A new phospholipase A2 inhibitor, unrelated to substrate analogues: kinetic characterization of the inhibition of secretory phospholipases A2 by PMS 832.
Starting from a series of compounds which were known to be PAF antagonists, we have synthesized molecules that are good inhibitors of PLA2s of groups I or II, with IC50 in the micromolar range (Binisti et al., 1997). In this report we investigate the mechanism of inhibition of bovine and porcine pancreatic phospholipases A2 (group I), and platelet lysate phospholipase A2 (group II) by one of these compounds, 1-(4'-methoxybenzoyl)-2-n-tridecylpiperazine (PMS 832). We show that PMS 832 behaves as a reversible, competitive inhibitor, with Ki values of 4.1 +/- 1.2 and 1.5 +/- 0.4 microM for porcine pancreatic phospholipase A2 and platelet lysate phospholipase A2, respectively. PMS 832 failed to inhibit platelet activation induced by several agonists and was also found to be inactive towards phospholipase C from Bacillus cereus, indicating a high specificity for phospholipase A2 inactivation. Thus, PMS 832 and its derivatives could serve as interesting tools to investigate the role of extracellular phospholipases A2 in inflammatory processes, and may be useful in the development of new anti-inflammatory agents.
Binisti
C
C
Universite Paris 7-Denis Diderot, Unité de Recherches Chimie et Pharmacologie, France.
Mounier
C
C
Touboul
E
E
Heymans
F
F
Bon
C
C
Godfroid
J J
JJ
D000818:Animals; D001407:Bacillus / Q000201:enzymology; D001792:Blood Platelets / Q000201:enzymology; D002417:Cattle; D002855:Chromatography, Thin Layer; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000378:metabolism; D007700:Kinetics; D008297:Male; D015394:Molecular Structure; D010179:Pancreas / Q000201:enzymology; D010712:Phosphatidic Acids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism; D010741:Phospholipases A / Q000037:antagonists & inhibitors* / Q000378:metabolism; D054467:Phospholipases A2; D010879:Piperazines / Q000737:chemistry / Q000494:pharmacology*; D010972:Platelet Activating Factor / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013552:Swine
C107839:1-(4'-methoxybenzoyl)-2-n-tridecylpiperazine; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D010879:Piperazines; D010972:Platelet Activating Factor; D012710:Serum Albumin, Bovine; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2