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Information × Registration Number 0212U009067, 0111U007135 , R & D reports Title Calixarenes as effectors of ATP-hydrolase of smooth muscle cell plasma membrane popup.stage_title Head Shkrabak Alexandr, Registration Date 29-12-2012 Organization A.V.Palladin Institute of Biochemistry of National Academy of Sciences popup.description2 The objects of investigation are Са2+,Mg2+-АТРase and Na+,K+-АТРase activities of smooth muscle cell plasma membrane. The aim of investigation was studying of lows and mechanisms of some calixarene influence on Са2+,Mg2+-АТРase and Na+,K+-АТРase activities of myometrium cell plasma membrane. We have shown that calixarene C-90 inhibited the Ca2+,Mg2+-ATPase; the apparent constant of inhibition by this calixarene was 20 µM. This influence was selective relative to other ATPases of plasma membrane. Calixarene C-90 decresed turnover number and affinity of Са2+,Mg2+-АТРase to Ca and Mg ions, bat did not influenced on affinity to ATP. Besides, efficiency of Са2+,Mg2+-АТРase inhibition increased by decreasing of Ca and Mg ion concentration. The calixarene C-150 - the calixarene "scaffold" without any substituents on the upper rim of the macrocycle, and the compound М-1 - a fragment of the calixarene С-90 had practically no influence on the enzymatic activities of Ca2+,Mg2+-ATPase. Hence, the influence of calixarene С-90 on the enzymatic activity was caused by the cooperative action of substituents on the upper rim of the calixarene. We have shown that calixarenes C-715 and C-716 which are structural analogs of calixaren C-90 could not effective inhibit the Ca2+,Mg2+-ATPase. Namely, calixarenes C-715 (100 µM) decreased mentioned enzyme only to 80 %, calixarenes C-716 inhibited this enzeyne with constant 53,4 ± 3,6 µM. Analyzing the structure difference of these calixarenes we came to conclusion that at least two phenilsulphonic substituents on the upper rim of calixarene are necessary for inhibition of Ca2+,Mg2+-ATPase. The structural analogs of calixaren C-99, which differ by quantity of substituents on lower rim of calixarene were less effective inhibitors of Na+,K+-АТРase of myimetrtium than calixaren C-99. Inhibitory properties and efficiency of inhibitory action of mentioned calixarene caused by chemical nature, quantity and conformation of substituents on the upper rim of calixarene macrocycle. The results of our investigation can be foundation for creation of effective inhibitors of Ca2+,Mg2+-ATPase. It is important for further investigation of coupling mechanisms in muscles. Besides, new pharmaceuticals on the base of calixarenes can be created in order to regulate muscle contractility in case of their dysfunction during pathology. Keywords: myometrium, plasma membrane, Ca2+,Mg2+-ATPase, Na+,K+-АТРase, calyx[4]arenes. Product Description popup.authors Коломієць Оксана Валеріївна popup.nrat_date 2020-04-02 Close