THE TRICARBOXYLIC ACID CYCLE, THE GLYOXYLATE CYCLE, AND THE ENZYMES OF GLUCOSE OXIDATION IN PSEUDOMONAS AERUGINOSA

1966 ◽  
Vol 12 (5) ◽  
pp. 1015-1022 ◽  
Author(s):  
Margaret von Tigerstrom ◽  
J. J. R. Campbell
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Glucose Oxidation ◽  
Nadh Oxidase ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
The Glyoxylate Cycle

The enzymes of the glyoxylate cycle, the tricarboxylic acid cycle, glucose oxidation, and hydrogen transport were measured in extracts of Pseudomonas aeruginosa grown with glucose, α-ketoglutarate, or acetate as sole carbon source. The specific activity of isocitritase was increased 25-fold by growth on acetate whereas malate synthetase was increased only 4-fold. All of the enzymes of glucose metabolism, operative at the hexose level, were inducible. The enzymes of the tricarboxylic acid cycle were present under all conditions of growth but extracts from acetate-grown cells contained only one-quarter of the fumarase and pyruvic oxidase activity and half the malate-oxidizing activity of the other extracts. Transhydrogenase, NADH oxidase, and NADPH oxidase activities were similar in each type of extracts. Most of the enzymes were present in the soluble cytoplasm, exceptions being glucose oxidase, succinic dehydrogenase, and NADH oxidase.

THE TRICARBOXYLIC ACID AND GLYOXYLATE CYCLES IN XANTHOMONAS PHASEOLI (XP8)

1959 ◽  
Vol 5 (1) ◽  
pp. 1-8 ◽  
Author(s):  
N. B. Madsen ◽  
R. M. Hochster
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Sole Source ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Main Pathway ◽  
The Individual ◽  
Acetate Medium ◽  
Terminal Oxidation ◽  
The Glyoxylate Cycle

Cell-free extracts of Xanthomonas phaseoli contain the individual enzymes of the tricarboxylic acid cycle, and it is suggested that this is the main pathway for the terminal oxidation of carbohydrate in this organism. X. phaseoli can grow on a medium containing acetate as the sole source of carbon. Cell-free extracts of such acetate-grown organisms contain the enzymes of the glyoxylate cycle, and it is concluded that the operation of this cycle permits the initial stages of synthesis of complex cell material from acetate at a rate sufficiently high to account for the observed rate of growth on the acetate medium. The two enzymes required to modify a tricarboxylic acid cycle into a glyoxylate cycle are present in very small amounts (malate synthetase) or absent entirely (isocitritase) in extracts of glucose-grown X. phaseoli.

scholarly journals The localization of enzymes of intermediary metabolism in Astasia and Euglena

1973 ◽  
Vol 134 (2) ◽  
pp. 607-616 ◽  
Author(s):  
Nicole Bégin-Heick
Keyword(s):  
Succinate Dehydrogenase ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Intracellular Localization ◽  
Tricarboxylic Acid ◽  
Malate Synthase ◽  
Particulate Fraction ◽  
Acid Cycle ◽  
The Glyoxylate Cycle

Results are presented on the intracellular localization of some of the enzymes of gluconeogenesis, of the tricarboxylic acid cycle and of related enzymes in Astasia and Euglena grown with various substrates. The results indicate the particulate nature of at least part of the malate synthase of Astasia and of part of the malate synthase and isocitrate lyase in Euglena. However, the presence of glyoxysomes (microbodies) in Astasia and Euglena is still open to question, since it has not, so far, been possible to separate the enzymes of the glyoxylate cycle from succinate dehydrogenase in the particulate fraction.

A MATHEMATICAL ANALYSIS OF THE COMBINED TRICARBOXYLIC ACID - GLYOXYLATE CYCLES

1967 ◽  
Vol 45 (6) ◽  
pp. 863-872
Author(s):  
R. M. R. Branion ◽  
B. F. J. Caddick ◽  
W. B. McConnell
Keyword(s):  
Experimental Data ◽  
Mathematical Analysis ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Combined Operation ◽  
Simplifying Assumptions ◽  
The Individual ◽  
The Glyoxylate Cycle

The problem of interpreting data on the distribution of isotopic carbon in intermediates of the tricarboxylic acid cycle and the glyoxylate cycle is discussed. An effort is made to examine mathematically the effects of cycling on the distribution of isotope in the carbon skeletons of intermediates of these cycles. Consideration is given to the individual cycles and to combinations of the two. Because the systems are highly complex, a number of simplifying assumptions are made which limit the usefulness of the equations derived for dealing with experimental data. However, some significant features of labelling that result from combined operation of the two cycles are emphasized, which should make it possible to estimate their relative contributions more reliably than by qualitative inspection of the data.

Changes in activity of certain enzymes of the tricarboxylic acid cycle and the glyoxylate cycle during the initiation of conidiation of Aspergillus niger

1969 ◽  
Vol 15 (10) ◽  
pp. 1207-1212 ◽  
Author(s):  
J. C. Galbraith ◽  
J. E. Smith
Keyword(s):  
Life Cycle ◽  
Aspergillus Niger ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Glycine Synthesis ◽  
The Glyoxylate Cycle

The activities of certain enzymes of the tricarboxylic acid (TCA) cycle and the glyoxylate cycle (GLC) varied during growth of Aspergillus niger as a function of the stage of the life cycle and of the growth medium. Isocitrate dehydrogenase (carboxylating) and isocitrate lyase each showed a marked increase in activity prior to sporulation. There were no similar increases in vegetative cultures. It is proposed that isocitrate lyase is functional in glycine synthesis and that a source of glyoxylate may be indispensable to the expression of sporulation.

scholarly journals TRICARBOXYLIC ACID CYCLE IN PSEUDOMONAS AERUGINOSA

1951 ◽  
Vol 190 (2) ◽  
pp. 853-858
Author(s):  
Jack J.R. Campbell ◽  
Flora.Norris. Stokes
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle

THE ENZYMES OF THE TRICARBOXYLIC ACID CYCLE OF PSEUDOMONAS AERUGINOSA

1956 ◽  
Vol 2 (4) ◽  
pp. 433-440 ◽  
Author(s):  
Jack J. R. Campbell ◽  
Roberts A. Smith
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Malic Acid ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
The Other ◽  
Acid Cycle ◽  
High Ph ◽  
Optimum Activity ◽  
Fresh Cell ◽  
Cell Extracts

It was demonstrated that Pseudomonas aeruginosa possesses all the enzymes necessary for the oxidation of pyruvate to CO2 and water without passing through the conventional intermediates oxalosuccinate and α-ketoglutarate. These intermediates are bypassed by the action of the enzyme isocitratase which splits d-isocitrate to succinate plus glyoxylate. This reaction was shown to be readily reversible. The malic acid dehydrogenase content was low and in addition this enzyme required a high pH for optimum activity. In fresh cell extracts at pH 7.4 its activity was only 10% that of the other enzymes of the cycle. The malic and isocitric dehydrogenases were TPN specific. The organism was also shown to possess all the enzymes necessary for the operation of the conventional tricarboxylic acid cycle.

scholarly journals Up-regulation of glucose metabolism in Kupffer cells following infusion of tumour necrosis factor

1991 ◽  
Vol 278 (2) ◽  
pp. 515-519 ◽  
Author(s):  
Z Spolarics ◽  
G J Bagby ◽  
C H Lang ◽  
J J Spitzer
Keyword(s):  
Endothelial Cells ◽  
Kupffer Cells ◽  
Tumour Necrosis ◽  
Glucose Oxidation ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Necrosis Factor

Alterations of glucose metabolism and the oxidation of glutamine and palmitate were studied, by using specifically labelled substrates, in freshly isolated Kupffer cells and hepatic endothelial cells after infusion in vivo of human recombinant tumour necrosis factor-alpha (TNF; 7.5 x 10(5) IU/30 min per kg body wt., intravenously). Cells were incubated in a medium containing 5 mM-glucose, 0.4 mM-palmitate, 1 mM-lactate and 0.5 mM-glutamine. Administration of TNF in vivo increased glucose use in Kupffer cells by 70%. Glucose oxidation in the tricarboxylic acid cycle and flux in the Embden-Meyerhof (EM) pathway were elevated by 40 and 80% respectively. Treatment in vitro with 1 microM-phorbol 12-myristate 13-acetate (PMA) resulted in a similar percentage increase in glucose use by Kupffer cells prepared from either saline- or TNF-treated rats. However, PMA increased the activity of the hexose monophosphate shunt (HMS) by 3- and 10-fold in cells isolated from saline- or TNF-infused animals respectively. A phagocyte stimulus in vitro, opsonized zymosan, increased glucose use by 30% and doubled the flux through the HMS in Kupffer cells from saline-infused animals. The activity of the HMS in response to zymosan was increased by 400% after TNF treatment. In endothelial cells, basal glucose utilization was not altered by TNF treatment. PMA increased HMS activity in endothelial cells to a similar degree after saline or TNF infusion. Zymosan, however, increased HMS activity only in endothelial cells from TNF-treated rats. Oxidation of palmitate or glutamine was not affected by TNF treatment either under basal conditions or after challenge in vitro. Our data indicate that, after phagocytosis in vitro or protein kinase C activation, glucose use and flux through the HMS increase in Kupffer cells. This is accompanied by increased glycolytic flux, with no changes in glucose oxidation in the tricarboxylic acid cycle. After TNF exposure, followed by a secondary stimulus, the enhanced glucose use by Kupffer cells is primarily channelled through the HMS pathway. These data suggest that the increased glucose use in vivo by Kupffer cells found after immune-stimulated conditions may subserve primarily the increased need for NADPH and HMS intermediates.

scholarly journals IN VITRO EFFECTS OF FLUORIDE ON TRICARBOXYLIC ACID CYCLE DEHYDROGENASES AND OXIDATIVE PHOSPHORYLATION: PART I

1967 ◽  
Vol 15 (4) ◽  
pp. 195-201 ◽  
Author(s):  
C. JAMES LOVELACE ◽  
GENE W. MILLER
Keyword(s):  
Oxidative Phosphorylation ◽  
Competitive Inhibition ◽  
Tricarboxylic Acid Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Initial Increase ◽  
Acid Cycle ◽  
Oxidase System ◽  
Vitro Effect

Studies were conducted on the in vitro effect of fluoride on the succinic oxidase system utilizing mitochondria obtained from cauliflower. Preincubation of mitochondria with fluoride did not increase inhibition of succinic oxidase. Various other tricarboxylic acid cycle substrates were used to determine their sensitivity to fluoride; only succinate oxidation was affected. A series of succinate concentrations in the presence and in the absence of fluoride showed increased activity of succinic dehydrogenase, which indicated competitive inhibition. Various concentrations of phosphate in the absence of fluoride showed that phosphate had only slight effects on the succinic 2,6-dichlorophenolindophenol reductase component of the succinic oxidase system. In the absence of phosphate, various concentrations of fluoride showed an initial increase in activity followed by a decrease in activity of succinic 2,6-dichlorophenolindophenol reductase. In the presence of phosphate, fluoride caused marked inhibition of succinic 2,6-dichlorophenolindophenol reductase. It is believed that this inhibition results from an enzyme-fluorophosphate complex which has a lower dissociation constant than that of the enzyme-substrate complex. An oxidative phosphorylation study indicated that both respiration and phosphorylation were inhibited.

scholarly journals Correlation of dicarboxylic acid cycle with tricarboxylic acid cycle in highly productive pigs

2020 ◽  
Vol 58 (2) ◽  
pp. 215-225
Author(s):  
K. S. Ostrenko ◽  
V. P. Galochkina ◽  
V. О. Lemiasheuski ◽  
A. V. Agafonova ◽  
A. N. Ovcharova ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Lower Layer ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Krebs Cycle ◽  
Tricarboxylic Acid ◽  
Malate Synthase ◽  
The Body ◽  
Mitochondrial Enzymes ◽  
Acid Cycle

The paper is the fundamental beginning of research series aimed at understanding the processes associated with high performance in higher animals. The research aim is to study correlation of dicarboxylic acid cycle with tricarboxylic acid cycle with establishment of activity and dislocation of enzymes, confirming the hypothesis of availability and active metabolic participation of peroxisome in highly productive animals. Research was conducted on the basis of the VNIIFBiP animal vivarium in 2019 with a group of piglets of the Irish Landrace breed (n = 10). After slaughter at the age of 210 days, the nuclear (with large tissue particles), mitochondrial and postmitochondrial fractions of the liver were studied with assessment of succinate dehydrogenase and activity of other dehydrogenes of the Krebs cycle. It was found that peroxisomes act as universal agents of communication and cooperation, and microtelets are able to generate various chemical signals that carry information, to control and arrange a number of mechanisms in the metabolic processes in the body. Despite the fact that the Krebs cycle dehydrogenases are considered mitochondrial enzymes, the experiment showed an increase in activity of priruvate dehydrogenase (P > 0.1), isocitrate dehydrogenase (0.1 > P > 0.05) and malate dehydrogenase (0.1 > P > 0.05), which, when comparing the mitochondrial and postmitochondrial fractions, indicates a higher activity of peroxisomal fractions. The peroxisome localization place is the postmitochondrial fraction, and the lower layer contains larger peroxisomes to a greater extent, while the upper layer contains smaller ones. It was found that indicator enzymes of glyoxylate cycle isocitratliase and malate synthase exhibit catalytic activity in the peroxisomal fraction of liver of highly productive pigs. The obtained data on functioning of key glyoxylate cycle enzymes and their intracellular compartmentalization in highly productive pigs allow learning more about the specifics of metabolism and its regulation processes. Application of this knowledge in practice opens up prospects for rationalizing the production of livestock products of increased quantity, improved quality with less feed, labor and financial resources spent.

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