Purification and Characterization of a Ca2+‐ and Calmodulin‐Dependent Protein Kinase from Rat Brain

Kohji Fukunaga, Hideyuki Yamamoto, Kazuo Matsui, Kenji Higashi, Eishichi Miyamoto

Research output: Contribution to journalArticle

144 Citations (Scopus)

Abstract

Abstract: A Ca2+‐ and calmodulin‐dependent protein kinase was purified from rat brain cytosol fraction to apparent homogeneity at approximately 800‐fold and with a 5% yield. The purified enzyme had a molecular weight of 640,000 as determined by gel filtration analysis on Sephacryl S‐300 and a sedimentation coefficient of 15.3 S by sucrose density gradient centrifugation, and resulted in a single protein band of MW 49,000 by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. These results suggest that the native enzyme has a large molecular weight and consists of 11 to 14 identical subunits. The purified enzyme exhibited Km values of 109 and 30 μM for ATP and chicken gizzard myosin light chain, respectively, and Ka values of 12 nM and 1.9 μM for brain calmodulin and Ca2+, respectively. In addition to myosin light chain, myelin basic protein, casein, arginine‐rich histone, microtubule protein, and synaptosomal proteins were phosphorylated by the enzyme in a Ca2+‐ and calmodulin‐dependent manner. The purified enzyme was phosphorylated without the addition of the catalytic subunit of cyclic AMP‐dependent protein kinase. Our findings indicate that there is a multifunctional Ca2+‐ and calmodulin‐dependent protein kinase in the brain and that this enzyme may regulate the reactions of various endogenous proteins.

Original languageEnglish
Pages (from-to)1607-1617
Number of pages11
JournalJournal of Neurochemistry
Volume39
Issue number6
DOIs
Publication statusPublished - 1982 Dec
Externally publishedYes

Keywords

  • Brain cytosol fraction
  • Ca‐ and calmodulin‐dependent protein kinase
  • Microtubule
  • Synaptosomal fraction

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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