[Effect of spermine on activity of purified Ca2+, Mg2+-ATPase from plasma membranes of myometrium cells].
Effect of endogenous polyamine spermine, a relaxant of smooth muscle, on the activity of myometrium cell plasma membrane Ca2+, Mg(2+)-ATPase was studied. It was observed a tendency to activation of enzyme at the spermine concentrations 0.1-0.5 mM, the increase of the polyamine concentrations up to 10 mM inhibited. ATPase by 80% (I50 = 5.5 +/- 0.3 mM). Spermine inhibited enzyme decreasing its turnover rate and affinity for Ca2+. The ATPase affinity for Mg2+ increased in the presence of spermine. It was revealed, that the inhibitory effect of spermine is changed by the stimulatory effect under the increase of Ca2+ concentration (up to 2.6 microM), that correlates with the relaxing effect of this polyamine on the smooth muscle.
Slinchenko
N M
NM
Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv. slinchenko@biochem.kiev.ua
Chernysh
I H
IH
Kosterin
S O
SO
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors*; D002384:Catalysis; D002462:Cell Membrane / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D009215:Myometrium / Q000166:cytology / Q000201:enzymology*; D013096:Spermine / Q000494:pharmacology*; D013552:Swine
D004791:Enzyme Inhibitors; D013096:Spermine; D017301:Ca(2+) Mg(2+)-ATPase