Tag Archives: thiacalix[4]arene
A new affine inhibitor of sodium pump thiacalix[4]arene С-1193 increases the intracellular concentration of Ca ions and modifies myometrium contractility
Т. О. Veklich1*, S. О. Cherenok2, О. V. Tsymbalyuk3, О. A. Shkrabak1,
S. O. Karakhim1, A. I. Selihova2, V. І. Kalchenko2, S. O. Kosterin1
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
*e-mail: veklich@biochem.kiev.ua;
2Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
3Educational and Scientific Institute of High Technologies,
Taras Shevchenko National University of Kyiv, Ukraine
Received: 16 June 2023; Revised: 31 September 2023;
Accepted: 27 October 2023; Available on-line: 06 November 2023
The methods of enzymatic and kinetic analysis were used to demonstrate that thiacalix[4]arene-bis-hydroxymethylphosphonic acid С-1193 had the inhibitory effect (І0.5 = 42.1 ± 0.6 nM) on Na+,K+-ATPase activity in the plasma membrane of myometrium cells with no effect on the relative activity of other ATPases localized in this subcellular structure. The method of confocal microscopy and Са2+-sensitive fluorescent probe fluo-4 were used to demonstrate that thiacalix[4]arene С-1193 increased the intracellular concentration of Ca ions in the immobilized uterine myocytes. The tenzometric studies proved that С-1193 (10 and 100 μМ) increased the isometric phasic contractions, induced via the paths of both electromechanical (depolarization with high-potassium solution) and pharmacomechanical (application of uterotonic hormone oxytocin, neurotransmitter acetylcholine or selective agonist of muscarinic acetylcholine receptors cevimeline) coupling. Application of thiacalix[4]arene С-1193 as a selective and effective inhibitor of Nа+,K+-ATPase may be useful both for studyng the regulation of ion homeostasis in smooth muscle cells and creation of new uterotonics based on the calixarene core.
Тhiacalix[4]arene phosphonate C-800 as a novel fluorescent probe for zinc in living cells
V. I. Yavorovska1, R. D. Labyntseva1*, O. V. Bevza1, A. Y. Pugach1,
A. B. Drapailo2, S. O. Cherenok2, V. I. Kalchenko2, S. O. Kosterin1
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
*e-mail: raisa.lab@gmail.com
Received: 07 April 2021; Accepted: 07 July 2021
Zn ions are significant for maintaining the proper human organism functioning, thus monitoring the zinc content in living cells and the development of sensitive tracking systems and sensors for Zn is particularly important. The purpose of the work was to study the properties of synthetic thiacalix[4]arene C-800 (5,11,17,23-tetrakis[(hydroxy-ethoxyphosphonyl)methyl])-25,26,27,28-tetrahydroxythiacalix[4]arene) as a fluorescent sensor for zinc ions in living cells. Our studies demonstrated that thiacalix[4]arene C-800 containing four hydroxy-ethoxyphosphonylmethyl groups on the upper rim exhibited fluorescent properties at 340 nm excitation wavelength. Fluorescence intensity of thiacalix[4]arene C-800 was increased significantly in the presence of Zn cations, while cations of other metals, such as Mg2+, Ca2+, Cd2+, and Pb2+ did not affect it. Computer modeling demonstrated that two Zn cations interact with the oxygen atoms of four hydroxy-ethoxyphosphonylmethyl groups. It was shown that thiacalix[4]arene C-800 quickly penetrated rat myometrial cells that led to an increased intracellular fluorescence level. The addition of Zn2+ to cells, stained with thiacalix[4]arene C-800, was followed an even greater increase of intracellular fluorescent signal intensity. No effect of thiacalix[4]arene C-800 on reactive oxygen species production in myometrial cells was detected as well as on cells viability in the range of its 50-250 μM concentrations. Thus, thiacalix[4]arene C-800 can potentially be used as a selective fluorescent probe for the detection of Zn2+ in living cells.