Analysis Note

Protein determined by biuret.

Application

Protein Kinase A from bovine heart has been used to determine its activity using a molecular beacon probe. It has also been used to study the interaction of staurosporine with the ATP-binding site of kinases.

Protein Kinase A from bovine heart has been used to inhibit the phosphorylation of myosin.

Biochem/physiol Actions

Many 3′,5′-cyclic AMP dependent protein kinases have been reported. Structural studies (Traugh, J.A., et al., Meth. Enzymol., 38, 290 [1974]) show the presence of at least two subunits, the regulatory subunit and the catalytic subunit. When both units are linked together, the catalytic activity is inhibited. However, when the cyclic-AMP binds to the regulatory subunit, the catalytic subunit is released and can then catalyze the transfer of phosphate from ATP to various proteins.

Protein Kinase A (PKA) inhibits hormone-sensitive lipase translocation from cytosol to storage droplets and blocks lipolysis. It regulates apoptosis, mitochondrial respiration and ATP synthesis. PKA is modulated by protease calpain.

General description

Protein Kinase A (PKA) is a serine/threonine kinase, which exists as a tetrameric holoenzyme.

Packaging

10 mg in poly bottle

Package size based on protein content

1, 5 mg in glass bottle

Physical form

Crude lyophilized powder containing EDTA and potassium phosphate, pH 7.5.

Preparation Note

Fractionated essentially by procedure of Gilman, A., Proc. Natl. Acad. Sci. USA, 67, 305 (1970).

Unit Definition

One unit will transfer 1.0 picomole phosphate from ATP to hydrolyzed and partially dephosphorylated casein per minute at pH 6.5 at 30°C in the presence of cyclic AMP, determined by measuring the production of ADP.