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'Pyruvate' in keywords
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1986 (1)
1984 (1)
1Author    Ahlert SchmidtRequires cookie*
 Title    Occurrence of Mercaptopyruvate Sulfotransferase Activity in Photosynthetic Organisms  
 Abstract    Mercaptopyruvate sulfotransferase activity catalyzes the formation o f pyruvate from mercapto­ pyruvate in the presence o f suitable reagents as acceptor. It was detected in Lemna minor, Pisum sativum, Spinacia oleracea, Chlorella fusca, Synechococcus 6301, and Rhodopseudomonas palustris. Best activity was detected using dithioerythritol as a thiol reagent; good activity was obtained using mercaptoethanol, glutathione, mercaptopyruvate or sulfite as acceptor. The pH-optimum for the Chlorella mercaptopyruvate sulfotransferase was found around 9; the apparent Km for mercaptopyruvate was determined to 2 m M and for dithioerythritol for 5 m M using crude Chlorella extracts. The role of this enzyme is discussed in relation to cysteine catabolism by photosynthetic organisms. 
  Reference    Z. Naturforsch. 39c, 916—921 (1984); received April 6 1984 
  Published    1984 
  Keywords    Pyruvate, Mercaptopyruvate, Lemna, Spinacia, Pisum, Chlorella, Synechococcus, Rhodopseudomonas 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0916.pdf 
 Identifier    ZNC-1984-39c-0916 
 Volume    39 
2Author    W. Erner, K. Roll, StefanP. Ostius, F. Riedhelm, S. ChneiderRequires cookie*
 Title    Proliferation Kinetics and Metabolic Features of in vitro Grown Ehrlich Ascites Tumor Cells in the Presence of Exogenous Pyruvate  
 Abstract    The proliferation o f in vitro grown Ehrlich ascites tum or cells is inhibited by pyruvate concen­ trations > 2 m M . In the presence o f 4 —5 m M pyruvate the growth is reduced to about 50% , in the presence o f 20 mM to about 5 — 10%. Viability o f the cells is not severely affected. Increase o f D N A corresponds to the cell growth. On recultivation in pyruvate free standard m edium , growth is nearly normal. Flow cytometric analyses o f the proliferation kinetics of the cells in the presence o f 20 m M pyruvate revealed a retardation o f the passage o f all phases o f the cell cycle. N o phase specific effects could be detected though the S-and G 2M -p hase are more afflicted than G l . The growth inhibition o f E A T cells by pyruvate seem s to depend on the presence of glucose. Exogenous pyruvate (> 1 —2 m M) causes an activation o f pyruvate dehydrogenase, a reduction o f lactate production from glucose and a stimulation o f lipid biosynthesis; the N A D /N A D H ratio of the cells is reduced and a rise o f glycolytic interm ediates beyond glyceraldehyde-3-phosphate dehydrogenase is observed. Maximal activation of pyruvate dehydrogenase by non toxic concen­ trations o f dichloroacetate is also accom pagnied by an inhibition o f cell growth. It is suggested that an increase o f glyceraldehyde-3-phosphate level and the changes in the redox state o f the cells are o f relevance for the inhibition o f cell growth by pyruvate. 100—500 ^im exogenous glycer-aldehyde-3-phosphate strongly inhibited cell growth. 
  Reference    Z. Naturforsch. 41c, 787—794 (1986); received March 20 1986 
  Published    1986 
  Keywords    Ehrlich A scites Tumor Cells, Growth Inhibition, Pyruvate, M etabolism 
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 TEI-XML for    default:Reihe_C/41/ZNC-1986-41c-0787.pdf 
 Identifier    ZNC-1986-41c-0787 
 Volume    41