Tag Archives: smooth muscle cell
Kinetic regularities of thiacalix[4]arene C-1087 inhibitory effect on the activity of Mg(2+)-dependent Ca(2+)-transporting ATP hydrolase in the plasma membrane of smooth muscle cells
Т. О. Veklich1, О. V. Bevza1, О. V. Maliuk1*, S. О. Kosterin1,
R. V. Rodik2, S. H. Vyshnevskyi2, V. І. Kalchenko2
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
*e-mail: alexmaliukid@gmail.com;
2Institute of Organic Chemistry, National Academy of Sciences of Ukraine
Received: 05 November 2023; Revised: 04 January 2024;
Accepted: 01 February 2024; Available on-line: 26 February 2024
The experiments with the suspension of plasma membranes of myometrium cells, treated with 0.1% digitonin solution, were used to study kinetic regularities of the inhibitory effect of tetra-N-phenylsulfonyl trifluoroacetamidine-thiacalixarene (С-1087) on the activity of Са2+,Mg2+-ATPase. The studies demonstrated the impact of C-1087 on the cumulative effect and the maximal velocity of ATP hydrolysis. No effect of С-1087 on the affinity between Са2+,Mg2+-ATPase, and АТР, affinity and cumulative effect of Ca ions and activation coefficient for Mg ions was revealed. A considerable decrease in the maximal velocity of ATP hydrolysis evidenced a complete non-competitive mechanism of inhibiting Са2+,Mg2+-АТРase activity with thiacalix[4]arene С-1087. Computer simulation demonstrated that thiacalix[4]arene С-1087 inhibiting effect on Са2+,Mg2+-ATPase may be conditioned by the cumulative effect of four spatially oriented N-sulfonylamidine groups on the upper rim of its macrocyclic platform.
Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane
Т. О. Veklich1*, R. V. Rodik2, О. V. Tsymbalyuk3,
О. V. Shkrabak1, O. V. Maliuk1, S. O. Karakhim1,
S. H. Vyshnevskyi3, V. І. Kalchenko3, 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, Kyiv, Ukraine;
Received: 01 September 2023; Revised: 23 October 2023;
Accepted: 01 December 2023; Available on-line: 18 December 2023
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.
Inhibition of Na(+),K(+)-ATPase and activation of myosin ATPase by calix[4]arene C-107 cause stimulation of isolated smooth muscle contractile activity
T. O. Veklich1, R. D. Labyntseva1, O. A. Shkrabak1, O. V. Tsymbalyuk2,
R. V. Rodik3, V. I. Kalchenko3, S. O. Kosterin1
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2Institute of High Technologies, Taras Shevchenko National University of Kyiv, Ukraine;
3Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: veklich@biochem.kiev.ua; otsymbal@bigmir.net; manli@ioch.kiev.ua
Received: 04 Jule 2019; Accepted: 29 November 2019
The discovery of compounds that might modify myometrial contractility is an important area of researches. In our previous experiments, we found that some representatives of macrocyclic compounds family – calix[4]arenes – can modify the enzymatic and transport activity of membrane-bound cation-transport ATP hydrolases. The aim of this work was to study and compare the effect of calix[4]arene C-107 on the enzymatic activities of Mg2+-dependent ATPases of the uterine smooth muscle, namely: ouabain-sensitive Na+,K+-ATPase, plasma membrane Ca2+-independent “basal” Mg2+-ATPase, ATPase of the actomyosin complex and myosin subfragment-1, with effect on the contractile activity of the myometrium. It was shown that calix[4]arene C-107 efficiently inhibited myometrium Na+,K+-ATPase (I50 = 54 ± 6 nM) selectively to other ATP-hydrolases of the plasma membrane and simultaneously activated the enzymatic activity of the myosin ATPase of smooth muscles (A50 = 9.6 ± 0.7 μM). Such reciprocal biochemical effects led to the stimulation of the smooth muscle contractile activity that was demonstrated by the tensometric method using different isolated smooth muscles. Calix[4]arene С-107 was shown to stimulate the increase of the tonic component of myometrium contractions induced by oxytocin, as well as contractions of the caecum muscles induced by high-potassium solution or acetylcholine, and to maintain increased tension for a long time. Thus, calix[4]arene C-107 is a prospective compound for enhancing the smooth muscle basal tone and/or contraction in case of hypotonic dysfunctions.
Mg(2+),ATP-dependent plasma membrane calcium pump of smooth muscle cells. ІІ. Regulation of activity
T. О. Veklich, Iu. Iu. Mazur, S. О. Kosterin
Palladin Institute of Biochemistry, National Academy of Science of Ukraine, Kyiv;
e-mail: veklich@biochem.kiev.ua,
yuliya.vorona@gmail.com
Plasma membrane Ca2+-pump is one of key proteins, which takes part in Ca2+ exchange in smooth muscle cells. It has a lot of diverse functions from control of basal cytoplasmal Ca2+ concentration to regulation of proteins involved in Ca2+-dependent signal pathway. Ca2+ pump function is often dependent on the isoform or even form of alternative splicing. Allowing for a variety of Ca2+-pump functions and properties, which were reviewed in detail in the first part of our review article cycle (Ukr. Biochem. J., 2015; 87(1)), the precise control of the mentioned pump activity is very important for cell functioning. The other part of this article is dedicated to different regulation factors of smooth muscle plasma membrane Ca2+-pump activity: endogenous and exogenous, biotic and abiotic factors. Special attention is given to literature data and own results about design and the search of selective plasma membrane Ca2+-pump inhibitor which would allow examining its functioning in smooth muscle cells more meticulously.
Mg(2+),ATP-dependent plasma membrane calcium pump of smooth muscle cells. I. Structural organization and properties
T. O. Veklich, Iu. Iu. Mazur, S. O. Kosterin
Palladin Institue of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: veklich@biochem.kiev.ua; yuliya.vorona@gmail.com
Tight control of cytoplasm Ca2+ concentration is essential in cell functioning. Changing of Са2+ concentration is thorough in smooth muscle cells, because it determines relaxation/constraint process. One of key proteins which control Са2+ concentration in cytoplasm is Mg2+,ATP-dependent plasma membrane calcium pump. Thus, it is important to find compoumds which allowed one to change Mg2+,ATP-dependent plasma membrane calcium pump activity, as long as this topic is of current interest in biochemical research which regards energy and pharmacomechanical coupling mechanism of muscle excitation and contraction. In this article we generalized literatute and own data about properties of smooth muscle cell plasma membrane Ca2+– pump. Stuctural oganization, kinetical properties and molecular biology are considered.