Separation of calmodulin from calcium-activated protein kinase using calcium-dependent hydrophobic interaction chromatography.
To determine whether a Ca2+-activated protein kinase is regulated by calmodulin, it is necessary to separate it from endogenous calmodulin and from protein kinase activity that is not calcium dependent. We describe here a procedure for achieving these goals using Ca2+-dependent hydrophobic interaction chromatography on phenyl Sepharose in combination with a pH change. The procedure is based on the observation that while calmodulin solubilized from apple fruit membranes binds to phenyl Sepharose in a Ca2+-dependent fashion at both pH 7.0 and 8.5, Ca2+-activated protein kinase from the same source only shows a Ca2+-dependent interaction above pH 7.5. The implications of this finding for the regulation of this Ca2+-activated protein kinase are briefly discussed.
Battey
N H
NH
Institute of Horticultural Research, Maidstone, Kent, United Kingdom.
Venis
M A
MA
D002118:Calcium / Q000494:pharmacology*; D002147:Calmodulin / Q000302:isolation & purification*; D002845:Chromatography / Q000379:methods; D008565:Membrane Proteins / Q000302:isolation & purification; D010940:Plant Proteins / Q000032:analysis; D011485:Protein Binding; D011494:Protein Kinases / Q000302:isolation & purification*; D012995:Solubility; D017871:Calcium-Calmodulin-Dependent Protein Kinases
D002118:Calcium; D002147:Calmodulin; D008565:Membrane Proteins; D010940:Plant Proteins; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases