• Title/Summary/Keyword: Tricarboxylic Acid Cycle

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The utilization of acetate for the growth and the respiration in Dunaliella tertiolecta.―Enzymes of the tricarboxylic acid cycle and glyoxylate pathway (Dunaliella tertiolecta에 의한 acetate의 이용 -TCA cycle과 glyoxylate pathway의 활성 조사-)

  • 권영명
    • Journal of Plant Biology
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    • v.16 no.1_2
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    • pp.6-11
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    • 1973
  • The utilization of acetate by Dunaliella tertiolecta was examined, and the detections and assays of the enzymes of the tricarboxylic acid cycle and the glyoxylate pathway were described. Acetate could not be utilized as a sole carbon source for the growth. The carboxyl carbon of acetate was incorporated more rapidly into CO2 than the methyl carbon. It was identified that malate, succinate, citrate and etc., were accumulated whne [U-14C] acetate was supplied to the cell free homogenate. The following enzyme activities were measured; acetothiokinase, isocitrate dehydrogenase, fumarase, malate dehydrogenase and aconitase. Though isocitratase, malate synthetase, succinate dehydrogenase and oxoglutarate dehydrogenase could not be detected, 14C from succinate was easily contributed to CO2 and cell component. The evidence suggested that the glyoxylate pathway was not operative and showed that the TCA cycle was the all important pathway in the oxidation of acetate to CO2 in Dunaliella.

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Taurine Regulates Mitochondrial Function During 7,12-Dimethyl Benz[a]anthracene Induced Experimental Mammary Carcinogenesis

  • Vanitha, Manickam Kalappan;Priya, Kalpana Deepa;Baskaran, Kuppusamy;Periyasamy, Kuppusamy;Saravanan, Dhravidamani;Venkateswari, Ramachandran;Mani, Balasundaram Revathi;Ilakkia, Aruldass;Selvaraj, Sundaramoorthy;Menaka, Rajendran;Geetha, Mahendran;Rashanthy, Nadarajah;Anandakumar, Pandi;Sakthisekaran, Dhanapal
    • Journal of Pharmacopuncture
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    • v.18 no.3
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    • pp.68-74
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    • 2015
  • Objectives: The present study was undertaken to determine the modulatory effect of taurine on the liver mitochondrial enzyme system with reference to mitochondrial lipid peroxidation (LPO), antioxidants, major tricarboxylic acid cycle enzymes, and electron transport chain enzymes during 7,12-dimethyl benz[a]anthracene (DMBA) induced breast cancer in Sprague-Dawley rats. Methods: Animals in which breast cancer had been induced by using DMBA (25 mg/kg body weight) showed an increase in mitochondrial LPO together with decreases in enzymic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST)), non-enzymic antioxidants (reduced glutathione (GSH), vitamin C, and vitamin E), in citric acid cycle enzymes (isocitrate dehydrogenase (ICDH), alpha ketoglutarate dehydrogenase (alpha KDH), succinate dehydrogenase (SDH) and malate dehydrogenase (MDH)), and in electron transport chain (ETC) complexes. Results: Taurine (100 mg/kg body weight) treatment decreased liver mitochondrial LPO and augmented the activities/levels of enzymic, and non-enzymic antioxidants, tricarboxylic acid cycle enzymes and ETC complexes. Conclusion: The results of our present study demonstrated the chemotherapeutic efficacy of taurine treatment for DMBA-induced breast carcinomas.

Inference of Aspergillus fumigatus Pathways by Computational Genome Analysis: Tricarboxylic Acid Cycle (TCA) and Glyoxylate Shunt

  • Do, Jin-Hwan;Anderson, Michael-J.;Denning, David-W.;Erich, Bornberg-Bauer
    • Journal of Microbiology and Biotechnology
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    • v.14 no.1
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    • pp.74-80
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    • 2004
  • Aspergillus fumigatus is one of the most common fungi in the human environment, both in-doors and out-doors. It is the main causative agent of invasive aspergillosis, a life-threatening mycosis among immunocompromised patients. The genome has been sequenced by an international consortium, including the Wellcome Trust Sanger Institute (U.K.) and The Institute for Genomic Research (TIGR, U.S.A.), and a ten times whole genome shotgun sequence assembly has been made publicly available. In this study, we identified tricarboxylic acid (TCA) cycle enzymes of A. fumigatus by comparative analysis with four other fungal species. The open reading frames showed high amino acid sequence similarity with the other fungal citric acid enzymes and well-conserved functional domains. All genes present in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida albicans, and Neurospora crassa were also found in A. fumigatus. In addition, we identified four A. fumigatus genes coding for enzymes in the glyoxylate shunt, which may be required for fungal virulence. The architecture of multi-gene encoded enzymes, such as isocitrate dehydrogenase, 2-ketoglutarate, succinyl-CoA synthetase, and succinate dehydrogenase was well conserved in A. fumigatus. Furthermore, our results show that genes of A. fumigatus can be detected reliably using GlimmerM.

A Study on Superoxide Dismutase from various Tissue of the Tricarboxylic acid cycle blocked Rat (Tricarboxylic acid회로를 차단한 흰쥐의 조직에서 Superoxide Dismutase에 관한 연구)

  • Kim, Yil
    • Korean Journal of Microbiology
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    • v.23 no.1
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    • pp.69-76
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    • 1985
  • This study was carried out to observe the formation of superoxide radicals and the changes in the activities of superoxide dismutase (EC.1.15.1.1.) from the various organs of a rat which was blocked tricarboxylic acid cycle. In order to block the tricarboxylic acid cycle, the beta-fluoroethylacetate was injected into peritoneal cavity of rat and removed the various tissues from the rat at internals of an hour. By tissue extracts being prepared by the method of Weigiger and Fridovich the activities of superoxide dismutase, aconitase, and contents of bliid glucose, citrates, and wuperoxide radicals were determined. The experimental results are summarized as follows: Accumulation of citrates if increased within three hours after treatment in the all tested tissues, especially, in the geart and spleen they are higher than one of other tissues as 12 and 20 times of control. The activities of aconitase are ingibited to 30-35% on an hour after beta-fluoroethylacetate treatment comparing with that of control rat. The content of blood glucose is increased to 1.6 fold of normal value after 5 hours of treatment. In all tested tissues, superoxide radicals are formed in the heart as 0.26 micromoles per gram tissue between one and three hours after treatment. The activities of total superoxide dismutase are increased between one and three hours after treatment in the all tested tissues and one of these enzymes in heart is highest. The activities of superoxide dismutase containing Mn are also increased with an increase of total superoxide dismutase activities.

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Molecular biological approaches to study the function and regulation of citrate synthase genes in saccharomyces cerevisiae

  • Kim, Kwang-Soo;Rosankranz, Mark;Guarente, Leonard
    • The Microorganisms and Industry
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    • v.12 no.2
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    • pp.30-35
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    • 1986
  • Almost all of the aerobic organisms contain citric acid cycle (or, tricarboxylic acid cycle). This cycle is involved both in energy metabolism and biosynthetic reactions; generation of NADH which derives the synthesis of chemical energy, ATP, and provision of intermediates needed for the biosynthesis. Because of its importance in the cellular metabolism, the regulation of the TCA cycle and its component enzymes has been extensively studied by many biologists (7,28). Citrate synthase is resposible for the initial step of the cycle and has been recognized as the rate limiting step (14,121,26). Understanding of the mechanism of the expression of citrate synthase should be a key step for the elucidation of the regulation of the TCA cycle in the cell metabolism.

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Dexamethasone enhances glucose uptake by SGLT1 and GLUT1 and boosts ATP generation through the PPP-TCA cycle in bovine neutrophils

  • Wang, Xinbo;Tang, Mingyu;Zhang, Yuming;Li, Yansong;Mao, Jingdong;Deng, Qinghua;Li, Shusen;Jia, Zhenwei;Du, Liyin
    • Journal of Veterinary Science
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    • v.23 no.5
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    • pp.76.1-76.14
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    • 2022
  • Background: Clinical dexamethasone (DEX) treatment or stress in bovines results in extensive physiological changes with prominent hyperglycemia and neutrophils dysfunction. Objectives: To elucidate the effects of DEX treatment in vivo on cellular energy status and the underlying mechanism in circulating neutrophils. Methods: We selected eight-month-old male bovines and injected DEX for 3 consecutive days (1 time/d). The levels of glucose, total protein (TP), total cholesterol (TC), and the proinflammatory cytokines interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in blood were examined, and we then detected glycogen and adenosine triphosphate (ATP) content, phosphofructosekinase-1 (PFK1) and glucose-6-phosphate dehydrogenase (G6PDH) activity, glucose transporter (GLUT)1, GLUT4, sodium/glucose cotransporter (SGLT)1 and citrate synthase (CS) protein expression and autophagy levels in circulating neutrophils. Results: DEX injection markedly increased blood glucose, TP and TC levels, the Ca2+/P5+ ratio and the neutrophil/lymphocyte ratio and significantly decreased blood IL-1β, IL-6 and TNF-α levels. Particularly in neutrophils, DEX injection inhibited p65-NFκB activation and elevated glycogen and ATP contents and SGLT1, GLUT1 and GR expression while inhibiting PFK1 activity, enhancing G6PDH activity and CS expression and lowering cell autophagy levels. Conclusions: DEX induced neutrophils glucose uptake by enhancing SGLT1 and GLUT1 expression and the transformation of energy metabolism from glycolysis to pentose phosphate pathway (PPP)-tricarboxylic acid (TCA) cycle. This finding gives us a new perspective on deeper understanding of clinical anti-inflammatory effects of DEX on bovine.

Some Enzymes of Tricarboxylic Acid Cycle and Metabolites of Carbohydrate Metabolism in Adult Isoparorchis hypselobagri(Digenea: Trematoda) During in vitro Starvation

  • Bera, Bireshwar;Manna, Buddhadeb
    • International Journal of Industrial Entomology and Biomaterials
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    • v.18 no.2
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    • pp.91-95
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    • 2009
  • The presence of considerable amount of enzymes of TCA cycle isocitrate dehydrogenase (ICDH-NADP+, EC1.1.1.42), $\alpha$-ketogluterate dehydrogenase ($\alpha$-KGD, EC1.2.4.2) and malate dehydrogenase (MDH, EC1.1.1.37) in fresh control and in vitro starved adult Isoparorchis hypselobagri establish the functional TCA cycle in this fluke. The major metabolic end products are pyruvate, lactate, oxaloacetate and malate. The ratio of oxaloacetate/malate assess that oxaloacetate is reduced to malate and in this fluke the reverse TCA cycle is active. The pyruvate/lactate ratio shows pyruvate is reduced to lactate and the fluke is homolactate farmenters.

Fatty acid uptake and oxidation in skeletal muscle

  • Yun, Hea-Yeon;Tamura, Tomohiro;Lim, Kiwon
    • Korean Journal of Exercise Nutrition
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    • v.16 no.1
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    • pp.1-9
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    • 2012
  • Long chain fatty acids (LCFAs) are transported into cells via plasma transporters, are activated to fatty acyl-CoA by fatty acyl-CoA synthase (ACS), and enter mitochondria via the carnitine system (CPT1/CACT/CPT2). The mitochondrial carnitine system plays an obligatory role in β-oxidation of LCFAs by catalyzing their transport into the mitochondrial matrix. Fatty acyl-CoAs are oxidized via the β-oxidation pathway, which results in the production of acetyl-CoA. The acetyl-CoA can be imported into the tricarboxylic acid (TCA) cycle for oxidation in the mitochondrial matrix or can be used for malonyl-CoA synthesis by acetyl-CoA carboxylase 2 (ACC2) in the cytoplasm. In skeletal muscle, ACC2 catalyzes the carboxylation of acetyl-CoA to form malonyl-CoA, which is a potent endogenous inhibitor of carnitine palmitoyltransferase 1 (CPT1). Thus, ACC2 indirectly inhibits the influx of fatty acids into the mitochondria. Fatty acid metabolism can also be regulated by malonyl-CoA-mediated inhibition of CPT1.

From the Photosynthesis to Hormone Biosynthesis in Plants

  • Hyong Woo Choi
    • The Plant Pathology Journal
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    • v.40 no.2
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    • pp.99-105
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    • 2024
  • Land plants produce glucose (C6H12O2) through photosynthesis by utilizing carbon dioxide (CO2), water (H2O), and light energy. Glucose can be stored in various polysaccharide forms for later use (e.g., sucrose in fruit, amylose in plastids), used to create cellulose, the primary structural component of cell walls, and immediately metabolized to generate cellular energy, adenosine triphosphate, through a series of respiratory pathways including glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation. Additionally, plants must metabolize glucose into amino acids, nucleotides, and various plant hormones, which are crucial for regulating many aspects of plant physiology. This review will summarize the biosynthesis of different plant hormones, such as auxin, salicylic acid, gibberellins, cytokinins, ethylene, and abscisic acid, in relation to glucose metabolism.