Adenosine 3′ : 5′-Monophosphate-dependent Protein Kinase from Yeast

Abstract Adenosine 3' : 5'-monophosphate (cyclic AMP)-dependent protein kinase which catalyzes the phosphorylation of histone and protamine is purified about 100-fold from the soluble fraction of bakers' yeast by streptomycin treatment, ammonium sulfate fractionation, followed by DEAE-cellulose column chromatography and isoelectrofocusing electrophoresis. A divalent cation, Mg2+, Mn2+, or Co2+, is needed for the enzyme activity. The apparent Ka value for cyclic AMP is about 2 x 10-8m. The mode of action of the cyclic nucleotide is essentially similar to that described for mammalian enzymes. Comparative studies have revealed that yeast and rat liver cyclic AMP-dependent protein kinases exhibit closely similar but not exactly identical kinetic and catalytic properties. Nevertheless, the catalytic and regulatory units from yeast and liver enzymes are crosswise reactive, and recombination of these units of the heterologous sources produces a hybrid cyclic AMP-dependent protein kinase.