[Ca2+-calmodulin-dependent phosphorylation and passive transport of Ca2+ in the myocardial sarcolemma].
Highly purified vesicles of rabbit myocardium sarcolemma with predominant inside-out orientation possess the Ca2+-calmodulin-dependent protein kinase activity. At optimal concentrations of calmodulin (0.5 microM) and Ca2+ (0.1 mM), the activity of protein kinase is 0.21 nmol 32P X min X mg of protein. The Km(app) value for ATP is 3.0 X 10(-6) M, V = 0.27 nmol 32P X mg of protein X min. Endogenous Ca2+-calmodulin-dependent protein kinase phosphorylates four protein substrates in sarcolemmal vesicles (Mr = 145, 22, 11.5, and 6-8 KD). Studies with passive efflux of Ca2+ from the SL vesicles showed that the Ca2+-calmodulin-dependent phosphorylation of protein components of sarcolemma inhibits this reaction.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D017301:Ca(2+) Mg(2+)-ATPase; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011817:Rabbits; D012508:Sarcolemma / Q000201:enzymology / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D002147:Calmodulin; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D017301:Ca(2+) Mg(2+)-ATPase; D000262:Adenylyl Cyclases; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium
Ca2+-kal'modulinzavisimoe fosforilirovanie i passivnyĭ transport Ca2+ sarkolemmoĭ miokarda.