Calf‐Ovary Protein Kinases Dependent on Adenosine 3′: 5′‐Monophosphate

High resolving power and quantitative application of polyacrylamide‐gel electrophoresis at various pore sizes and electrofocusing provide resolution of a calf‐ovarian protein‐kinase system at an increased level of magnification, as well as optimal preparative routes. Three protein kinases dependent on adenosine 3′:5′‐monophosphate are distinguished by polyacrylamide gel electrophoresis in calf ovarian cytosol. These enzymes which are observed in the pH range 7.5–10.2, appear to be aggregates of a common subunit or monomer. The three kinases are, by the criteria of polyacrylamide gel electrophoresis, distinct from three adenosine‐3′:5′‐monophosphate‐binding proteins found in the calf ovarian system. Analysis by electrofocusing on polyacrylamide gel shows that conventionally purified preparations of the major kinase of cytosol contain an overwhelming majority of contaminant proteins.