Adenosine 3':5' monophosphate regulated phosphorylation of erythrocyte membrane proteins. Separation of membrane associated cyclic adenosine 3':5' monophosphate dependent protein kinase from its endogenous substrates

摘要: An adenosine 3':5'-monophosphate (cyclic AMP)-binding protein in the human erythrocyte plasma membrane was isotopically labeled using a photoaffinity analog of cyclic AMP, N6-(ethyl 2-diazomalonyl) [3H]AMP. The AMP-binding site is located polypeptide chain having molecular weight 48,000. Cyclic and AMP-dependent kinase were solubilized with 0.5% Triton X-100 56 mM sodium borate, pH 8, but 32P-labeled phosphoproteins retained Triton-insoluble fraction, suggesting that membrane-associated binding not primary substrate for kinase. Triton-solubilized activities stimulated 15- 17-fold by degree association between catalytic anc components very similar both preparations. Fractionation characterization have shown III co-migrating minor are substrates sialoglycoproteins phosphorylated.