Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.11.17 (CaMKII)
 4,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adenosine 3",5"-monophosphate (cAMP)-dependent ATPase (ATP phosphohydrolase, EC 3.6.1.3) activity of cAMP-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) from bovine heart is characterized. That the ATPase activity is intimately associated with the catalytic subunit of the enzyme is suggested by the following: (i) the similar dependences of ATPase and protein kinase activities on cAMP; (ii) the dissociation of ATPase activity from the holoenzyme on addition of cAMP and its co-elution with the catalytic subunit on gel filtration chromatography; (iii) the similarity of the relative effectiveness of divalent metal ions in ATPase and protein kinase catalysis; and (iv) the correspondence of kinetically determined Km(MgATP) and Ki(MgADP) values with thermodynamic dissociation constants determined by equilibrium dialysis. The hydrolysis of ATP is stimulated 10- to 20-fold by cAMP in the holoenzyme. The molar specific activity of the catalytic subunit ATPase is approximately 0.7 min-1 with Km(MgATP) = 5 muM. MgADP is a competitive inhibitor of the reaction with a Ki value of approximately muM. The order of the relative effectiveness of metal ions for both ATPase and peptide kinase activities is Mg2+ greater than Mn2+ greater than Ca2+. A possible interpretation of these observations is that the role that the metal ion plays is more directly manifested in bond-breaking than in bond-forming.
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PMID:Cyclic AMP-dependent ATPase activity of bovine heart protein kinase. 21 18

Sarcomplasmic reticulum from rabbit fast skeletal muscle contains intrinsic protein kinase activity (ATP:protein phosphotransferase, EC 2.7.1.37) and a substrate. The protein kinase activity was Mg2+ dependent and could also phosphorylate exogenous protein substrates. Autophosphorylation of sarcoplasmic reticulum vesicles was not stimulated by cyclic AMP, neither was it inhibited by the heat-stable protein kinase inhibitor protein. The phosphorylated membranes had the characteristics of a protein with a phosphoester bond. An average of 73 pmol Pi/mg protein were incorporated in 10 min at 30 degrees C. Addition of exogenous cyclic AMP-dependent protein kinase increased the endogenous level of phosphorylation by 25-100%. Sarcoplasmic reticulum membrane phosphorylation, mediated by either endogenous cyclic AMP-independent or exogenous cyclic AMP-dependent protein kinase, occurred on a 100 000 dalton protein and both enzyme activities resulted in enhanced calcium uptake and Ca2+-dependent ATPase (ATP phosphohydrolase, EC 3.6.1.3), in a manner similar to cardiac microsomal preparations. Regulation of Ca2+ transport in skeletal sarcoplasmic reticulum may be mediated by phosphorylation of a 100 000 dalton component of these membranes.
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PMID:Phosphorylation of a 100 000 dalton component and its relationship to calcium transport in sarcoplasmic reticulum from rabbit skeletal muscle. 624 11