scholarly journals Oscillations of enzyme activities during the cell-cycle of a glucose-repressed fission-yeast Schizosaccharomyces pombe 972h

1973 ◽  
Vol 136 (1) ◽  
pp. 195-207 ◽  
Author(s):  
R. K. Poole ◽  
D. Lloyd
Keyword(s):  
Cell Cycle ◽  
Cytochrome C ◽  
Schizosaccharomyces Pombe ◽  
Succinate Dehydrogenase ◽  
Cytochrome C Oxidase ◽  
Malate Dehydrogenase ◽  
Enzyme Activities ◽  
Nadh Dehydrogenase ◽  
Nadph Cytochrome ◽  
Nadh Cytochrome

1. Increased specific activities of cytochrome c oxidase, catalase, succinate dehydrogenase, succinate–cytochrome c oxidoreductase, NADH–cytochrome c oxidoreductase and malate dehydrogenase were observed during glucose de-repression of Schizosaccharomyces pombe. 2. The cell-cycle of this organism was analysed by three different methods: (a) harvesting of cells at intervals from a synchronous culture, (b) separation of cells by rate-zonal centrifugation into different size classes and (c) separation of cells by isopycnic-zonal centrifugation into different density classes. 3. Measurement of enzyme activities during the cell-cycle showed that all the enzymes assayed [cytochrome c oxidase, catalase, acid p-nitrophenylphosphatase, NADH-dehydrogenase, NADH–cytochrome c oxidoreductase, NADPH–cytochrome c oxidoreductase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase (NADP) and fumarate hydratase] show periodic expression as ‘peaks’. 4. Cytochrome c oxidase shows a single maximum at 0.67 of a cycle, whereas succinate dehydrogenase exhibits two maxima separated by 0.5 of a cell-cycle. 5. All other enzymes assayed showed two distinct maxima per cell-cycle; for catalase, malate dehydrogenase and NADPH–cytochrome c oxidoreductase there is the possibility of multiple fluctuations. 6. The single maximum of cytochrome c oxidase appears at a similar time in the cycle to one maximum of each of the other enzymes studied, except for NADH dehydrogenase. 7. These results are discussed with reference to previous observations on the expression of enzyme activities during the cell-cycle of yeasts.

scholarly journals Changes in respiratory activities during the cell-cycle of the fission yeast Schizosaccharomyces pombe 972h- growing in the presence of glycerol

1974 ◽  
Vol 144 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Robert K. Poole ◽  
David Lloyd
Keyword(s):  
Cell Cycle ◽  
Cytochrome C ◽  
Schizosaccharomyces Pombe ◽  
Succinate Dehydrogenase ◽  
Cytochrome C Oxidase ◽  
Similar Time ◽  
Batch Cultures ◽  
Synchronous Cultures ◽  
Time Courses ◽  
Nadh Cytochrome

1. The specific activities of cytochrome c oxidase, catalase, succinate dehydrogenase, succinate–cytochrome c oxidoreductase, NADH–cytochrome c oxidoreductase, and NADPH–cytochrome c oxidoreductase in mid-exponential-phase batch cultures of glycerol-grown Schizosaccharomyces pombe indicated that the organisms were catabolite-de-repressed. 2. In cultures growing synchronously in the presence of glycerol as sole carbon source, the respiration rate showed two abrupt increases at about 0.45 and 0.95 of the cell-cycle and remained constant in the periods between successive rises. 3. Catalase, succinate dehydrogenase, NADH–cytochrome c oxidoreductase and acid p-nitrophenyl-phosphatase all showed peak patterns of expression in synchronous cultures. 4. Cytochrome c oxidase and cytochromes a+a3 both showed step patterns of expression with two rises per cell-cycle. 5. Cytochromes c548, b554 and b560 all followed similar time-courses in step patterns of expression, but these were distinct from, and more complex than, that of cytochromes a+a3. 6. These results are compared with those previously obtained with glucose-grown cultures, and the part played by catabolite repression in the expression of respiratory activities in the cell-cycle is assessed.

scholarly journals Effects of L-Malate on Mitochondrial Oxidoreductases in Liver of Aged Rats

2011 ◽  
pp. 329-336 ◽  
Author(s):  
J.-L. WU ◽  
Q.-P. WU ◽  
Y.-P. PENG ◽  
J.-M. ZHANG
Keyword(s):  
Electron Transport ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Electron Transport Chain ◽  
Nadh Dehydrogenase ◽  
Tricarboxylic Acid Cycle ◽  
Radical Scavenger ◽  
Aged Rats ◽  
Transport Chain ◽  
Nadh Cytochrome

Accumulation of oxidative damage has been implicated to be a major causative factor in the decline in physiological functions that occur during the aging process. The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS), considered as the pathogenic agent of many diseases and aging. L-malate, a tricarboxylic acid cycle intermediate, plays an important role in transporting NADH from cytosol to mitochondria for energy production. Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. In the present study we focused on the effect of L-malate on the activities of electron transport chain in young and aged rats. We found that mitochondrial membrane potential (MMP) and the activities of succinate dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats were significantly decreased when compared to young control rats. Supplementation of L-malate to aged rats for 30 days slightly increased MMP and improved the activities of NADH-dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats when compared with aged control rats. In young rats, L-malate administration increased only the activity of NADH-dehydrogenase. Our result suggested that L-malate could improve the activities of electron transport chain enzymes in aged rats

scholarly journals Changes in enzyme activities and distributions during glucose de-repression and respiratory adaptation of anaerobically grown Saccharomyces carlsbergensis

1973 ◽  
Vol 132 (3) ◽  
pp. 609-621 ◽  
Author(s):  
T. G. Cartledge ◽  
D. Lloyd
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Respiration Rate ◽  
Enzyme Activities ◽  
Specific Activity ◽  
Antimycin A ◽  
Saccharomyces Carlsbergensis ◽  
Whole Cells ◽  
Nadh Cytochrome ◽  
A Minor

1. During anaerobic glucose de-repression the respiration rate of whole cells of Saccharomyces carlsbergensis remained constant and was insensitive to antimycin A but was inhibited by 30% by KCN. Aeration of cells for 1 h led to increased respiration rate which was inhibited by 80% by antimycin A or KCN. 2. Homogenates were prepared from sphaeroplasts of anaerobically grown, glucose de-repressed cells and the distribution of marker enzymes was investigated after zonal centrifugation on sucrose gradients containing MgCl2. These homogenates contained no detectable cytochrome c oxidase or catalase activity. The complex density distributions of NADH– and NADPH–cytochrome c oxidoreductases and adenosine triphosphatase(s) [ATPase(s)] were very different from those of anaerobically grown, glucose-repressed cells. 3. The specific activity of total ATPase was lowered and sensitivity to oligomycin decreased from 58 to 7% during de-repression. 4. Cytochrome c oxidase and catalase activities were detectable in homogenates of cells after 10min aeration. Zonal centrifugation indicated complex, broad sedimentable distributions of all enzyme activities assayed; the peaks of activity were at 1.27g/ml. 5. Centrifugation of homogenates of cells adapted for 30min and 3 h indicated a shift of density of the major sedimentable peak from 1.25g/ml (30min) to 1.235g/ml (3 h). After 30min adaptation a minor zone of oligomycin-sensitive ATPase and 15% of the total cytochrome c oxidase activities were detected at ρ=1.12g/l; these particles together with those of higher density containing cytochrome c oxidase, ATPase and NADH–cytochrome c oxidoreductase activities were all sedimented at 105g-min. 6. Electron microscopy indicated that the mitochondria-like structures of anaerobically grown, glucose-de-repressed cells were similar to those of repressed cells. After 10min of respiratory adaptation highly organized mitochondria were evident which resembled the condensed forms of mitochondria of aerobically grown, glucose-de-repressed cells. High-density zonal fractions of homogenates of cells after adaptation also contained numerous electron-dense vesicles 0.05–0.2μm in diameter. 7. The possibility that the `promitochondria' of anaerobically grown cells may not be the direct structural precursors of fully functional mitochondria is discussed.

scholarly journals The development of cytochromes during the cell cycle of a glucose-repressed fission yeast, Schizosaccharomyces pombe 972h−

1974 ◽  
Vol 138 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Robert K. Poole ◽  
David Lloyd ◽  
Britton Chance
Keyword(s):  
Cell Cycle ◽  
Cytochrome C ◽  
Schizosaccharomyces Pombe ◽  
Cytochrome C Oxidase ◽  
Glucose Repression ◽  
Spectrophotometric Analysis ◽  
Difference Spectra ◽  
Intact Cells ◽  
The Relationship ◽  
Cytochrome P 450

1. Spectrophotometric analysis of intact cells of Schizosaccharomyces pombe, harvested from exponentially growing cultures during the phase of glucose repression, revealed the presence of cytochromes a+a3, c and at least two species of cytochrome b. 2. An absorption maximum at 554nm at 77°K, previously attributed to cytochrome c1, has been identified as a b-type cytochrome. 3. CO-difference spectra reveal the presence of cytochromes P-420 and P-450 in addition to cytochrome a3. 4. The cell cycle was analysed by separation of cells into classes representing successive stages in the cell cycle by isopycnic zonal centrifugation. 5. Cytochromes c548, b554 and b560 each exhibited a single broad maximum of synthesis during the cell cycle. 6. Amounts of cytochromes a+a3 and b563 (tentatively identified as cytochrome bT by its reaction on pulsing anaerobic cell suspensions with O2) oscillated in phase, and showed two maxima during the cycle; the second maximum of cytochromes a+a3 was coincident with a maximum of activity of enzymically active cytochrome c oxidase. 7. The amount of cytochrome P-420 decreased during the first three-quarters of the cell-cycle, whereas that of cytochrome P-450 increased during this period. 8. The discrepancy between spectrophotometric and enzymic assay of cytochrome c oxidase, the changing ratio of cytochrome a3/cytochrome a and the relationship between changes in cellular content of cytochromes and previous observations on respiratory oscillations during the cell cycle are discussed.

scholarly journals Pathology of Mitochondrial Encephalomyopathies

2005 ◽  
Vol 32 (2) ◽  
pp. 152-166 ◽  
Author(s):  
Harvey B. Sarnat ◽  
José Marín-García
Keyword(s):  
Cytochrome C ◽  
Succinate Dehydrogenase ◽  
Cytochrome C Oxidase ◽  
Oxidase Activity ◽  
Morphological Evidence ◽  
Regular Feature ◽  
Complex Iv ◽  
Genetic Studies ◽  
Mitochondrial Encephalomyopathies ◽  
Mitochondrial Cytopathy

ABSTRACT:Muscle biopsy provides the best tissue to confirm a mitochondrial cytopathy. Histochemical features often correlate with specific syndromes and facilitate the selection of biochemical and genetic studies. Ragged-red fibres nearly always indicate a combination defect of respiratory complexes I and IV. Increased punctate lipid within myofibers is a regular feature of Kearns-Sayre and PEO, but not of MELAS and MERRF. Total deficiency of succinate dehydrogenase indicates a severe defect in Complex II; total absence of cytochrome-c-oxidase activity in all myofibres correlates with a severe deficiency of Complex IV or of coenzyme-Q10. The selective loss of cytochrome-c-oxidase activity in scattered myofibers, particularly if accompanied by strong succinate dehydrogenase staining in these same fibres, is good evidence of mitochondrial cytopathy and often of a significant mtDNA mutation, though not specific for Complex IV disorders. Glycogen may be excessive in ragged-red zones. Ultrastructure provides morphological evidence of mitochondrial cytopathy, in axons and endothelial cells as well as myocytes. Abnormal axonal mitochondria may contribute to neurogenic atrophy of muscle, a secondary chronic feature. Quantitative determinations of respiratory chain enzyme complexes, with citrate synthase as an internal control, confirm the histochemical impressions or may be the only evidence of mitochondrial disease. Biological and technical artifacts may yield falsely low enzymatic activities. Genetic studies screen common point mutations in mtDNA. The brain exhibits characteristic histopathological alterations in mitochondrial diseases. Skin biopsy is useful for mitochondrial ultrastructure in smooth erector pili muscles and axons; skin fibroblasts may be grown in culture. Mitochondrial alterations occur in many nonmitochondrial diseases and also may be induced by drugs and toxins.

scholarly journals Biochemical heterogeneity of rat liver mitochondria separated by rate zonal centrifugation

1972 ◽  
Vol 129 (1) ◽  
pp. 209-218 ◽  
Author(s):  
M. A. Wilson ◽  
J. Cascarano
Keyword(s):  
Cytochrome C ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Cytochrome B ◽  
Rat Liver ◽  
Nadh Dehydrogenase ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Osmotic Gradient ◽  
Glycerophosphate Dehydrogenase

1. Rat liver mitochondria were separated on the basis of their sedimentation coefficients in an iso-osmotic gradient of Ficoll–sucrose by rate zonal centrifugation. The fractions (33, each of 40ml) were collected in order of decreasing density. Fractions were analysed by spectral analysis to determine any differences in the concentrations of the cytochromes and by enzyme analyses to ascertain any differences in the activities of NADH dehydrogenase, succinate dehydrogenase and α-glycerophosphate dehydrogenase. 2. When plotted as% of the highest specific concentration, the contents of cytochrome a+a3 and cytochrome c+c1 were constant in all fractions but cytochrome b was only 65% of its maximal concentration in fraction 7 and increased with subsequent fractions. As a result, the cytochrome b/cytochrome a+a3 ratio almost doubled between fractions 7 and 25 whereas the cytochrome c+c1/cytochrome a+a3 ratio was unchanged. 3. Expression of the dehydrogenase activities as% of highest specific activity showed the following for fractions 6–26: NADH dehydrogenase activity remained fairly constant in all fractions; succinate dehydrogenase activity was 62% in fraction 6 and increased steadily to its maximum in fraction 18 and then decreased; the activity of α-glycerophosphate dehydrogenase was only 53% in fraction 6 and increased slowly to its peak in fractions 22 and 24. 4. These differences did not result from damaged or fragmented mitochondria or from microsomal contamination. 5. These results demonstrate that isolated liver mitochondria are biochemically heterogeneous. The importance of using a system for separating biochemically different mitochondria in studies of mitochondrial biogenesis is discussed.

scholarly journals Altered glycolytic and oxidative capacities of skeletal muscle contribute to insulin resistance in NIDDM

1997 ◽  
Vol 83 (1) ◽  
pp. 166-171 ◽  
Author(s):  
Jean-Aimé Simoneau ◽  
David E. Kelley
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Enzyme Activities ◽  
Glycolytic Enzymes ◽  
Oxidative Enzyme ◽  
Oxidative Enzymes ◽  
Glucose Tolerant

Simoneau, Jean-Aimé, and David E. Kelley. Altered glycolytic and oxidative capacities of skeletal muscle contribute to insulin resistance in NIDDM. J. Appl. Physiol. 83(1): 166–171, 1997.—The insulin resistance of skeletal muscle in glucose-tolerant obese individuals is associated with reduced activity of oxidative enzymes and a disproportionate increase in activity of glycolytic enzymes. Because non-insulin-dependent diabetes mellitus (NIDDM) is a disorder characterized by even more severe insulin resistance of skeletal muscle and because many individuals with NIDDM are obese, the present study was undertaken to examine whether decreased oxidative and increased glycolytic enzyme activities are also present in NIDDM. Percutaneous biopsy of vatus lateralis muscle was obtained in eight lean (L) and eight obese (O) nondiabetic subjects and in eight obese NIDDM subjects and was assayed for marker enzymes of the glycolytic [phosphofructokinase, glyceraldehyde phosphate dehydrogenase, hexokinase (HK)] and oxidative pathways [citrate synthase (CS), cytochrome- c oxidase], as well as for a glycogenolytic enzyme (glycogen phosphorylase) and a marker of anaerobic ATP resynthesis (creatine kinase). Insulin sensitivity was measured by using the euglycemic clamp technique. Activity for glycolytic enzymes (phosphofructokinase, glyceraldehye phosphate dehydrogenase, HK) was highest in subjects with subjects with NIDDM, following the order of NIDDM > O > L, whereas maximum velocity for oxidative enzymes (CS, cytochrome- c oxidase) was lowest in subjects with NIDDM. The ratio between glycolytic and oxidative enzyme activities within skeletal muscle correlated negatively with insulin sensitivity. The HK/CS ratio had the strongest correlation ( r = −0.60, P < 0.01) with insulin sensitivity. In summary, an imbalance between glycolytic and oxidative enzyme capacities is present in NIDDM subjects and is more severe than in obese or lean glucose-tolerant subjects. The altered ratio between glycolytic and oxidative enzyme activities found in skeletal muscle of individuals with NIDDM suggests that a dysregulation between mitochondrial oxidative capacity and capacity for glycolysis is an important component of the expression of insulin resistance.

scholarly journals The kinetics of enzyme changes in yeast under conditions that cause the loss of mitochondria

1968 ◽  
Vol 107 (4) ◽  
pp. 455-465 ◽  
Author(s):  
C. Chapman ◽  
W Bartley
Keyword(s):  
Cytochrome C ◽  
Glutamate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Nadh Oxidase ◽  
Isocitrate Lyase ◽  
Lag Phase ◽  
Glutamate Oxaloacetate Transaminase ◽  
Oxoglutarate Dehydrogenase ◽  
Nadh Cytochrome ◽  
Glucose 6 Phosphate Dehydrogenase

1. Aerobically grown yeast having a high activity of glyoxylate-cycle, citric acid-cycle and electron-transport enzymes was transferred to a medium containing 10% glucose. After a lag phase of 30min. the yeast grew exponentially with a mean generation time of 94min. 2. The enzymes malate dehydrogenase, isocitrate lyase, succinate–cytochrome c oxidoreductase and NADH–cytochrome c oxidoreductase lost 45%, 17%, 27% and 46% of their activity respectively during the lag phase. 3. When growth commenced pyruvate kinase, pyruvate decarboxylase, alcohol dehydrogenase, glutamate dehydrogenase (NADP+-linked) and NADPH–cytochrome c oxidoreductase increased in activity, whereas aconitase, isocitrate dehydrogenase (NAD+- and NADP+-linked), α-oxoglutarate dehydrogenase, fumarase, malate dehydrogenase, succinate–cytochrome c oxidoreductase, NADH–cytochrome c oxidoreductase, NADH oxidase, NADPH oxidase, cytochrome c oxidase, glutamate dehydrogenase (NAD+-linked), glutamate–oxaloacetate transaminase, isocitrate lyase and glucose 6-phosphate dehydrogenase decreased. 4. During the early stages of growth the loss of activity of aconitase, α-oxoglutarate dehydrogenase, fumarase and glucose 6-phosphate dehydrogenase could be accounted for by dilution by cell division. The lower rate of loss of activity of isocitrate dehydrogenase (NAD+- and NADP+-linked), glutamate dehydrogenase (NAD+-linked), glutamate–oxaloacetate transaminase, NADPH oxidase and cytochrome c oxidase implies their continued synthesis, whereas the higher rate of loss of activity of malate dehydrogenase, isocitrate lyase, succinate–cytochrome c oxidoreductase, NADH–cytochrome c oxidoreductase and NADH oxidase means that these enzymes were actively removed. 5. The mechanisms of selective removal of enzyme activity and the control of the residual metabolic pathways are discussed.

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