Recombinant human cAMP-dependent protein kinase: PKA, holo type I alpha, 25 µg

Background: cAMP-dependent protein kinase (PKA) is an ubiquitous serine/theonine protein kinase present in a variety of tissues (e.g. brain, skeletal muscle, heart). The intracellular cAMP level regulates cellular responses by altering the interaction between the catatytic C and regulatory R subunits of PKA. The inactive tetrameric PKA holoenzyme R2C2 is activated when cAMP binds to R2, which dissociates the tetramer to R2*cAMP4 and two active catalytic subunits. Free catalytic subunits of PKA can phosphorylate a wide variety of intracellular target proteins. In response to hormone-induced high cAMP levels, PKA phosphorylates glycogen synthetase (inhibition of the enzyme activity) and phosphorylase kinase to block glycogen synthesis.

The inactive holoenzyme consists of one dimeric regulatory subunit type Iα (monomer of 43 kD) and two monomeric catalytic subunits. Holo enzyme can be activated by adding the second messenger cAMP (activation constant about 100nM) releasing two monomeric catalytic subunits. The product is suitable for analysing PKA type I agonists (cAMP analogs) or antagonists. 

Theoretical MW: 168 kDA
Expression system: E. coli
Storage buffer: 20 mM MOPS (pH 7.0), 5 mM MgCl2, 100 µM ATP, 150 mM NaCl, 50% glycerol
Purity:  >95% (SDS-PAGE)
Shipping conditions: Dry ice
Protein concentration:  0.55 mg/ml (Bradford method using BSA as standard protein)

Specific Activity : The specific activity of PKA catalytic subunit upon activation of the inactive PKA holoenzyme, type Iα, is >15,000,000 U/mg whereby one unit is defined as the amount of catalytic subunit required to incorporate 1 pmol of phosphate into the substrate peptide Kemptide (LRRASLG) in one minute at 30 °C.

Ordering information: shipped on dry ice

Entrez Gene ID: 18747/5573
UniProtKB:  P05132/P10644

Product specific literature references:

Otten AD, McKnight GS (1989) "Overexpression of the type II regulatory subunit of the cAMP-dependent protein kinase eliminates the type I holoenzyme in mouse cells" J. Biol. Chem. 264(34):20255-60

Product Citations:

Wolter S, Golombek M, Seifert R. (2011) "Differential activation of cAMP- and cGMP-dependent protein kinases by cyclic purine and pyrimidine nucleotides."Biochem Biophys Res Commun. 2011 Dec 2;415(4):563-6.

Brennan JP, Bardswell SC, Burgoyne JR, Fuller W, Schröder E, Wait R, Begum S, Kentish JC, Eaton P. (2006) "Oxidant-induced activation of type I protein kinase A is mediated by RI subunit interprotein disulfide bond formation."J Biol Chem. 2006 Aug 4;281(31):21827-36.

Courilleau D, Bisserier M, Jullian JC, Lucas A, Bouyssou P, Fischmeister R, Blondeau JP, Lezoualc'h F. (2012) "Identification of a tetrahydroquinoline analog as a pharmacological inhibitor of the cAMP-binding protein Epac." J Biol Chem. 2012 Dec 28;287(53):44192-202.