Protein phosphatase 2A (PP2A) is a specific protamine-kinase-inactivating phosphatase, one common physiological form of which is PP2A₂.

Protein phosphatase 2A₂ has been used in a study to investigate two heat-stable protein inhibitors. It has also been used in a study to describe the purification and properties of a protamine kinase from bovine kidney microsomes.

Protein Phosphatase 2A2 from bovine kidney was shown to be a unique inhibitor of protamine kinase while other phosphatases in the same family including PP1, PP2B, PP2C did not show any inhibition.

Solution of 1 μg per vial in 50 μl of 50 mM Tris-HCl, pH 7.0, containing 14 mM β-Mercaptoethanol, 1mM benzamidine, 0.1 mM PMSF, 1mM EDTA, and 50% glycerol.

One unit will release 1 nanomole of inorganic phosphate from (32)P-labeled phosphorylase per minute at pH 7.0 at 30 deg C.