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 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 The reaction of cytochrome oxidase with oxygen in the fission yeast Schizosaccharomyces pombe 972h-. Studies at subzero temperatures and measurement of apparent oxygen affinity

1979 ◽  
Vol 184 (3) ◽  
pp. 555-563 ◽  
Author(s):  
R K Poole ◽  
D Lloyd ◽  
B Chance
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Cytochrome Oxidase ◽  
Flash Photolysis ◽  
Oxygen Affinity ◽  
Intermediate Compound ◽  
Reduced Form ◽  
Difference Spectra ◽  
Intact Cells ◽  
Compound A

1. Cytochrome alpha 3 in whole-cell suspensions of the fission yeast Schizosaccharomyces pombe reacted in the reduced form with CO to give a photodissociable CO complex with absorption maxima at 429, 543 and 591 nm in CO-liganded reduced-minus-reduced difference spectra. 2. Other CO-bound haemoproteins, cytochromes P-420 and P-450, were not photodissociated under the conditions employed. 3. Measurements of the rates of reassociation of CO with cytochrome alpha 3 after flash photolysis over the temperature range from −101 to −109 degrees C gave a value for Eact. of 28.6 kJ/mol. 4. Between −94 and −106 degrees C, O2 reacted with cytochrome oxidase in intact cells to give an oxygenated intermediate (compound A). 5. At −70 degrees C compound A was converted into a second spectrally distinct intermediate (compound B). 6. Electron transport, indicated by the oxidation of cytochromes alpha + alpha 3 and cytochrome c, did not occur until the temperature was raised to −50 degrees C. 7. At room temperature cytochfome oxidase was oxidized to 50% of its steady-state concentration by 0.35 microM-O2.

scholarly journals Operando Infrared Spectroscopy for the Analysis of Gas-processing Metalloenzymes

2020 ◽  
Author(s):  
Sven Timo Stripp
Keyword(s):  
Infrared Spectroscopy ◽  
Cytochrome C ◽  
Ambient Temperature ◽  
Cytochrome C Oxidase ◽  
Structural Changes ◽  
Attenuated Total Reflection ◽  
Invasive Technique ◽  
Difference Spectra ◽  
Gas Processing ◽  
Temperature And Pressure

Earth-abundant transition metals like iron, nickel, copper, molybdenum, and vanadium have been identified as essential constituents of the cellular gas metabolism in all kingdoms of life. Associated with biological macromolecules, gas-processing metalloenzymes (GPMs) are formed that catalyse a variety of redox reactions. This includes the reduction of O2 to water by cytochrome c oxidase (‘complex IV’), the reduction of N2 to NH4 by nitrogenase, as well as the reduction of protons to H2 (and oxidation of the later) by hydrogenase. GPMs perform at ambient temperature and pressure, in the presence of water, and often extremely low educt concentrations, thus serving as natural examples for efficient catalysis. Facilitating the design of biomimetic catalysts, biophysicist thrive to understand the reaction principles of GPMs making use of various techniques. In this perspective, I will introduce Fourier-transform infrared spectroscopy in attenuated total reflection configuration (ATR FTIR) for the analysis of GPMs like cytochrome c oxidase, nitrogenase, and hydrogenase. Infrared spectroscopy provides information about the geometry and redox state of the catalytic cofactors, the protonation state of amino acid residues, the hydrogen-bonding network, and protein structural changes. I developed an approach to probe and trigger the reaction of GPMs by gas exchange experiments, exploring the reactivity of these enzymes with their natural reactants. This allows recording sensitive ATR FTIR difference spectra with seconds time resolution. Finally yet importantly, infrared spectroscopy is an electronically non-invasive technique that allows investigating protein samples under biologically relevant conditions, i.e., at ambient temperature and pressure, and in the presence of water.

Reduction of cytochrome-c oxidase copper precedes failing cerebral O2 utilization in fluorocarbon-perfused cats

1996 ◽  
Vol 271 (2) ◽  
pp. H579-H587 ◽  
Author(s):  
R. Stingele ◽  
B. Wagner ◽  
M. V. Kameneva ◽  
M. A. Williams ◽  
D. A. Wilson ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Redox State ◽  
Near Infrared ◽  
Hypoxic Conditions ◽  
Sagittal Sinus ◽  
Tissue Po2 ◽  
Relationship Of ◽  
The Relationship

We determined the relationship of the low-potential copper (CuA) redox state of cytochrome-c oxidase to the brain tissue PO2 (PtiO2) and global cerebral O2 consumption (CMRO2) in vivo. The redox state of cytochrome-c oxidase copper was monitored in perfluorocarbon-exchanged cats under normoxic and graded hypoxic conditions with use of near-infrared spectroscopy. Continuous spectra ranging from 730 to 960 nm were acquired, and the change in copper redox state was assessed by the absorption changes at 830 nm. PtiO2 was measured with O2-sensitive electrodes implanted into the cortex, and CMRO2 was determined by sampling arterial and superior sagittal sinus perfusate and by measuring blood flow with radiolabeled microspheres. As PtiO2 decreased with hypoxia, the CuA of cytochrome-c oxidase became progressively reduced, whereas the CMRO2 was unchanged during the initial stages of hypoxia. Only with severe hypoxia, did CMRO2 and the amplitude of somatosensory evoked potentials decrease. We conclude that the CuA site of cytochrome-c oxidase is involved in a regulatory adjustment that helps maintain CMRO2 constant.

IR signatures of the metal centres of bovine cytochrome c oxidase: assignments and redox-linkage

2013 ◽  
Vol 41 (5) ◽  
pp. 1242-1248 ◽  
Author(s):  
Raksha Dodia ◽  
Amandine Maréchal ◽  
Simona Bettini ◽  
Masayo Iwaki ◽  
Peter R. Rich
Keyword(s):  
Carbon Monoxide ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Redox Cycling ◽  
Difference Spectra ◽  
Redox States ◽  
Ir Bands ◽  
Specific Metal

Assignments of IR bands of reduced minus oxidized IR difference spectra of bovine and related cytochrome c oxidases are reviewed and their linkages to specific metal centres are assessed. To aid this, redox-poised difference spectra in the presence of cyanide or carbon monoxide are presented. These ligands fix the redox states of either haem a3 alone or haem a3 and CuB respectively, while allowing redox cycling of the remaining centres.

Neither respiration nor cytochrome c oxidase affects mitochondrial morphology in Saccharomyces cerevisiae.

1998 ◽  
Vol 201 (11) ◽  
pp. 1729-1737 ◽  
Author(s):  
C Church ◽  
R O Poyton
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Respiratory Chain ◽  
Glucose Repression ◽  
Nuclear Gene ◽  
Yeast Cells ◽  
Mitochondrial Proteins ◽  
Mitochondrial Morphology ◽  
Per Se ◽  
Mitochondrial Reticulum

Previous studies have reported that mitochondrial morphology and volume in yeast cells are linked to cellular respiratory capacity. These studies revealed that mitochondrial morphology in glucose-repressed or anaerobically grown cells, which lack or have reduced levels of respiration, is different from that in fully respiring cells. Although both oxygen deprivation and glucose repression decrease the levels of respiratory chain proteins, they decrease the expression of many non-mitochondrial proteins as well, making it difficult to determine whether it is a defect in respiration or something else that effects mitochondrial morphology. To determine whether mitochondrial morphology is dependent on respiration per se, we used a strain with a null mutation in PET100, a nuclear gene that is specifically required for the assembly of cytochrome c oxidase. Although this strain lacks respiration, the mitochondrial morphology and volumes are both comparable to those found in its respiration-proficient parent. These findings indicate that respiration is not involved in the establishment or maintenance of yeast mitochondrial morphology, and that the previously observed effects of oxygen availability and glucose repression on mitochondrial morphology are not exerted through the respiratory chain. By applying the principle of symmorphosis to these findings, we conclude that the shape and size of the mitochondrial reticulum found in respiring yeast cells is maintained for reasons other than respiration.

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