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.

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.

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 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.

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.

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.

scholarly journals Anaerobic Induction of Isocitrate Lyase and Malate Synthase in Submerged Rice Seedlings Indicates the Important Metabolic Role of the Glyoxylate Cycle

2005 ◽  
Vol 37 (6) ◽  
pp. 406-414 ◽  
Author(s):  
Ying Lu ◽  
Yong-Rui Wu ◽  
Bin Han
Keyword(s):  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Fold Increase ◽  
Malate Synthase ◽  
Acetate Metabolism ◽  
Activity Assay ◽  
Rice Seedlings ◽  
Metabolic Role ◽  
The Glyoxylate Cycle

Abstract The glyoxylate cycle is a modified form of the tricarboxylic acid cycle that converts C2 compounds into C4 dicarboxylic acids at plant developmental stages. By studying submerged rice seedlings, we revealed the activation of the glyoxylate cycle by identifying the increased transcripts of mRNAs of the genes of isocitrate lyase (ICL) and malate synthase (MS), two characteristic enzymes of the glyoxylate cycle. Northern blot analysis showed that ICL and MS were activated in the prolonged anaerobic environment. The activity assay of pyruvate decarboxylase and ICL in the submerged seedlings indicated an 8.8-fold and 3.5-fold increase over that in the unsubmerged seedlings, respectively. The activity assay of acetyl-coenzyme A synthetase in the submerged seedlings indicated a 3-fold increase over that in the unsubmerged seedlings, which is important for initiating acetate metabolism. Consequently, we concluded that the glyoxylate cycle was involved in acetate metabolism under anaerobic conditions.

The role of isocitrate lyase in the metabolism of algae

1966 ◽  
Vol 166 (1002) ◽  
pp. 11-29 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Soluble Fraction ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Tricarboxylic Acid ◽  
Chlamydomonas Reinhardii ◽  
The Glyoxylate Cycle ◽  
Do So

The incorporation of isotope from [2- 14 C]ethanol by cultures of the Brannon no. 1 strain of Chlorella vulgaris , growing on ethanol aerobically in the dark, was consistent with the operation of the tricarboxylic acid and glyoxylate cycles. Results obtained with [l- 14 C]acetate, added to similar cultures growing on glucose in the dark or on carbon dioxide in the light, indicated that the glyoxylate cycle did not function under these conditions. However, one of the key enzymes of this cycle, isocitrate lyase, was present in large amounts in extracts of this organism under all conditions of growth; in contrast, isocitrate lyase was inducibly formed by Chlamydomonas reinhardii prior to growth on acetate. No obvious dysfunction of the tricarboxylic acid cycle, which might necessitate the activity of isocitrate lyase during growth on other than C 2 -compounds, was detected in the Brannon no. 1 strain, nor were differences observed between the properties of the enzyme purified from cells grown on acetate and on glucose. But, whereas isocitrate lyase was wholly found in a soluble fraction of the organism after growth on glucose or on carbon dioxide, acetate-grown cells contained a major portion of their isocitrate lyase in a dense, particulate fraction. The Brannon no. 1 strain of Chlorella excreted labelled glycollate during growth in the dark on glucose in the presence of sodium [ 14 C]bicarbonate, but ceased to do so after transfer to acetate growth medium. The Pearsall’s strain of Chlorella , which does not form isocitrate lyase during growth on glucose, did not excrete labelled glycollate under these conditions. These results suggest that the Brannon no. 1 strain of Chlorella contained an active isocitrate lyase under all conditions of growth, but that this enzyme participates in the glyoxylate cycle only when it is incorporated into a particulate structure.

Co-ordinate regulation of genes involved in storage lipid mobilization in Arabidopsis thaliana

2001 ◽  
Vol 29 (2) ◽  
pp. 283-286 ◽  
Author(s):  
E. L. Rylott ◽  
M. A. Hooks ◽  
I. A. Graham
Keyword(s):  
Arabidopsis Thaliana ◽  
Enzyme Activities ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Molecular Genetic ◽  
Regulation Of Gene Expression ◽  
Growth Period ◽  
Malate Synthase ◽  
The Glyoxylate Cycle

Molecular genetic approaches in the model plant Arabidopsis thaliana (ColO) are shedding new light on the role and control of the pathways associated with the mobilization of lipid reserves during oilseed germination and post-germinative growth. Numerous independent studies have reported on the expression of individual genes encoding enzymes from the three major pathways: β-oxidation, the glyoxylate cycle and gluconeogenesis. However, a single comprehensive study of representative genes and enzymes from the different pathways in a single plant species has not been done. Here we present results from Arabidopsis that demonstrate the co-ordinate regulation of gene expression and enzyme activities for the acyl-CoA oxidase- and 3-ketoacyl-CoA thiolasemediated steps of β-oxidation, the isocitrate lyase and malate synthase steps of the glyoxylate cycle and the phosphoenolpyruvate carboxykinase step of gluconeogenesis. The mRNA abundance and enzyme activities increase to a peak at stage 2, 48 h after the onset of seed germination, and decline thereafter either to undetectable levels (for malate synthase and isocitrate lyase) or low basal levels (for the genes of β-oxidation and gluconeogenesis). The co-ordinate induction of all these genes at the onset of germination raises the possibility that a global regulatory mechanism operates to induce the expression of genes associated with the mobilization of storage reserves during the heterotrophic growth period.

scholarly journals Physiological Ecology of Stenoxybacter acetivorans, an Obligate Microaerophile in Termite Guts

2007 ◽  
Vol 73 (21) ◽  
pp. 6829-6841 ◽  
Author(s):  
John T. Wertz ◽  
John A. Breznak
Keyword(s):  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Reticulitermes Flavipes ◽  
Peripheral Region ◽  
Malate Synthase ◽  
Rrna Gene ◽  
Potential Contribution ◽  
Cell Extracts

ABSTRACT Stenoxybacter acetivorans is a newly described, obligately microaerophilic β-proteobacterium that is abundant in the acetate-rich hindgut of Reticulitermes. Here we tested the hypotheses that cells are located in the hypoxic, peripheral region of Reticulitermes flavipes hindguts and use acetate to fuel their O2-consuming respiratory activity in situ. Physical fractionation of R. flavipes guts, followed by limited-cycle PCR with S. acetivorans-specific 16S rRNA gene primers, indicated that cells of this organism were indeed located primarily among the microbiota colonizing the hindgut wall. Likewise, reverse transcriptase PCR of hindgut RNA revealed S. acetivorans-specific transcripts for acetate-activating enzymes that were also found in cell extracts (acetate kinase and phosphotransacetylase), as well as transcripts of ccoN, which encodes the O2-reducing subunit of high-affinity cbb 3-type cytochrome oxidases. However, S. acetivorans strains did not possess typical enzymes of the glyoxylate cycle (isocitrate lyase and malate synthase A), suggesting that they may use an alternate pathway to replenish tricarboxylic acid cycle intermediates or they obtain such compounds (or their precursors) in situ. Respirometric measurements indicated that much of the O2 consumption by R. flavipes worker larvae was attributable to their guts, and the potential contribution of S. acetivorans to O2 consumption by extracted guts was about 0.2%, a value similar to that obtained for other hindgut bacteria examined. Similar measurements obtained with guts of larvae prefed diets to disrupt major members of the hindgut microbiota implied that most of the O2 consumption observed with extracted guts was attributable to protozoans, a group of microbes long thought to be “strict anaerobes.”

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