Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

• Published in: Ukrainian biochemical journal Vol. 95; no. 6; pp. 5 - 20
• Main Authors: Veklich, Т. О., Rodik, R. V., Tsymbalyuk, О. V., Shkrabak, О. V., Maliuk, O. V., Karakhim, S. O., Vyshnevskyi, S. H., Kalchenko, V. І., Kosterin, S. O.
• Format: Journal Article
• Language: English
• Published: National Academy of Sciences of Ukraine, Palladin Institute of Biochemistry 14.12.2023
• Subjects: contraction-relaxation mechanokinetics; cytosolic ca(2+); myometrium; plasma membrane са(2+)‚mg(2+)-атрase; smooth muscle cell; thiacalixarene
• ISSN: 2409-4943; 2413-5003
• DOI: 10.15407/ubj95.06.005

The enzymatic and kinetic analyses were used to demonstrate that 5,11,17,23-tetra(trifluoro)methyl(phenylsulfonylimino)methylamino-25,27-dihexyloxy-26,28-dihydroxythiacalix[4]arene С-1087 effectively inhibited the Са2+,Mg2+-АТРase activity of the rat myometrium cells plasma membrane (І0.5 = 9.4 ± 0.6 µM) with no effect on the relative activity of other membrane ATPases. With the use of confocal microscopy and Ca2+-sensitive fluorescent probe fluo-4, it was shown that the application of thiacalix[4]arene С-1087 to the immobilized uterus myocytes increased the cytosolic concentration of Ca2+. Tenzometric studies of rat uterus smooth muscles with the subsequent mechanokinetic analysis revealed that thiacalix[4]arene С-1087 considerably decreased the maximal velocity of the relaxation of both spontaneous contractile response and contraction induced by hyperpotassium solution. Keywords: contraction-relaxation mechanokinetics, cytosolic Ca(2+), myometrium, plasma membrane Са(2+)‚Mg(2+)-АТРase, smooth muscle cell, thiacalix[4]arene