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)

The mitochondrial matrix subfractions from rat liver, kidney cortex, brain, heart, and skeletal muscle were isolated and their protein components were resolved by two-dimensional polyacrylamide gel electrophoresis, revealing between 120 and 150 components for each matrix subfraction. Excellent resolution was obtained utilizing a pH 5 to 8 gradient in the first dimension and in 8 to 13% exponential acrylamide gradient in the second dimension, increasing the number of mitochondrial matrix proteins observed 3-fold over one-dimensional systems. Protein components tentatively identified by co-migration with pure enzymes and by known tissue distributions are carbamoyl-phosphate synthetase (EC 2.7.2.5), ornithine transcarbamylase (EC 2.1.3.3), glutamate dehydrogenase (EC 1.4.1.3), pyruvate carboxylase (EC 6.4.1.1), citrate synthase (EC 4.1.3.7), fumarase (EC 4.2.1.2), aconitase (EC 4.2.1.3), alpha-ketoglutarate dehydrogenase (EC 1.2.4.2), dihydrolipoyl transsuccinylase (EC 2.3.1.12), lipoamide dehydrogenase (EC 1.6.4.3), glutamate-aspartate aminotransferase (EC 2.6.1.1), and the two subunits of pyruvate dehydrogenase (EC 1.2.4.1). Protein components unambiguously identified by peptide mapping are citrate synthase, aconitase, and pyruvate carboxylase. The inner membrane subfraction from rat liver mitochondria was also resolved two dimensionally; the alpha and beta subunits of ATPase (F1) (EC 3.6.1.3) were identified by peptide mapping.
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PMID:Resolution of rat mitochondrial matrix proteins by two-dimensional polyacrylamide gel electrophoresis. 44 63

The activity of lipoamide dehydrogenase and two closely related enzymes was studied simultaneously in early, mild, and late passage fibroblast cultures. Friedreich's ataxia fibroblasts tended to lose pyruvate dehydrogenase and citrate synthase activities, while lipoamide dehydrogenase activity remained constant with aging of the cells. Mean pyruvate dehydrogenase activity was lower over-all in fibroblasts from ataxics. Mean citrate synthase activity was higher in ataxic fibroblasts. Present tissue culture media do not represent the best conditions in which to reproduce cofactor binding defects such as those found in other genetic diseases with structural enzyme mutations.
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PMID:Pyruvate dehydrogenase, lipoamide dehydrogenase and citrate synthase activity in fibroblasts from patients with Friedreich's and Charlevoix-Saguenay ataxia. 48 17

The oxidative capacity of skeletal muscle fibre types was evaluated histochemically using the nicotinamide dinucleotide diaphorase (NADH-D) staining, and biochemically by measuring the activity of citrate synthase (CS) in both whole muscle samples and in pools of fibres of identified type. Duplicate determinations of the NADH-D staining pattern resulted in standard deviations (sd) between duplicates of 6 and 11 per cent for two observers. The NADH-D pattern was found to differ between observers. Duplicate determinations of CS activity in the same fibre pools resulted in an sd value of 2.9 mumol/g/min. Measurements of whole muscle CS activity did not provide information about the distribution of oxidative capacity among fibre types. The NADH-D stain and CS activity in fibre pools both showed that, in general, type I and IIA fibres had a higher oxidative capacity than type IIB fibres. Biochemical techniques also showed, however, that the CS activity in type I and IIA fibres of different horses could vary as much as twofold, whereas the NADH-D rating showed a high intensity staining for most type I and IIA fibres in all horses. Furthermore, type IIB fibres received a lower NADH-D rating than the other fibre types even when the CS activities were quite similar. For purposes of research, biochemical measurement of oxidative capacity in individual muscle fibre types provides valuable quantitative and comparative information. The ease of histochemical NADH-D staining in comparison to fibre dissections makes this technique more practical for routine estimates of the distribution of oxidative capacity among muscle fibres.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oxidative capacity of skeletal muscle fibres in racehorses: histochemical versus biochemical analysis. 316 90

The subcellular distribution of the mitochondrial enzymes lipoamide dehydrogenase (LIPDH), citrate synthase (CS), and beta-hydroxyacyl-CoA-dehydrogenase (HADH) in bovine and porcine liver tissue was studied by measuring the enzyme activities in a phosphate buffer extract of tissue (total activity) and in liver press-juice (cell plasma). In slaughter-fresh liver most of the activity was located in the mitochondria. During storage of liver under refrigeration (+2 degrees C) for several days a large decrease in total LIPDH activity and a lesser decrease in HADH activity, but no change in CS activity were observed. There was no or only little release of the three enzymes into the cell plasma during storage; this indicates that storage of liver at +2 degrees C was not accompanied by a marked damage of mitochondria. Freezing (-20 degrees C) and thawing of bovine and porcine liver caused some losses of the total activity of HADH and particularly of LIPDH but not changes in CS activity. There was a considerable increase in the activities of LIPDH, CS, and HADH in the press juice after freezing and thawing of liver tissue. Apparently freezing of liver results in damage to the mitochondria and, therefore, in a partial release of the three enzymes from the inner membrane of the mitochondrion into the cell plasma. By storage of liver under refrigeration the mitochondria became more sensitive to freezing and thawing. Prolonged frozen-storage of liver resulted in an increased release of LIPDH, CS, and HADH into the cell plasma.
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PMID:[Effect of cold storage and freezing of bovine and porcine liver on activity and subcellular distribution of mitochondrial enzymes]. 359 Sep 94

Freezing of bovine, calf, and porcine skeletal muscles at -20 degrees C before or after rigor mortis and thawing at room temperature did not cause significant changes in the total activities of the mitochondrial enzymes lipoamide dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA-dehydrogenase. Freezing (pre or post rigor) and thawing result in a partial release of these enzymes from their binding to the inner membrane of the mitochondria. The transfer of enzyme activity into the sarcoplasmic fluid is due to damage of the mitochondrial membranes by freezing and thawing of the muscle tissue. During longer storage of the muscle at +2 degrees C the mitochondria become more labile towards freezing which may be recognised from an increased release of the enzymes (particularly in porcine muscle). Repeated freeze/thaw cycles cause an increase in the release of the three enzymes.
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscles. VI. Influence of freezing (-20 degrees C) and thawing of bovine, calf and porcine muscle on activity and subcellular distribution]. 384 Mar 10

Freezing at -20 degrees C and subsequent thawing of muscles from sheep, hare and deer, and of breast and leg muscle from chicken and duck, did not result in significant changes of the total activity of the enzymes citrate synthase and beta-hydroxy-acyl-CoA-dehydrogenase; lipoamide dehydrogenase seemed to be somewhat more labile. Freezing and thawing of muscle tissue caused a partial release of these three mitochondrial enzymes into the sarcoplasmic fluid which indicates similar freeze-damage of the inner membrane of the mitochondria to that observed with bovine and porcine muscles.
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscles. VII. The influence of freezing (-20 degrees C) and thawing of muscles from sheep, game and poultry on activity and subcellular distribution]. 384 Mar 11

Samples of bovine muscle (post rigor) were frozen at different temperatures between -5 degrees and -196 degrees C at different freezing rates, and thawed at room temperature. The activities of the mitochondrial enzymes lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase were determined in the supernatant of the tissue homogenates in phosphate buffer (total enzyme activity), as well as in the press juice of the intact tissue (enzyme activity in the sarcoplasma). Neither the temperature nor the rate of freezing (varying from 25.5 to 0.01 min/degrees C) showed a significant influence on the total enzyme activities. Freezing at -5 degrees and -10 degrees C (at different rates but without intracellular freezing) and thawing did not result in an appreciable release of enzymes. Below -10 degrees C the release of the three enzymes from their binding to the inner membrane of the mitochondrion into the sarcoplasmic fluid increased upon rapid freezing with decreasing temperature i.e. with increasing intracellular ice formation, whereas at slow freezing (with extracellular ice formation only) freezing below -20 degrees C did not cause further enzyme release. At freezing temperatures below -20 degrees C rapid freezing resulted in a significantly stronger release of the three enzymes than slow freezing. From these results it was concluded that the damage to mitochondrial membranes upon fast freezing is primarily a result of intracellular (and perhaps also intramitochondrial) ice formation, whereas the membrane damage during slow freezing is primarily due to dehydration caused by the migration of water from the muscle fibers into the extracellular space as a result of osmotic effects. Ion concentration in the nonfreezing fraction of tissue water seems to be only of minor importance for the disintegration of mitochondrial membranes.
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle. VIII. The influence of temperature and rate of freezing of bovine muscle on the activity and subcellular distribution of the enzymes in the thawed tissue]. 384 Mar 12

Samples of bovine muscle (post rigor) were frozen at -30 degrees C at two different rates (1.27 min/degrees C and 13.10 min/degrees C) and thawed at different rates between 1.6 (22 degrees C) and 430 min/degrees C (0 degrees C). The activities of the mitochondrial enzymes lipoamide dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA-dehydrogenase were determined in the supernatant of the tissue homogenate in phosphate buffer (total activity) and in the press juice of the intact tissue (activity in the sarcoplasma). The rate of thawing did not show a significant influence on total enzyme activities. In most cases, however, slow thawing caused a greater release of the enzymes from the mitochondria into the sarcoplasmic fluid than fast thawing, this effect being apparently independent of the rate of freezing. The greater damage to mitochondrial membranes upon slow thawing cannot be due to a longer exposure of the muscle cell to increased ionic strength in the non-freezable part of the cell water at the "critical" temperature around -3 degrees C because freezing of muscle samples at -3 degrees C and incubating them at -3 degrees C for five days resulted neither in changes of the total enzyme activities nor in a release of the three mitochondrial enzymes. From these results it is concluded that the influence of thawing rate on the damage to muscle mitochondria is probably not due to ionic effects or to recrystallization phenomena in the ice phase.
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle. IX. The influence of the rate of thawing on activity and subcellular distribution in fast and slow frozen bovine muscle]. 384 Sep 38

The influence of storage of bovine and porcine muscle at -20 degrees C for 12 months and of thawing on the total extractable activity and subcellular distribution (activities in the supernatant of a phosphate buffer extract and in the press juice of the thawed tissue) of the mitochondrial enzymes lipoamide dehydrogenase (LIPDH), citrate synthase (CS) and beta-hydroxyacyl-CoA-dehydrogenase (HADH) was studied. The total activity of LIPDH decreased during frozen storage whereas the activities of CS and HADH did not change appreciably. From the increase of CS and HADH activities in the muscle press juice it was concluded that--additionally to the effect of freezing and thawing itself--frozen storage results in further damage to the inner membrane of muscle mitochondria, which may be recognized from the increased release of membrane-bound enzymes. In this respect porcine muscle mitochondria seem to be more sensitive than bovine muscle mitochondria.
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PMID:[Lipoamide dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscles. X. The influence of frozen storage of bovine and porcine muscle on activity and subcellular distribution]. 384 Sep 39

Frozen storage at -20 degrees C for three months and thawing of muscles from sheep, hare and deer, and of the breast and leg muscles from chicken and duck did not result in significant changes in the extractable total activities of the mitochondrial enzymes citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase; however there was a decrease in the total activity of lipoamide dehydrogenase except in the chicken leg muscle, where such a decrease did not occur. From the increase in the activities of the three enzymes in the muscle press juice it was concluded that - additionally to the effect of freezing and thawing itself - frozen storage results in further damage to the inner membrane of muscle mitochondria which is signalled by the release of membrane-bound enzymes. Chicken muscle mitochondria seem to be more stable against frozen storage of the tissue than the mitochondria in the muscles of the other species studied (including bovine and porcine muscle).
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase of skeletal muscle. 9. Influence of frozen storage of musculature of sheep, game and poultry on activity and subcellular distribution]. 384 Sep 40


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