The importance of arginyl residues for phosphorylation of rat liver cell sap proteins.

Arginyl residues in phosvitin, histone and cell sap protein were blocked by 1,2-cyclohexanedione, resulting in markedly impaired phosphorylation of histone and cell sap. Interestingly, the phosphate incorporation into phosvitin was not changed by this treatment. Intact arginyl residues in the protein kinase substrates seemed to be essential for more than half of the cell sap phosphorylation at 5 mM ATP. Furthermore both phosvitin kinase and histone kinase activities in cell sap were inhibited by arginyl residue blockade, indicating that these enzymes had functional arginyl residues.