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

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Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two strains of Cyanidium caldarium, one able to utilize nitrate as a substrate, and the other not, were tested for the presence of enzymes of ammonia assimilation. The nitrate-assimilating strain exhibits glutamate dehydrogenase activity. By contrast, the other strain lacks glutamate dehydrogenase; it possesses high alanine dehydrogenase and L-alanine aminotransferase activities which suggest that this strain may incorporate ammonia through reductive amination of pyruvate and may form glutamate from 2-ketoglutarate by a transamination reaction with alanine. Neither strain reveals glutamate synthase activity. Both strains contain similar levels of glutamine synthetase.
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PMID:Observations on enzymes of ammonia assimilation in two different strains of Cyanidium caldarium. 24 91

D-Vinylglycine (2-amino-3-butenoate) functions as a transamination substrate and irreversible inactivator of the homogeneous pyridoxal phosphate-dependent D-amino acid transaminases from Bacillus subtilis and Bacillus sphaericus. In the absence of alpha-ketoglutarate as co-substrate, vinyl-glycine causes little if any inactivation of either enzyme; in the presence of excess alpha-ketoglutarate, both enzymes are inactivated with pseudo-first order kinetics. The limiting rate constant for inactivation of the B. sphaericus enzyme is 1.9 min-1, for the B. subilis enzyme it is 0.36 min-1. The number of catalytic events before inactivation is about 450 for the B. sphaericus enzyme and about 800 for the B. subtilis enzyme; that is, about 0.2% inactivation in each catalytic cycle for the former enzyme and 0.15% for the latter. Comparisons are made with the L-aspartate amino-transferase from pig heart which is inactivated completely in one catalytic cycle and the L-alanine aminotransferase which is not inactivated in many cycles. Comparisons are also made between the likely mode of D-transaminase inactivation produced by vinylglycine and the mode of inactivation induced by beta-chloro-D-alanine.
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PMID:Inactivation of bacterial D-amino acid transaminases by the olefinic amino acid D-vinylglycine. 40 67

The administration of L-cycloserine to mice resulted in a dramatic decrease in the activities of 4-aminobutyrate:2-oxoglutarate aminotransferase (GABA-T) and L-alanine:2-oxoglutarate aminotransferase (ALA-T) in both brain and liver. L-Aspartate:2-oxoglutarate aminotransferase was inhibited only slightly, and brain glutamic acid decarboxylase not at all. Liver ALA-T activity returned to near normal levels within 24 h of L-cycloserine administration whereas liver GABA-T and brain ALA-T activities had returned only halfway to normal levels in the same time period. The recovery in the activity of brain GABA-T was even slower. A consequence of the inhibition of brain GABA-T activity was an elevation in the GABA content of the tissue which was maximal 3 h after L-cycloserine administration and which was still noticeable 8 h after the drug treatment. L-Cycloserine was also a potent in vitro inhibitor of brain GABA-T activity. The inhibition was competitive with respect to GABA, the Ki value being 3.1 X 10(-5) M. The prior administration of L-cycloserine to mice significantly delayed the onset of isonicotinic acid hydrazide induced convulsions.
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PMID:Effect of L-cycloserine on brain GABA metabolism. 63 58

A trial was performed in 204 healthy calves (heifers) of the Bohemian Spotted breed in the post-natal period from birth to the age of four months. The activities of the following enzymes in blood plasma were determined: L-aspartate: 2-oxoglutarate: aminotransferase, EC.2.6.1.1. (GOT), L-alanine: oxoglutarate: aminotransferase, EC.2.6.1.2. (GPT), L-lactate: NAD oxidoreductase, EC.1.1.1.27 (LDH), and orthophosphoric acid monoester phosphohydrolase, EC.3.1.3.1. (alkaline phosphatase). The calves were divided into age categories according to the date of birth with an interval of one week. GOT activity in blood plasma increased significantly until the age of eight weeks (from the original value of 1.1708 +/- 0.2598 micronmol ml-1 to 1.8150 +/- 0.6362 micronmol ml-1, with the maximum of 2.0317 +/- 0.7777 micronmol ml-1 of plasma in the sixth week). In the subsequent period the GOT curve has not a characteristic course. While the activity of GOT increased in the first weeks after birth, the activity of GPT showed a significant drop (from the original level of 0.9000 +/- 0.3364 micronmol ml-1 to the minimum of 0.3675 +/- 0.1901 micronmol ml-1 of plasma in the seventh week); from the 10th week on the values rise so that at the end of the period of study they reach almost the same levels as in calves in the first postnatal week. The activity of LDH in blood plasma remains at almost the same level in the first five weeks after birth (between 43.4025 +/- 8.4893 micronmol ml-1 and 46.3792 +/- 14.8952 micronmol ml-1 of plasma); it was at a statistically significantly higher level only in a short period between the 7th and 10th week after birth. The highest values of alkaline phosphatase in blood plasma were recorded at the age of two or three weeks (maximum in the second week 23.9833 +/- 9.0945 micronmol ml-1 of plasma); from the fourth week on, the values of alkaline phosphatase are significantly lower until the end of the test period, ranging betweek 5.3133 +/- 1.6017 micronmol ml-1 and 7.5425 +/- 2.2437 micronmol ml-1 of plasma. Changes conditioned by postnatal development were observed in the development of all the enzymatic activities under study, the greatest changes being observed in alkaline phosphatase.
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PMID:[The development of transaminase activity (SGOT and SGPT), lactate dehydrogenase and alkaline phosphatase in the blood plasma of calves up to the age of 4 months]. 82 94

Incubation of rat brain 4-aminobutyrate aminotransferase with 4-amino-hex-5-enoic acid, a substrate analog of 4-aminobutyric acid, results in a time-dependent irreversible loss of enzymatic activity. In the presence of 0.1 mM inhibitor the half-life of the inactivation process is approximately 6 min. Low concentrations of L-glutamic acid or 4-aminobutyric acid protect against this inactivation, while 2-oxoglutarate prevents this protection, suggesting that only the pyridoxal form of the enzyme is susceptible to inhibition by 4-amino-hex-5-enoic acid. The irreversible inhibition of mammalian 4-aminobutyrate aminotransferase by 4-amino-hex-5-enoic acid is selective. There is no inhibition of this enzyme from Pseudomonas fluorescens with the inhibitor at mM concentrations. Even at 10 mM there is no irreversible inhibition of mammalian glutamate decarboxylase or of aspartate aminotransferase, while alanine aminotransferase is inhibited over 500 times more slowly than rat brain 4-aminobutyrate transaminase.
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PMID:4-amino-hex-5-enoic acid, a selective catalytic inhibitor of 4-aminobutyric-acid aminotransferase in mammalian brain. 85 82

1. Rats were given moderate-selenium (4-5 mg/kg) or low-Se (0-5 mg/kg) diets during gestation and lactation. Their young were given diets with high (10 mg/kg), moderate or low Se contents from weaning, and groups of rats were killed at intervals during the 14-week experimental peroid. 2. Compared with young rats which received the low-Se diet, those which received the moderate- or high-Se diets had a high incidence of liver lesions and there were changes in liver Se content, haemoglobin concentration, packed cell volume, prothrombin activity, fibrinogen content, spleen weight, body water and serum glutamic-oxaloacetic and glutamic-pyruvic transaminas (L-aspartate : 2-oxoglutarate aminotransferase; EC 2.6.1.1 and L-alanine : 2-oxoglutarate aminotransferase; EC 2.6.1.2 respectively) and alkaline phosphatase (EC 3.1.3.1) activities. In those rats which received the high-Se diet the changes were more pronounced than in those which received the moderate-Se diet. 3. In young rats from dams given moderate-Se diets, which were themselves given the moderate-Se diet, the liver Se content decreased continuously, whereas rats given the same diet but from dams which had received the low-Se diet, the liver Se content increased continuously. There was a slight improvement of symptoms of Se toxicity in all groups by the 5th week of the experimental peroid. 4. The results suggest that there was an adaptation to chronic Se intake.
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PMID:Effects of ingestion of organic selenium in adapted and non-adapted rats. 112 69

The activities of serum aspartate aminotransferase (EC 2.6.1.1, L-aspartate: 2-oxoglutartate aminotransferase, ASAT) and alanine aminotransferase (EC 2.6.1.2, L-alanine: 2-oxoglutarate aminotransferase, ALAT) were determined in the sera of 1484 apparently healthy subjects using kinetic methods according to the Scandinavian recommendation (33). In the adult sera the mean activity of ASAT was 21.4
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PMID:Activities of aspartate and alanine aminotransferases and alkaline phosphatase in sera of healthy subjects. 115 24

An attempt was made to determine the effect of steroidal contraceptives on the utilization of Vitamins-B1 and B6. Subjects, aged 22-38 years, were not taking any external source of vitamins. A 24-hour urine sample was collected and a fasting blood sample drawn for the estimation of erythrocyte amino-transferases and transketolase. Then each subject was given 2 gm of L-tryptophan. Another 24-hour urine specimen was then collected. Xanthurenic acid values in urine specimens were compared. Ovral or norgestrel was then given for 3 cycles. After these 3 cycles, blood collections and tryptophan load tests were repeated. Erythrocyte alanine aminotransferase (EAIT) and aspartates aminotransferases (EAsT) were measured. Also, erythrocyte transketolase (ETK) was estimated and the "TPP" effect determined by adding 75 mcg of thiamine pyrophosphate. of 11 women taking Ovral, 7 showed an abnormal response to the tryptophan load as shown by the xanthurenic acid excretion. Responses of all 11 women on norgestrel to tryptophan loads were normal. EAIT and EAsT tests were normal with both drugs (p more than .05). Erythrocyte transketolase activity was not significantly changed by either preparation (p more than .05). The increased xanthurenic acid excretion with Ovral after tryptophan load is thought to indicate Vitamin-B6 deficiency. Basal levels of ETK decreased in 7 of 10 women on Ovral but increased in 5 of 8 women on norgestrel therapy. Also, in vitro stimulation with TPP was observed in 4 of these women. The relation of this finding to Vitamin-B1 is not clear. Urinary thiamine, blood pyruvic acid, and alpha-ketoglutaric acid and transketolase activity require study to assess the Vitamin-B1 status under contraceptive therapy.
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PMID:Short-term effect of ovral and norgestrel on the vitamin B6 and B1 status of women. 119 31

The only exogenous substrates oxidized by mitochondria isolated from the flight muscle of the Japanese beetle (Popillia japonica) are proline, pyruvate and glycerol 3-phosphate. The highest rate of oxygen consumption is obtained with proline. The oxidation of proline leads to the production of more NH3 than alanine, indicating a functioning glutamate dehydrogenase (EC 1.4.1.2). Studies of mitochondrial extracts confirm the presence of a very active glutamate dehydrogenase, and this enzyme is found to be activated by ADP and inhibited by ATP. These extracts also show high alanine aminotransferase activity (EC 2.6.1.2) and a uniquely active "malic' enzyme (EC 1.1.1.39). The "malic' enzyme is activated by succinate and inhibited by ATP and by pyruvate. It is suggested that the input of tricarboxylate-cycle intermediate from proline oxidation is balanced by the formation of pyruvate from malate, and the complete oxidation of the majority of the pyruvate. Studies of the steady-state concentrations of mitochondrial CoASH and CoA thioesters during proline oxidation show a high succinyl (3-carboxypropionyl)-CoA content which falls on activating respiration with ADP. There is a concomitant rise in CoASH. However, the reverse transition, from state-3 to state-4 respiration, causes only very slight changes in acylation. The reasons for this are discussed. Studies of the mitochondrial content of glutamate, 2-oxoglutarate, malate, pyruvate, citrate and isocitrate during the same phases of proline oxidation give results consistent with control at the level of glutamate dehydrogenase and isocitrate dehydrogenase during proline oxidation, with the possibility of further control at "malic' enzyme. During the oxidation of pyruvate all of the tricarboxylate-cycle intermediates and NAD(P)H follow the pattern of changes described in the blowfly (Johnson & Hansford, 1975; Hansford, 1974) and isocitrate dehydrogenase is identified as the primary site of control.?2OAuthor
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PMID:The nature and control of the tricarboxylate cycle in beetle flight muscle. 120 Sep 85

Kynurenine transaminase activity in rat liver was found in both the mitochondrial and supernatant fractions. The mitochondrial and supernatant fractions contained (a) kynurenine pyruvate transaminase which showed a preference for pyruvate as amino-acceptor and a pH optimum between 8.0 and 8.5 and (b) kynurenine alpha-ketoglutarate transaminase with a preference for alpha-ketoglutarate and a pH optimum between 6.0 and 6.5.
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PMID:Subcellular distribution and properties of rat liver kynurenine transaminase. 124 13


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