Calcium--calmodulin-dependent activation of porcine liver phosphorylase kinase.
Porcine liver phosphorylase kinase was activated about 1.5-fold by calmodulin in a calcium-dependent manner. Half-maximal stimulation was observed at about 80 nM calmodulin and the activation was almost pH-independent. The specific binding of porcine liver phosphorylase kinase to calmodulin--Sepharose affinity column exhibited an absolute dependence upon the presence of calcium. The physiological role of the calmodulin-dependent activation for liver phosphorylase kinase is discussed.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism*; D002846:Chromatography, Affinity; D004789:Enzyme Activation; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000201:enzymology*; D010764:Phosphorylase Kinase / Q000378:metabolism*; D011817:Rabbits; D013552:Swine
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D010764:Phosphorylase Kinase; D002118:Calcium