Description
Protein Kinase A (PKA) catalyzes the transfer of the terminal phosphate of ATP to threonine or serine residues in a variety of protein substrates. The enzyme is composed of two subunit types: a catalytic subunit and a regulatory subunit. In the absence of cAMP, the two subunits are bound to each other and no catalysis can take place. In the presence of cAMP, the regulatory subunit binds cAMP, thus releasing the catalytic subunit.
Form
Lyophilized from a solution containing: 5–10% potassium phosphate buffer, pH 7.5, 5–10% EDTA, and 80–90% protein (biuret assay).
Enzyme Commission Number
EC 2.7.11.11
Activity
>0.4 units/μg protein
Unit Definition
One unit will transfer 1.0 picomole phosphate from γ-32P-ATP to hydrolyzed and partially dephosphorylated casein per min at pH 6.5 at 30 °C in the presence of cyclic AMP.
Storage
Store the product at –20 °C. The dry solid is shipped at ambient temperature with minimal loss in activity. When stored at –20 °C with desiccant, the protein will lose <10% activity per year.
Preparation Instructions
It is recommended that a 1 mg/ml or greater stock solution solution be prepared in water or 0.5 mM citrate buffer, pH 6.5, and stored in aliquots at –20 °C.
Synonyms
Protein kinase A; PKA; Protein Kinase; 3',5'-cyclic-AMP-dependent Protein Kinase