Novel bovine heart calmodulin-dependent protein kinase which phosphorylates a high molecular weight calmodulin-binding protein.
A novel calmodulin-dependent protein kinase has been isolated from bovine cardiac muscle by successive chromatography on DEAE-Sepharose 6B, Calmodulin-Sepharose 4B affinity and Sepharose 6B chromatography columns. The protein kinase was shown by gel filtration chromatography to have a molecular mass of 36,000 daltons. The highly purified protein kinase stoichiometrically phosphorylated the high molecular weight calmodulin-binding protein from cardiac muscle [Sharma RK (1990) J Biol Chem 265, 1152-1157] in a Ca2+/calmodulin-dependent manner. The phosphorylation resulted in the maximal incorporation of 1 mol of phosphate/mol of the high molecular weight calmodulin-binding protein. Other Ca2+/calmodulin-dependent protein kinases failed to phosphorylate the high molecular weight calmodulin-binding protein. The distinct substrate specificity of this protein kinase indicates that it is not related to the known calmodulin-dependent protein kinases and therefore constitutes a novel protein kinase.
Barnes
J A
JA
Department of Pathology, University of Saskatchewan, Royal University Hospital, Saskatoon, Canada.
King
M J
MJ
Kalra
J
J
Sharma
R K
RK
D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002148:Calmodulin-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D009206:Myocardium / Q000201:enzymology*; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity
D002148:Calmodulin-Binding Proteins; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases