Kinetics of inhibitory effect of calix[4]arene С-90 on activity of transporting plasma membrane Cа(2+),Mg(2+)-ATPase of smooth muscle cells

Autor: Roman V. Rodik, Vitaly I. Kalchenko, Kosterin So, Veklich To, Iu Iu Mazur, Shkrabak Oa
Rok vydání: 2014
Předmět:
Zdroj: Ukrainian Biochemical Journal, Vol 86, Iss 5, Pp 37-46 (2014)
ISSN: 2409-4943
DOI: 10.15407/ubj86.05.037
Popis: 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.
Databáze: OpenAIRE