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Journal archive > 2007 > N 3 May-June

COMPARATIVE RESEARCH OF CALIXARENS INFLUENCE ON Nа++-АТРase ACTIVITY
IN PLASMA MEMBRANE OF CONTRACTILE AND MOBILE CELLS

Т. O. Veklich1, N. S. Kocheshkova2, R. V. Rodik3, V. I. Boyko3, Z. D. Vorobets2, S. O. Kosterin1

1Palladin Institute of Biochemistry National Academy of Sciences of Ukraine, Kyiv;
2Danylo Galytsky Lviv Medical University, Ukraine;
3Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.1; This email address is being protected from spambots. You need JavaScript enabled to view it.2; This email address is being protected from spambots. You need JavaScript enabled to view it.3

The paper is devoted to comparative analysis of the influence of a new class of macrocyclic compounds – calixarens on enzymatic activity of two ATP-hydrolase systems localized in the plasmatic membrane of contractile (myocytes of the uterus) and mobile (spermatozoids) cells?– Na+,K+-ATP­ase and basal Mg2+-АТРase. The experiments performed on plasmatic membrane suspensions of myometrium and spermatozoids treated with detergent the authors studied the influence of calixarens C-97, C-99, C-107 (identified by the codes), functionalized with fragments of alpha-hydroxyphosphonic, alpha-aminophosphonic and methyl­enbisphosphonic acids accordingly, on enzymatic activity. The results have shown that C-97 and C-107 calixarenphosphonic acids in 100 µM concentration (97–99%) inhibit Na+,K+-ATPase activity in both cases almost completely. C-99 (100?µM) calixaren appeared to be less effective with regard of its influence on the enzymatic systems under study: in the case of plasmatic membranes of myometrium suspension the activity of Na+,K+-АТРase was decreased by 84–88%, and in the case of spermatozoids suspension?– just by 15–20% of the control. All the studied calixarens (for both objects) in the maximal concentration (100 µM) practically did not influence the activity of basal Mg2+-ATPase. The calixarens inhibited the enzymatic activity of Na+,K+-ATPase more effectively than ouabain: in the first case the value of apparent inhibition constant I0,5 was 25–100 nM, and in the second case – 20–100 µM. The inhibition influence of calixarens on Na+,K+-AТРase activity is characterized by the phenomenon of negative cooperativity (Hill’s coefficient nH < 1); the influence of ouabain in the case of plasmatic membranes of myometrium suspension is also characterized by negative cooperativity (nH?< 1), and in case of spermatozoids suspension?– by positive cooperativity (nH > 1). The above results show that the studied calixarens are effective inhibitors of Na+,K+-ATPase plasmatic membrane of contractive and mobile cells (C-97, C-99, C-107 calixarens in case of myocytes of uterus, and C-97, C-107 calixarens in case of spermatozoids).

Key words: Na+,K+-ATPase, Mg2+-ATPase, plasma membrane, retractiveness (mobility), myometrium, smooth muscle cells, spermatozoids, ouabain, calixarens.

The original article in Ukrainian is available for download in PDF format.

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