Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.3.1 (citrate synthase)
 4,488 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

8 male patients (age 65-82 years) suffering from bacterial pneumonia or erysipelas were subjected to skeletal muscle biopsies. Significantly lower activities of lactate dehydrogenase (LDH) and glyceraldehyde-3-phosphate dehydrogenase (TPD) of skeletal muscle were recorded in the acute phase of the illness as compared to after the end of the convalescent phase. For citrate synthetase (CS) a similar although non-significant tendency was observed, while cytochrome c oxidase (CYTOX) was not altered by infection. Similar results have been reported in young patients with viral and mycoplasma infections. In the old patients the activity of LDH was approximately half of that found in the young patients (and in young controls confined to bed) on all occasions of measurement.
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PMID:Human skeletal muscle in bacterial infection: enzyme activities and their relationship to age. 19 74

A method for a 50-60-fold purification of a cysteine proteinase from trophozoites of Entamoeba histolytica using 35-80% ammonium sulphate fractionation, gel chromatography on Sephadex G-75, and preparative isoelectric focusing is described. The enzyme was examined for its proteolytic potencies towards native enzyme substrates. The amebic proteinase directly inactivates aldolase and glyceraldehyde-3-phosphate dehydrogenase from rabbit muscle as well as glucose-6-phosphate dehydrogenase from yeast. The inactivation of citrate synthase from porcine heart proceeds rather slowly, whereas malate dehydrogenase from porcine heart is not affected by the amebic proteinase under the condition used. With the exception of aldolase all inactivated enzyme substrates have been cleaved by limited proteolyses yielding major cleavage products. The inactivation of aldolase probably functions by the release of a small segment from a terminus being essential for aldolase activity.
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PMID:Cysteine proteinase of Entamoeba histolytica. I. Partial purification and action on different enzymes. 287 Apr 30

This paper presents a study of the metabolic and contractile types of 34 samples from 30 muscles in five crossbred Pietrain-Large White pigs 6 to 7 months old. The activity of the following enzymes was measured: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), lactate dehydrogenase using high (LDH-h) or low (LDH-b) pyruvate concentrations in the reaction medium, citrate synthase (CS), and myofibrillar Ca-Mg activated ATPase. Haeminic iron and ultimate pH (pHu) were measured on the same samples. The results showed a negative, rather linear relationship between GAPDH, LDH and ATPase activities on the one hand and CS and haeminic iron on the other. Rather high correlations (r = 0.7 to 0.8) were observed between metabolic and contractile criteria and pHu; the red (slow) muscles had the highest pHu.
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PMID:[Enzyme metabolic and contractile activities of 30 pig muscles. Relation with the final ph attained after death]. 293 86

We determined representative enzyme activities of glycogenolysis (glycogen phosphorylase) glycolysis (d-glyceraldehyde-3-phosphate dehydrogenase, GAPDH), beta oxidation of free fatty acids (1-3-hydroxyacyl CoA dehydrogenase, HADH), citric acid cycle (citrate synthase, CS), lactate fermentation (lactate dehydrogenase LDH), and creatine phosphate metabolism (creatine kinase, CK) in left ventricular samples of 36 patients to investigate if the metabolic capacities of the energy-supplying pathways are differently affected in different heart diseases. There were 17 patients with mitral valve diseases (MVD), 8 patients with aortic valve diseases (AVD), and 11 patients who suffered from dilative cardiomyopathies (DCM). The main metabolic characteristic on the level of enzymatic organization in patients with DCM was an increased ratio of GAPDH/HADH activities and a decreased ratio of HADH/CS activities compared to the valve-diseased patients. This result indicates that the capacity of glucose oxidation is enhanced at the expense of fatty acid metabolism in patients with DCM. Furthermore, we determined significantly lower myocardial CK activities in this group of patients, most probably reflecting a diminished content of myofibrils. Citrate synthase activity was lowest in patients with AVD. Although we cannot rule out that the impaired left ventricular function is in part responsible for the shift of the capacities of the energy-supplying metabolism in patients with DCM, we favor the assumption that it is a specific feature of this myocardial disease.
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PMID:Comparative analysis of myocardial enzyme activities of the energy-supplying metabolism in patients with dilative cardiomyopathies and valve diseases. 370 46

Crude extracts of both vegetative cells and glycerol-induced microcysts of Myxococcus xanthus contained the following enzyme activities: phosphofructokinase, phosphoglucoisomerase, fructose-1,6-diphosphatase, fructosediphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, phosphopyruvate carboxylase, citrate synthase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and uridine diphosphate glucose pyrophosphorylase. With the exception of isocitrate dehydrogenase, which was present at a fivefold higher concentration in microcysts, all activities in extracts from both types of cells were essentially equal. Hexokinase and pyruvate kinase could not be detected in extracts from either type of cell. Microcysts metabolized acetate at a lower rate than did vegetative cells. Most of this decrease was reflected in a substantial decrease in ability of microcysts to oxidize acetate to CO(2). In addition, microcysts and vegetative cells showed a different distribution of (14)C-label from incorporated acetate.
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PMID:Comparative intermediary metabolism of vegetative cells and microcysts of Myxococcus xanthus. 430 96

The purpose of the study was to verify the influence of several weeks of chronic low-frequency electrical stimulation (LFES) on the metabolic profile and functional capacity of human skeletal muscle. Knee extensor muscles (KEM) of eight subjects were electrically stimulated at 8 Hz for 8 h/day and 6 days/wk. Vastus lateralis muscle samples were taken before, after 4 wk, and after 8 wk of LFES, and activities of anaerobic (creatine kinase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase) and aerobic-oxidative (citrate synthase, 3-hydroxyacyl-CoA dehydrogenase, cytochrome-c oxidase) enzyme markers were determined. KEM dynamic performance was also assessed before, after 4 wk, and after 8 wk of LFES. Activity levels of anaerobic enzymes were not altered, whereas the activity levels of citrate synthase (29%),3-hydroxyacyl-CoA dehydrogenase (22%), and cytochrome-c oxidase (25%) were significantly increased after 4 wk of LFES but were not further increased after 4 additional wk of LFES. KEM performance was also improved (P < 0.05) but leveled off after 4 wk of LFES. Although significant changes were observed, the results of the present study suggest that the muscle characteristics investigated in the current study have a limited capacity of adaptation in response to this form of chronic LFES.
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PMID:Human skeletal muscle adaptation in response to chronic low-frequency electrical stimulation. 783 13

We previously found that intermittent hyperbaric oxygen exposure increases metabolic enzyme activity in soleus muscle. Since the metabolic enzyme activities of the heart and diaphragm of healthy animals are difficult to alter, we questioned whether intermittent hyperbaric oxygenation would provide a stimulus sufficient to increase metabolic enzyme activity. Therefore, we exposed 36 rabbits (4 groups of 9) twice daily for 90 min 5 days/wk to either 100% O2 at 243 kPa, 8.5% O2, and 91.5% N2 at 243 kPa, 100% O2 at 101 kPa, or 21% O2 at 101 kPa. After 4 wk of treatment, the activities of citrate synthase, succinate dehydrogenase, alpha-glycerophosphate dehydrogenase, phosphofructokinase, and glyceraldehyde-3-phosphate dehydrogenase were measured. In both the heart and the diaphragm, none of the treatments significantly altered the mean enzyme activities for any of the enzymes measured. Therefore, it seems that the hyperbaric oxygenation treatment protocols used do not induce an increase in metabolic enzyme activity in the heart and diaphragm in healthy animals.
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PMID:Hyperbaric oxygenation treatments and metabolic enzymes in the heart and diaphragm. 806 60

In this paper, we demonstrate the ability of liquid-liquid partition chromatography (LLPC) to detect conformational alterations occurring in well-characterized enzymes. The conformational changes induced in dehydrogenases such as alcohol dehydrogenase (ADH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), lactate dehydrogenases (LDH) and malate dehydrogenase (MDH) upon binding of ligand(s) were detectable by LLPC. The ligand-dependent equilibrium between two forms of citrate synthase (CS), glutamate-oxaloacetate transaminase (GOT), hexokinase (HK) and 3-phosphoglycerate kinase (PGK) could also be demonstrated. Furthermore, different conformational forms of some of the apoenzymes could also be detected and separated by LLPC. The results obtained here are discussed in relation to those obtained by other methods.
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PMID:Enzyme conformational alterations detected by partition column chromatography. 879 88

To investigate effects of sustained activity on major phenotypic properties, the left extensor digitorum longus muscle of young (15 wk) and aging (101 wk) male Brown Norway rats was subjected to 50 days of chronic low-frequency stimulation (CLFS; 10 Hz, 10 h/day). The contralateral muscle served as control. Changes in metabolic enzymes were analyzed by using glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase as reference enzymes of glycolysis and by using citrate synthase and 3-hydroxyacyl-CoA dehydrogenase as mitochondrial enzymes representative of aerobic-oxidative metabolism. Myosin heavy chain (MHC) isoforms were analyzed by SDS-PAGE. No differences existed between the enzyme activity profiles of control muscles from young and aging rats. CLFS induced similar increases in mitochondrial enzymes, as well as similar decreases in glycolytic enzymes. Although the MHC composition of the control muscles in the aging rats displayed a shift toward slower isoforms, the ultimate changes induced by CLFS led to nearly identical MHC phenotypes in both young and aging rats. These results demonstrate an unaltered adaptability of skeletal muscle to increased neuromuscular activity in the aging rat.
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PMID:Identical responses of fast muscle to sustained activity by low-frequency stimulation in young and aging rats. 968 17

The addition of cyclosporin A (500 ng ml(-1)) - an inhibitor of the Ca2+-calmodulin-regulated serine/threonine phosphatase calcineurin - to primary cultures of rabbit skeletal muscle cells had no influence on the expression of fast myosin heavy chain (MHC) isoforms MHCIIa and MHCIId at the level of protein and mRNA, but reduced the expression of slow MHCI mRNA. In addition, no influence of cyclosporin A on the expression of citrate synthase (CS) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA was found. The level of enzyme activity of CS was also not affected. When the Ca2+ ionophore A23187 (4 x 10(-7) M) was added to the medium, a partial fast-to-slow transformation occurred. The level of MHCI mRNA increased, and the level of MHCIId mRNA decreased. Cotreatment with cyclosporin A was able to prevent the upregulation of MHCI at the level of mRNA as well as protein, but did not reverse the decrease in MHCIId expression. The expression of MHCIIa was also not influenced by cyclosporin A. Cyclosporin A was not able to prevent the upregulation of CS mRNA under Ca2+ ionophore treatment and failed to reduce the increased enzyme activity of CS. The expression of GAPDH mRNA was reduced under Ca2+ ionophore treatment and was not altered under cotreatment with cyclosporin A. When the myotubes in the primary muscle culture were electrostimulated at 1 Hz for 15 min periods followed by pauses of 30 min, a partial fast-to-slow transformation was induced. Again, cotreatment with cyclosporin A prevented the upregulation of MHCI at the level of mRNA and protein without affecting MHCIId expression. The nuclear translocation of the calcineurin-regulated transcription factor nuclear factor of activated thymocytes (NFATc1) during treatment with Ca2+ ionophore, and the prevention of the translocation in the presence of cyclosporin A, were demonstrated immunocytochemically in the myotubes of the primary culture. The effects of cyclosporin A demonstrate the involvement of calcineurin-dependent signalling pathways in controlling the expression of MHCI, but not of MHCIIa, MHCIId, CS and GAPDH, during Ca2+ ionophore- and electrostimulation-induced fast-to-slow transformations. The data indicate a differential regulation of MHCI, of MHCII and of metabolism. Calcineurin alone is not sufficient to mediate the complete transformation.
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PMID:Calcineurin regulates slow myosin, but not fast myosin or metabolic enzymes, during fast-to-slow transformation in rabbit skeletal muscle cell culture. 1135 Oct 29


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