title: [Kinetics of inhibitory effect of calix[4]arene C-90 on activity of transporting plasma membrane Ca2+, Mg2+-ATPase of smooth muscle cells].
abstract: In experiments on the suspension of myometrium cell plasma membrane, processed by 0.1% digitonin, the inhibitory action of calix[4]arene C-90 (5,11,17,23-tetra(threeftor)methyl(phenilsulphonilimino)-methylamino-25,26,27,28-tetrapropoxy-calix[4]arene) on the activity of Ca2+,Mg2+-ATPase was investigated. The authors also examined the influence of calix[4]arene in different concentration on affinity of enzyme (Ca2,Mg2+-ATPase) for the ATP and ions of Mg and Ca, and its influence on cooperative effect and maximum velocity of ATP hydrolysis. It is shown that calix[4]arene does not influence the affinity of Ca2+,Mg2+-ATPase for the ATP, which means that these two compounds have different binding centers. Also calix[4]arene has no influence on affinity and cooperative effect of Ca ions, if it is used in concentration lower than 50 μM. Calix[4]arene slightly increases coefficient of Ca2+,Mg2+-ATPase activation by magnesium chloride. In all three cases, where ATP, Mg and Ca ions are used to test the impact of calix[4]arene, maximum velocity of ATP hydrolysis significantly decreases. All these results clarify that calix[4]arene implements its inhibitory action through mechanism of uncompetitive inhibition of Ca2+,Mg2+-ATPase activity.
authors: T O
authors: TO
authors: Veklich
authors: O A
authors: OA
authors: Shkrabak
authors: Iu Iu
authors: IuIu
authors: Mazur
authors: R V
authors: RV
authors: Rodik
authors: V I
authors: VI
authors: Kal'chenko
authors: S O
authors: SO
authors: Kosterin
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D047250:Calixarenes / Q000494:pharmacology*; D002413:Cations, Divalent; D002462:Cell Membrane / Q000187:drug effects* / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006868:Hydrolysis; D017136:Ion Transport / Q000187:drug effects; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism*; D015636:Magnesium Chloride / Q000494:pharmacology; D015394:Molecular Structure; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D009215:Myometrium / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D013552:Swine
chemical_list: D002413:Cations, Divalent; D015636:Magnesium Chloride; D047250:Calixarenes; D000255:Adenosine Triphosphate; D017301:Ca(2+) Mg(2+)-ATPase; D008274:Magnesium; D002118:Calcium