HMN-709, a chlorobenzenesulfonamide derivative, is a new membrane-permeable calmodulin antagonist.
Our objective is to describe the basic chemical and biological properties of the new calmodulin antagonist HMN-709 (2-[N-(2-aminoethyl)-N-(4-chlorobenzenesulfonyl)]amino-N-(4-flu orocinnamyl)-N-methylbenzylamine). This newly synthesized compound was found to inhibit the Ca2+/calmodulin-dependent activation of calmodulin kinase I, smooth muscle myosin light chain kinase and Ca2+-phosphodiesterase with IC50 values of 1.57+/-0.21, 2.29+/-0.09 and 0.30+/-0.08 microM (mean+/-S.E.), respectively. This compound showed little or no effect on the Ca2+/calmodulin-independent activation of protein kinase A, protein kinase C and basal phosphodiesterase. In addition, HMN-709 inhibited calmodulin kinase I competitively with respect to calmodulin (Ki=0.88 microM) and non-competitively with respect to ATP. Affinity chromatography, with HMN-709-coupled Sepharose HP, showed that the compound bound to calmodulin in a Ca(2+)-dependent manner and did not bind to calmodulin kinase I. These results suggest that HMN-709 antagonizes calmodulin by binding to Ca2+/calmodulin. HMN-709 inhibited collagen-induced platelet aggregation with an IC50 value of 11.80+/-0.86 microM (mean+/-S.E.) without inhibiting phorbol 12,13-dibutyrate-induced aggregation at doses up to 12 microM. HMN-709 appears to be a new, membrane-permeable calmodulin antagonist that may be used for studying the involvement of calmodulin in cellular processes.
The Department of Pharmacology, Nagoya University School of Medicine, Showa-ku, Japan.
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H
Yokokura
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Okada
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Terada
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Hidaka
D000818:Animals; D001596:Benzylamines / Q000737:chemistry / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D002147:Calmodulin / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D010539:Permeability; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D012701:Serotonin / Q000032:analysis / Q000378:metabolism; D013449:Sulfonamides / Q000737:chemistry / Q000494:pharmacology*
D001596:Benzylamines; D002147:Calmodulin; C102875:HMN 709; D010726:Phosphodiesterase Inhibitors; D010975:Platelet Aggregation Inhibitors; D013449:Sulfonamides; D012701:Serotonin; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases