagonist than has previously been reported. CA1 cells were remarkably sensitive to acetylcholine; 5-50 nA being sufficient to produce marked amino acid-like excitations, which were unrelated to the pH of the acetylcholine. The nature of the responses to applied substances was virtually identical between the intact animal and the in vitro slice preparation. A description of the in vitro technique is given as an Appendix.
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PMID:GDEE antagonism of iontophoretic amino acid excitations in the intact hippocampus and in the hippocampal slice preparation. 126 Apr 58

Although various neurological diseases occur in patients with inborn error of metabolism of amino acids, amino acids also act as neurotransmitters. Glutamic acid, aspartic acid and glycine play roles as an excitatory neurotransmitter, but exert a neurodegenerative effect in case of the excessive release. Extensive studies have recently been performed on glutamate receptors, especially N-methyl-D-aspartate (NMDA) receptor in the hippocampus. Alzheimer brain shows a decreased number of NMDA receptors in the frontal cortex. The parkinsonian changes caused by MPTP is abolished by the administration of a NMDA antagonist. gamma-Aminobutyric acid (GABA) acts as an inhibitory amino acid. The content of GABA is low in the striatum of patients with Huntington's disease. The number of NMDA receptor is decreased also in Huntington striatum. These observations may give a clue for the prevention of various neurodegenerative diseases.
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PMID:[Amino acid metabolism in neurodegenerative diseases]. 135 3

A simple procedure for the measurement of gamma-glutamyl hydrolase (conjugase) activity is described. Glutamic acid released from pteroylpenta-gamma-glutamate by hog kidney and chicken pancreas conjugases was quantitated using the dye 4,4'-bis(dimethylamino)benzophenone hydrazone. The procedure involves hydrolysis of the folylpoly-gamma-glutamate substrate by conjugase, conversion of glutamate to alpha-ketoglutarate by L-glutamate dehydrogenase and colorimetric measurement of the BDBH derivative of alpha-ketoglutarate. The release of as little as one nmol of glutamic acid from the substrate can be measured by this procedure, which is well suited for the assay of a variety of conjugase preparations. In addition, the method should provide a general assay for the enzymatic hydrolysis of various folate and antifolate polyglutamates.
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PMID:A rapid colorimetric assay for gamma-glutamyl hydrolase (conjugase). 136 32

In vitro experiments the effect of chlorfenvinphos on aminotransferases activities in rat plasma and liver homogenate cytoplasmic fraction was studied. As amino groups donors in the transamination reactions with plasma enzymes the next eight amino acids were used: alanine, aspartic acid, cysteine, phenylalanine, leucine, lysine, valine and asparagine, and with the liver cytoplasmatic enzymes--the same above mentioned without asparagine. In all these reactions as an amino groups acceptor alfa-ketoglutaric acid was used. To the incubation mixtures were added: 1 cm3 of the plasma or liver homogenate cytoplasmic fraction; 0.05 cm3 of chlorfenvinphos solution in ethyl acetate (0.17 mg/cm3) or 0.05 cm3 ethyl acetate. Aminotransferase activity was expressed as the amount of glutamate developing during 1 h incubation. Glutamic acid was determined spectrophotometrically after chromatographic separation on filter paper. Both in rat plasma and in liver cytoplasmic fraction all used amino acids as amino groups donors in the transamination reactions were shown. In the reactions with the blood plasma enzymes the most active donors were: alanine, aspartic acid and cysteine and with the participation of liver transaminases: alanine, aspartic acid and phenylalanine. As well in plasma, as in liver the greater activity of AlAT than of AspAT was observed. In the reaction with alanine and aspartate there was formed in the case of plasma 1.51 mumol Glu/cm3 and 1.00 mumol Glu/cm3 respectively and in the case of liver -69.07 mumol Glu/g and 53.26 mumol Glu/g respectively. Results of statistical analysis revealed that small plasma and liver aminotransferases inhibition was caused by the solvent, while the insecticide under test had no influence on the efficiency of transamination.
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PMID:[Examination of the effect of chlorfenvinphos on the activity of aminotransferase in plasma and liver in vitro]. 146 57


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