THE CALIXARENE C-107 INCREASES THE AFFINITY OF THE Na+,K+-АТРase ACTIVITY
IN PLASMATIC MEMBRANE OF SMOOTH MUSCLE CELLS TO THE OUABAIN
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
In the experiments carried out with the suspension of the myometrium cell plasmatic membranes treated with 0.1% digitonin solution we investigated the influence of сalixarene С-107 (5,17-diamino(2-pyridyl)methylphosphono-11,23-di-tret-butyl-26,28-dihydroxy-25,27-dipropoxycalixarene) on the Nа+,K+-АТРase activity. It was shown that this calixarene increased the affinity of the enzyme for the sodium pump conventional inhibitor - ouabain: the magnitudes of the seeming constant of inhibition I0.5changed from 26.9 ± 1.3 mM to 10.9 ± 0.6 mM. However the ouabain itself did not influence on the affinity of the Nа+,K+-АТРase for сalixarene С-107.
Key words: Na+,K+-ATPase, Mg2+-ATPase, plasma membrane, smooth muscle cells, myometrium, enzymatic hydrolysis of ATP, kinetic properties of ATPase, calixarenes, aminophosphonic acids.
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