title: Calix[4]arene C-90 selectively inhibits Ca2+,Mg2+-ATPase of myometrium cell plasma membrane.
abstract: The supramolecular compound calix[4]arene C-90 (5,11,17,23-tetra(trifluoro)methyl(phenylsulfonylimino)-methylamino-25,26,27,28-tetrapropoxycalix[4]arene) is shown to efficiently inhibit the ATP hydrolase activity of Ca2+,Mg2+-ATPase in the myometrium cell plasma membrane fraction and also in a preparation of the purified enzyme solubilized from this subcellular fraction. The inhibition coefficient I0.5 values were 20.2 ± 0.5 and 58.5 ± 6.4 µM for the membrane fraction and the solubilized enzyme, respectively. The inhibitory effect of calix[4]arene C-90 was selective comparatively to other ATPases localized in the plasma membrane: calix[4]arene C-90 did not influence the activities of Na+,K+-ATPase and "basal" Mg2+-ATPase. The inhibitory effect of calix[4]arene C-90 on the Ca2+,Mg2+-ATPase activity was associated with the cooperative action of four trifluoromethylphenylsulfonylimine (sulfonylamidine) groups oriented similarly on the upper rim of the calix[4]arene macrocycle (the calix[4]arene "bowl"). The experimental findings seem to be of importance for studies, using calix[4]arene C-90, of membrane mechanisms of regulation of calcium homeostasis in smooth muscle cells and also for investigation of the participation of the plasma membrane Ca2+-pump in control of electro- and pharmacomechanical coupling in myocytes.
authors: Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kiev, 01601, Ukraine. veklich@biochem.kiev.ua.
authors: T A
authors: TA
authors: Veklich
authors: A A
authors: AA
authors: Shkrabak
authors: N N
authors: NN
authors: Slinchenko
authors: I I
authors: II
authors: Mazur
authors: R V
authors: RV
authors: Rodik
authors: V I
authors: VI
authors: Boyko
authors: V I
authors: VI
authors: Kalchenko
authors: S A
authors: SA
authors: Kosterin
mesh_terms: D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D047250:Calixarenes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology* / Q000378:metabolism; D005260:Female; D007700:Kinetics; D032389:Myocytes, Smooth Muscle / Q000201:enzymology / Q000378:metabolism; D009215:Myometrium / Q000166:cytology / Q000378:metabolism*; D010636:Phenols / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D013552:Swine
chemical_list: D010636:Phenols; C121325:calix(4)arene; D047250:Calixarenes; D017301:Ca(2+) Mg(2+)-ATPase