Fluorimetric analysis of phospholipase activity in Tetrahymena pyriformis GL.
The unicellular Tetrahymena enzymatically split the synthetic phosphodiester, 4-methylumbelliferyl phosphocholine substrate. The enzyme activity was completely blocked in vitro and drastically inhibited in vivo by G-protein activating fluorides (NaF; AIF4- 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.
Kovács
P
P
Department of Genetics, Cell and Immunobiology, Semmelweis University of Medicine, Budapest, Hungary.
Csaba
G
G
D000098:Acetophenones / Q000494:pharmacology; D017607:Aluminum Compounds / Q000494:pharmacology; D000818:Animals; D001608:Beryllium / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005459:Fluorides / Q000494:pharmacology; D005470:Fluorometry / Q000379:methods; D019204:GTP-Binding Proteins / Q000187:drug effects / Q000378:metabolism; D007213:Indomethacin / Q000494:pharmacology; D009355:Neomycin / Q000494:pharmacology; D010740:Phospholipases / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000378:metabolism*; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D011796:Quinacrine / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D013769:Tetrahymena pyriformis / Q000187:drug effects / Q000201:enzymology*; D010738:Type C Phospholipases / Q000187:drug effects / Q000378:metabolism
D000098:Acetophenones; D017607:Aluminum Compounds; D004791:Enzyme Inhibitors; C035982:beryllium fluoride; C013190:phenacyl bromide; D012969:Sodium Fluoride; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D011796:Quinacrine; D009355:Neomycin; D001608:Beryllium; D005459:Fluorides; D007213:Indomethacin; C032311:aluminum fluoride