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 Reaction of caa3-type terminal cytochrome oxidase from the thermophilic bacterium PS3 with oxygen and carbon monoxide at low temperatures

1984 ◽  
Vol 221 (2) ◽  
pp. 529-533 ◽  
Author(s):  
N Sone ◽  
A Naqui ◽  
C Kumar ◽  
B Chance
Keyword(s):  
Activation Energy ◽  
Carbon Monoxide ◽  
Cytochrome Oxidase ◽  
Low Temperatures ◽  
Thermophilic Bacterium ◽  
Reduced Form ◽  
Compound A ◽  
First Order ◽  
First Order Kinetics ◽  
Higher Temperature

Reaction of O2 and CO with a caa3-type terminal cytochrome oxidase (EC 1.9.3.1) from the thermophilic bacterium PS3 grown with high aeration was studied at low temperatures. The CO recombination at the temperature range studied (−50 degrees C to −80 degrees C) followed first-order kinetics with an activation energy of 29.3 kJ/mol (7.0 kcal/mol). In the presence of O2 at −113 degrees C the photolysed reduced form binds O2 to form an ‘oxy’ intermediate similar to Compound A. At a higher temperature (-97 degrees C) another intermediate, similar to Compound B, is formed as a result of electron transfer from the enzyme to the liganded O2.

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 Upstream – News in Genomics

2002 ◽  
Vol 3 (3) ◽  
pp. 221-225
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ovarian Cancer ◽  
Oryza Sativa ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Proteomic Analysis ◽  
Large Scale ◽  
Protein Complexes ◽  
The Other ◽  
Blood Samples

In recent months a bumper crop of genomes has been completed, including the fission yeast (Schizosaccharomyces pombe) and rice (Oryza sativa). Two large-scale studies ofSaccharomyces cerevisiaeprotein complexes provided a picture of the eukaryotic proteome as a network of complexes. Amongst the other stories of interest was a demonstration that proteomic analysis of blood samples can be used to detect ovarian cancer, perhaps even as early as stage I.

scholarly journals Analysis of centromeric DNA in the fission yeast Schizosaccharomyces pombe.

1986 ◽  
Vol 83 (21) ◽  
pp. 8253-8257 ◽  
Author(s):  
L. Clarke ◽  
H. Amstutz ◽  
B. Fishel ◽  
J. Carbon
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Centromeric Dna

Transport of l-lysine in the fission yeast Schizosaccharomyces pombe

1989 ◽  
Vol 978 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Hana Sychrová ◽  
Jaroslav Horák ◽  
Arnošt Kotyk
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast

scholarly journals Assembly of normal actomyosin rings in the absence of Mid1p and cortical nodes in fission yeast

2008 ◽  
Vol 183 (6) ◽  
pp. 979-988 ◽  
Author(s):  
Yinyi Huang ◽  
Hongyan Yan ◽  
Mohan K. Balasubramanian
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Ring Structure ◽  
Contractile Ring ◽  
Ring Assembly ◽  
Cell Biol ◽  
In Cells

Cytokinesis in many eukaryotes depends on the function of an actomyosin contractile ring. The mechanisms regulating assembly and positioning of this ring are not fully understood. The fission yeast Schizosaccharomyces pombe divides using an actomyosin ring and is an attractive organism for the study of cytokinesis. Recent studies in S. pombe (Wu, J.Q., V. Sirotkin, D.R. Kovar, M. Lord, C.C. Beltzner, J.R. Kuhn, and T.D. Pollard. 2006. J. Cell Biol. 174:391–402; Vavylonis, D., J.Q. Wu, S. Hao, B. O'Shaughnessy, and T.D. Pollard. 2008. Science. 319:97–100) have suggested that the assembly of the actomyosin ring is initiated from a series of cortical nodes containing several components of this ring. These studies have proposed that actomyosin interactions bring together the cortical nodes to form a compacted ring structure. In this study, we test this model in cells that are unable to assemble cortical nodes. Although the cortical nodes play a role in the timing of ring assembly, we find that they are dispensable for the assembly of orthogonal actomyosin rings. Thus, a mechanism that is independent of cortical nodes is sufficient for the assembly of normal actomyosin rings.

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