title: Interconversion of cyclic nucleotide-activated and cyclic nucleotide-independent forms of a protein kinase from beef heart.
abstract: A protein kinase activated by cyclic nucleotides was purified from beef heart. Upon exposure to adenosine 3':5'-cyclic monophosphate (cyclic AMP) during gel filtration on Sephadex G-200, the protein kinase dissociated into a cyclic nucleotide-independent protein kinase and a cyclic nucleotide-binding protein. A similar or identical cyclic nucleotide-independent protein kinase could be obtained in highly purified form by clution from a DEAE-cellulose column with 10(-6) M cyclic AMP; the cyclic AMP-binding protein was apparently retained by the resin. The addition of cyclic nucleotide-binding protein to cyclic nucleotide-independent protein kinase resulted in the reappearance of cyclic nucleotide-dependent protein kinase, which could be isolated by filtration on Sephadex G-200 in the absence of cyclic AMP. These results confirm and extend previous suggestions that cyclic nucleotides activate protein kinases by dissociating them from inhibitory, cyclic nucleotide-binding proteins.
mesh_terms: D000227:Adenine Nucleotides / Q000494:pharmacology*; D000818:Animals; D001669:Biochemical Phenomena; D001671:Biochemistry; D002417:Cattle; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D000242:Cyclic AMP / Q000494:pharmacology; D004789:Enzyme Activation; D009206:Myocardium / Q000032:analysis; D010759:Phosphorus Isotopes; D010770:Phosphotransferases / Q000302:isolation & purification; D011485:Protein Binding; D014316:Tritium
chemical_list: D000227:Adenine Nucleotides; D010759:Phosphorus Isotopes; D014316:Tritium; D000242:Cyclic AMP; D010770:Phosphotransferases