DY-9760e, a novel calmodulin antagonist with cytoprotective action.
We report the pharmacological characterization and cytoprotective effect of DY-9760e, 3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-( 4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate, a novel antagonist of calmodulin. DY-9760e inhibited calmodulin-dependent enzymes, including calmodulin-dependent protein kinase II and IV, calcineurin, [corrected]  calmodulin-dependent phosphodiesterase and myosin light chain kinase with Ki values of 1.4, 12, 2.0, 3.8 and 133 microM, respectively. These antagonistic effects of DY-9760e were more potent than those of W-7, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, another calmodulin antagonist. This compound showed little or no effect on calmodulin-independent enzymes, such as protein kinase A and C and calpain I and II. Analysis of the hydrophobic interaction of DY-9760e with calmodulin by using 2-p-toluidinylnaphthalene-6-sulfonate and 9-anthroylcholine revealed that, like W-7, DY-9760e bound to the hydrophobic regions of calmodulin. The [14C]DY-9760e binding assay indicated that DY-9760e bound to calmodulin at one class of binding site. Finally, DY-9760e substantially protected N1E-115 neuroblastoma cells from cytotoxicity induced by the Ca2+ ionophore, A23187. These results indicate that DY-9760e, a novel calmodulin antagonist, possesses a cytoprotective action and suggest that calmodulin plays a critical role in mediating some of the biochemical events leading to cell death following Ca2+ overload.
Sugimura
M
M
New Product Research Laboratories III, Daiichi Pharmaceutical Co., Ltd., Tokyo, Japan.
Sato
T
T
Nakayama
W
W
Morishima
Y
Y
Fukunaga
K
K
Omitsu
M
M
Miyamoto
E
E
Shirasaki
Y
Y
D000001:Calcimycin / Q000037:antagonists & inhibitors; D065095:Calcineurin Inhibitors; D002118:Calcium / Q000502:physiology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors*; D002147:Calmodulin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D007191:Indazoles / Q000494:pharmacology*; D007476:Ionophores / Q000037:antagonists & inhibitors; D009447:Neuroblastoma; D013449:Sulfonamides / Q000494:pharmacology; D014407:Tumor Cells, Cultured
C109602:3-(2-(4-(3-chloro-2-methylphenyl)1-piperazinyl)ethyl)5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazol dihydrochloride 3.5 hydrate; D065095:Calcineurin Inhibitors; D002147:Calmodulin; D007191:Indazoles; D007476:Ionophores; D013449:Sulfonamides; D000001:Calcimycin; C017967:W 7; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002118:Calcium