[Ca2+-transporting properties of myometrial plasma cell membrane Ca2+, Mg2+-ATPase reconstituted in liposomes].
Purified myometrium cells plasma membrane Ca2+, Mg(2+)-ATPase was reconstitute in liposomes in functionally active state by the method of cholate dialysis: it showed ATP-hydrolase activity increased by 0.8 microM A23187 average 4 times and it showed Mg2+, ATP-dependent Ca(2+)-transporting activity. Reconstituted system transported Ca2+ at an initial rate of 114.4 +/- 16.3 nmol.min-1.mg-1 with the stoichiometry Ca2+: ATP = 1: (3.2-3.7). Calmodulin increased by 30% the initial rate of Ca(2+)-accumulation by the proteoliposomes with reconstituted Ca2+, Mg(2+)-ATPase; 0.1 mM orthovanadate decreased by 80% Ca(2+)-accumulation by this system. Ca2+, Mg(2+)-ATPase reconstituted in liposomes is just Ca(2+)-transporting ATPase of the plasma membrane. Obtained enzyme preparate can be utilised for study of the properties of this important energy-dependent Ca(2+)-transporting system of smooth muscle cell.
Slinchenko
N M
NM
A. V. Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv.kinet@biochem.kiev.ua
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D005260:Female; D017136:Ion Transport; D008081:Liposomes; D009215:Myometrium / Q000201:enzymology*
D008081:Liposomes; D000255:Adenosine Triphosphate; D017301:Ca(2+) Mg(2+)-ATPase; D002118:Calcium
Ca2+-transportuiuchi vlastyvosti rekonstruĭovanoï membrany klityn miometriia.