Purification and characterization of active fragment of Ca2+/calmodulin-dependent protein kinase II from the post-synaptic density in the rat forebrain.
Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) of the post-synaptic density (PSD) was solubilized and activated 4- to 5-fold by limited alpha-chymotrypsin digestion with prior autophosphorylation of the kinase. The enzyme was also activated by trypsin and mu-calpain, a Ca(2+)-dependent protease. The active catalytic fragment was purified to homogeneity using gel filtration and ion exchange chromatography. The purified active fragment was completely Ca2+/calmodulin-independent and exists as a monomer. Kinetic studies with the purified fragment revealed similar Km values for ATP and synthetic peptide substrate, and an about 8-fold increment in Vmax, compared with native PSD CaM kinase II.
Yoshimura
Y
Y
Department of Biochemistry, University of Tokushima.
Nomura
T
T
Yamauchi
T
T
D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000302:isolation & purification* / Q000378:metabolism; D002384:Catalysis; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004789:Enzyme Activation; D006868:Hydrolysis; D007700:Kinetics; D010766:Phosphorylation; D016548:Prosencephalon / Q000201:enzymology*; D051381:Rats; D012995:Solubility; D013379:Substrate Specificity; D013569:Synapses / Q000201:enzymology*
D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases