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 citrate synthase of yeast was purified to homogeneity and shown to have a subunit molecular weight of 52,000. Antibodies were prepared to it in rabbits. Translation of total yeast mRNA using a reticulocyte lysate showed that [3H]leucine was incorporated into a protein precipitable by rabbit anti-yeast citrate synthase with a molecular weight of about 54,000. No incorporation of [35S]methionine into an anti-citrate synthase precipitable protein could be detected in a similar experiment. In vivo labeling of cells with 35SO4 did not result in the labeling of citrate synthase.
J Biol Chem 1982 Sep 25
PMID:In vitro translation of mRNA for yeast citrate synthase. 680 68

The catalytic activities of several oxidative and glycolytic enzymes were determined in the gastrocnemius muscle of 10 mammalian species differing in body weight by nearly 6 orders of magnitude. When expressed in terms of units gm-1, the activities of enzymes functioning in oxidative metabolism (citrate synthase, beta-hydroxybutyrylCoA dehydrogenase, and malate dehydrogenase) decrease as body weight increases. Log-log plots (activity gm-1 vs body mass) yield straight lines with negative slopes that are less than the allometric exponent (-0.25) typically observed for basal metabolic rates. Since the amount of power a muscle can generate depends upon the catalytic potential of its enzyme machinery (the higher the catalytic potential the higher the maximum rate of energy generation), these data predict that the scope for aerobic activity in large mammals should be greater than in small mammals if nothing else becomes limiting, a result in fact recently obtained by Taylor et al. (Respir. Physiol., 1981). In contrast to the scaling of oxidative enzymes, the activities of enzymes functioning in anaerobic glycogenolysis (glycogen phosphorylase, pyruvate kinase, and lactate dehydrogenase) increase as body size increases. Log-log plots (activity gm-1 vs body mass) display a positive slope indicating that the larger the animal the higher the glycolytic potential of its skeletal muscles. This unexpected result may indicate higher relative power costs for burst type locomotion in larger mammals, which is in fact observed in within-species studies of man. However, the scaling of anaerobic muscle power has not been closely assessed in between-species comparisons of mammals varying greatly in body size.
Respir Physiol 1981 Sep
PMID:Scaling of oxidative and glycolytic enzymes in mammals. 703 6

Adenine nucleotides were tested as effectors of peroxisomal and mitochondrial citrate synthase from Agave americana leaves in the presence of different concentrations of acetyl-CoA and oxalacetate substrates. ATP inhibited both enzyme activities but with a different inhibition profile. 1.0-7.5 mM ADP did not inhibit the peroxisomal citrate synthase in the presence of high substrate concentrations, while the mitochondrial enzyme was strongly inhibited by 1.0 mM ADP in the same conditions. Likewise, a different pattern was obtained with AMP on both peroxisomal and mitochondrial activities. The rate of citrate formation as function of acetyl-CoA and oxalacetate concentration was also studied in both fractions. Maximal velocity was highest in the peroxisomal fraction, whether acetyl-CoA or oxalacetate were the variable substrates. These differences indicate that peroxisomal and mitochondrial citrate synthases seem to be two different isoenzymes.
Rev Esp Fisiol 1982 Sep
PMID:Properties of peroxisomal and mitochondrial citrate synthase from Agave americana. 715 52

Male rats were either sham-operated (N) or castrated (C) at 65 days of age. They were further subdivided into sedentary or exercise groups that were trained by treadmill running 5 days/wk for 12 wk. During the last 10 days of training, the animals received daily subcutaneous injections of cortisone acetate (CA) (100 mg/kg) or 1% carboxymethylcellulose. Body weight decreased approximately 25% in all groups that received CA. The fast-twitch plantaris and gastrocnemius muscle weights were approximately 35% lower in CA-treated versus cortisone-free N and C sedentary animals. Exercise prevented from one-fourth to one-half of the muscle weight loss in N and C runners when compared to their respective pair weight controls. Muscle weights of the CA-treated freely eating N controls were significantly less than that of N runners that received CA. In plantaris muscles of both N and C animals that received CA, total protein concentration and citrate synthase activity, a mitochondrial marker, remained constant, but their amounts per muscle decreased in proportion to the atrophy. However, myoglobin concentration increased in plantaris muscles of CA-treated animals, although total myoglobin per muscle was reduced slightly. Myoglobin levels were increased in plantaris muscles both as a result of training and CA, but citrate synthase activity was increased only as a result of the exercise. These results show that exercise can retard the glucocorticoid-induced muscle atrophy.
Am J Physiol 1981 Sep
PMID:Partial prevention of glucocorticoid-induced muscle atrophy by endurance training. 728 23

The effect of a chronic (3 months) treatment with vincamine on the enzymatic activities related to energy transduction was studied on several areas of the cerebral cortex of dog brain. About enzymatic activities of the four different cortical areas, in controls, no difference was observed between the enzymatic activities evaluated in the crude mitochondrial fraction, with regard to both the tricarboxylic acid cycle (citrate synthase, malate dehydrogenase) and the electron transport chain (total NADH-cytochrome c reductase, cytochrome oxidase). On the contrary, in the homogenate, lactate dehydrogenase, malate dehydrogenase and acetylcholine esterase showed different maximal activities. In the crude mitochondrial fraction the intravenous treatment with the three different doses of vincamine failed to cause any significant change as compared to controls. On the contrary, with regard to the enzymatic activities evaluated in the homogenate in toto, the analysis of variance revealed an effect on cytochrome oxidase at the dose of 3 mg/kg intravenously.
Farmaco Sci 1981 Sep
PMID:Effect of vincamine on some enzymatic activities from various areas of the beagle dog cerebral cortex. 729 73

The changes induced by alphaxalone-alphadolone (3:1) in the cerebral enzymatic activities of the Kreb's cycle (citrate synthase, malate dehydrogenase) and electron transfer chain (total NADH-cytochrome c reductase and cytochrome oxidase) were studied. In addition, the activation of lactate dehydrogenase (for the glycolytic pathway) and of acetylcholine esterase (as indicative of transmission) were investigated. These enzymatic activities were evaluated in the homogenate in toto and/or in the crude mitochondrial fraction of rat brain, since these enzymes are variously located in the cytoplasm. Two relationships were studied: a) dose/action (0.5, 1. 2, 4, 8, 16 and 32 mg . kg-1) by measurements carried out 60 min after i.p. administration; b) time/action (16 mg . kg-1 i.p.; measurements 15, 30, 60, 120 and 240 min after administration). The results show that in both kinds of trials alphaxalone-adphadolone reduced only the activity of the enzyme cytochrome oxidase evaluated on the brain homogenate in toto. More specifically, with regard to the dose/action relationship, the effect occurred starting with the dose of 2 mg . kg-1 and did not take place linearly with the higher ones. As to the time/action relationship, the effect began 60 min after administration, the changes being observed also at the subsequent times. The data obtained are discussed with regard to the interactions between alphaxalone -alphadolone and mitochondrial enzymatic systems, and compared with the effects of phenobarbital on the same systems.
Farmaco Sci 1980 Sep
PMID:Effect of alphaxalone-alphadolone on some enzymatic activities from rat brain. 745 57

The transcripts of the citrate synthase-encoding gene (gltA) in Rickettsia prowazekii (Rp), an obligate intracellular parasitic bacterium, were analyzed by RNase protection (RP), primer extension (PE) and in vitro transcription assays. Analysis of the 5' end of the gltA mRNA by RP and PE assays revealed that there were two gltA mRNAs with the 5' ends located at 16 bp and 307 bp upstream from the gltA coding region. Since these two mRNAs might represent two species of mRNA transcribed from two different promoters or a single transcript that was processed to give two mRNAs, an in vitro transcription analysis with purified Rp RNA polymerase (RNAP) was performed to distinguish these two possibilities. Purified Rp RNAP catalyzed the formation of two transcripts initiated from the same nucleotides indicated by RP and PE. Sequence analysis identified Escherichia coli (Ec) promoter-like sequences immediately upstream from both transcription start points (tsp). The first promoter (promoter P1) had the core sequence TTCTAA-N17-TATACT, was 6 bp upstream from the tsp (base A) and was centered at 37 bp upstream from the coding region. The second promoter (promoter P2) had the core sequence ATGAAA-N17-TAAAGT, was 7 bp upstream from the tsp (base T) and was centered at 329 bp upstream from the coding region. This is the first demonstration of multiple promoters in this obligate intracellular parasite which has implications concerning transcriptional regulation.
Gene 1995 Sep 22
PMID:The citrate synthase-encoding gene of Rickettsia prowazekii is controlled by two promoters. 755 59

RNAs of Rickettsia prowazekii, an obligate intracytoplasmic bacterium, have been identified and analyzed by an RNase protection assay. Total RNA, a mixture of host cell RNA and rickettsial RNA, was isolated from rickettsia-infected mouse L929 cells by the hot-phenol method. After hybridization with specific antisense RNA probes and digestion with RNase, the protected products were analyzed by electrophoresis and autoradiography. The results show that there is only one mRNA species for the ATP/ADP translocase gene (tlc) but two mRNA species for the citrate synthase gene (gltA). RNA half-lives were determined by measuring the RNA remaining after addition of rifampin. The half-lives of tlc mRNA, gltA mRNA I, and gltA mRNA II in R. prowazekii are 8.4 +/- 0.6, 12.3 +/- 1.3, and 20.5 +/- 1.8 min, respectively. However, the half-lives of tlc mRNA and gltA mRNA I in recombinant Escherichia coli strains are 2.9 +/- 0.1 and 1.4 +/- 0.1 min, respectively. The 16S rRNA in R. prowazekii was also examined and shown to be stable.
J Bacteriol 1993 Sep
PMID:Identification of tlc and gltA mRNAs and determination of in situ RNA half-life in Rickettsia prowazekii. 769 26

The effects of regular exercise training on the onset and/or severity of hyperglycemia were studied in female diabetes-prone Biobreeding/Worcester (DP BB/Wor) rats. At 38-39 d of age, animals were weight-matched and randomly assigned to exercise-trained (T) and untrained (Unt) groups. The T rats exercised on a rodent treadmill at a moderate workload, 5 successive days with the 6th day being one of rest. Training lasted 5-11 wk until rats became moribund. Red gastrocnemius muscle citrate synthase activity was significantly higher in T (54.2 +/- 4.7 mumol.g-1.min-1) compared with Unt (42.9 +/- 5.1). No significant difference was found between the T and Unt groups in the following: age at onset of hyperglycemia (T = 82.9 +/- 8.7 d; Unt = 82.0 +/- 13.5 d, mean +/- SD), ultimate level of hyperglycemia, age of death (T = 89.9 +/- 9.2 d; Unt = 89.4 +/- 13.9 d), number of days between onset of hyperglycemia and death, or body weights at the onset of hyperglycemia. No significant difference was found between groups in pancreatic insulin concentration (microgram.g-1 of protein), T = 0.22 +/- 0.04; Unt = 0.20 +/- 0.34. These data suggest that a program of regular exercise training may not delay the onset and/or reduce the severity of hyperglycemia in the DP BB/Wor rat. Regular exercise training had no beneficial or detrimental effect on pancreatic beta-cell destruction.
Med Sci Sports Exerc 1994 Sep
PMID:Effect of exercise training on the onset of type I diabetes in the BB/Wor rat. 780 47

In some rodent skeletal muscles, hindlimb non-weight-bearing activity induces a shift in the expression of myosin heavy chains (MHCs) that favors the type II isoforms at the expense of type I. Chemically induced chronic creatine depletion results in isomyosin shifts favoring expression of type I MHCs. In this study, creatine depletion was induced separately and in combination with non-weight-bearing activity to determine if the response to lowering this metabolite would counter the MHC transitions expected from non-weight bearing. Creatine depletion was induced by feeding rats a diet supplemented with the creatine analogue beta-guanidinopropionic acid (beta-GPA). Female Sprague-Dawley rats weighing 247 +/- 8 g were randomly assigned to four groups: 1) normal diet control, 2) beta-GPA control (BC), 3) normal diet suspended (NS), and 4) beta-GPA suspended (BS). BC and BS animals were fed a diet containing the creatine analogue for 68 days. Hindlimb non-weight bearing in BS and NS animals was accomplished by tail suspension for the final 30 days of this period. beta-GPA feeding lowered the creatine content of muscles sampled by 65%. Creatine depletion resulted in a 16% increase in citrate synthase activity in the soleus (SOL) and a 24% increase in the plantaris (PLN). In two postural muscles, the SOL and vastus intermedius (VI), tail suspension resulted in large decreases in the type I MHC expression and increases in type IIx and IIb MHCs. In two locomotor muscles, the PLN and medial gastrocnemius, type I MHC declined and type IIb increased with suspension.(ABSTRACT TRUNCATED AT 250 WORDS)
J Appl Physiol (1985) 1994 Sep
PMID:Interaction of chronic creatine depletion and muscle unloading: effects on postural locomotor muscles. 783 22


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