Phosphorylation and inactivation of brain glycogen synthase by a multifunctional calmodulin-dependent protein kinase.
Glycogen synthase was partially purified from canine brain to about 70% purity. The purified enzyme showed differences from the properties of the skeletal muscle enzyme with respect to molecular weights of the holoenzyme and subunit and phosphopeptide mapping. The multifunctional calmodulin-dependent protein kinase from the brain phosphorylated brain glycogen synthase with concomitant inactivation of the enzyme. Although about 1.3 mol of phosphate/mol subunit was maximally incorporated into glycogen synthase, 0.4 mol of phosphate/mol subunit was sufficient for the maximal inactivation of the enzyme. The results indicate that brain glycogen synthase is regulated in a calmodulin-dependent manner similarly to the skeletal muscle enzyme, but that the brain enzyme is different from the skeletal muscle enzyme.
D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology*; D002147:Calmodulin / Q000494:pharmacology*; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D006006:Glycogen Synthase / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*
D002147:Calmodulin; D006006:Glycogen Synthase; D011494:Protein Kinases