Fluorimetric analysis of phospholipase activity in Tetrahymena pyriformis GL.

Péter Kovács, György Csaba

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6 Citations (Scopus)


The unicellular Tetrahymena enzymatically split the synthetic phosphodiester, 4-methylumbelliferyl phosphocoline substrate. The enzyme activity was completely blocked in vitro and drastically inhibited in vivo by G-protein activating fluorides (NaF; AlF4/- and BeF3/-). The phospholipase A2 inhibitor, quinacrine, and the protein phosphatase inhibitor, neomycin, inhibited the enzyme activity in vitro and activated it in vivo. Another phospholipase A2 inhibitor 4-bromo phenacyl bromide was ineffective in vivo and in vitro alike, as well as the cyclooxygenase inhibitor indomethacin. Results of these experiments indicate that some treatments could be specific for a well defined activity (e.g., phospholipase A2, G-protein) but subject to influence by other enzymes (e.g., phospholipase C, sphingomyelinase). The experiments call attention to the differences in the results of the in vivo and in vitro studies.

Original languageEnglish
Pages (from-to)81-87
Number of pages7
JournalBioscience Reports
Issue number2
Publication statusPublished - Jul 27 1999



  • PLA
  • PLA-inhibitors
  • PLC
  • PLC-inhibitors
  • Signaling
  • Tetrahymena

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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