Characteristics of heart sarcolemmal calcium transport system and effect of protein kinase on sarcolemmal calcium accumulation.
Properties of the ATP-dependent calcium transport system of heart sarcolemma are presented. Calcium accumulation (with oxalate) in sarcolemma was increased due to cAMP-dependent protein kinase and phosphorylase b kinase. Protein kinase increased the Vmax of the sarcolemmal calcium accumulation without any detectable effect on the affinity for Ca2+. Both kinases failed to stimulate calcium binding. Protein kinase catalyzed phosphorylation of membrane proteins of molecular weights of 100,000, 25,000, and 14,000. Phosphorylase b kinase also catalyzed phosphorylation of these proteins. Protein kinase stimulated ATPase activity of sarcolemma. Sarcolemma contained endogenous protein kinase and protein phosphatase activities.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D000242:Cyclic AMP / Q000494:pharmacology; D004789:Enzyme Activation; D006352:Heart Ventricles / Q000378:metabolism; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010070:Oxalates / Q000494:pharmacology; D010764:Phosphorylase Kinase / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D012508:Sarcolemma / Q000187:drug effects / Q000378:metabolism*
D008565:Membrane Proteins; D010070:Oxalates; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D011494:Protein Kinases; D010764:Phosphorylase Kinase; D002118:Calcium