[Ca2+ (calmodulin)-dependent phosphorylation of plasma membranes of pig myometrium].
The high-purified vesicles of pig myometrium sarcolemma closed, mainly, so that the cytoplasmatic side is outside possess the Ca2+ (calmodulin)-dependent protein kinase activity. The initial rate of the endogenic phosphorylation without exogenic calmodulin is 6.3 and with its presence--10.7 pmol of 32Pi 1 min per 1 mg of protein. Km for ATP is equal to 164 microM, and Vmax--0.27 nmol of 32Pi 1 min per 1 mg of protein. Exogenic calmodulin increases the affinity to ATP (50 microM), Vmax being unchanged. Under optimal concentrations of calmodulin (10(-7)-10(-6) M) and 10(-4) M Ca2+ the protein kinase activity is 0.132 nmol of 32Pi min per 1 mg of protein. Electrophoresis in DS-PAAG has shown that membrane proteins with molecular weight of 105, 58, 25, 12 and 2 kDa are basic substrates of Ca2+ (calmodulin)-dependent phosphorylation. Trifluoperazine++ in the concentration of 40 microM inhibits phosphorylation of all five proteins. Ca2+ (calmodulin)-dependent phosphorylation is supposed to be a regulator of Ca2+-transport processes of sarcolemma.
Prishchepa
L A
LA
Kondratiuk
T P
TP
Kurskiĭ
M D
MD
D000818:Animals; D002147:Calmodulin / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology; D005260:Female; D007700:Kinetics; D009215:Myometrium / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D013552:Swine
D002147:Calmodulin; D011494:Protein Kinases
Ca2+(Kal'modulin)-zavisimoe fosforilirovanie plazmaticheskikh memran miometriia svin'i.