Synthetic Akt Substrate Peptide

Stable for 1 year in working aliquots at -20C. Avoid repeated freeze-thaw cycles.

The synthetic peptide RPRAATF can be used as a substrate for AKT/PKB in, in vitro, kinase assays. It is phosphorylated by AKT1/PKBa with a Km of 25 uM. Protein kinase B or Akt (PKB/Akt) is a serine/threonine kinase, which in mammals comprises three highly homologous members known as PKBa, PKBb, and PKBg (AKT3). AKT/PKB is activated in cells exposed to diverse stimuli such as hormones, growth factors, and extracellular matrix components. The activation mechanism remains to be fully characterised but occurs downstream of phosphoinositide 3-kinase (PI 3K). PI-3K generates phosphatidylinositol-3, 4, 5-trisphosphate (PIP(3)), lipid second messenger essential for the translocation of PKB/Akt to the plasma membrane where it is phosphorylated and activated by phosphoinositide-dependent kinase-1 (PDK-1) and possibly other kinases. PKB/Akt phosphorylates and regulates the function of many cellular proteins involved in processes that include metabolism, apoptosis, and proliferation. Recent evidence indicates that PKB/Akt is frequently constitutively active in many types of human cancer. Akt1 contains a region homologous to a pleckstrin domain found in multiple signaling molecules and is stimulated by a number of receptor tyrosine kinases, including receptors for IGF, NGF, PDGF, VEGF, angiotensin, and insulin, by the action of phosphatidylinositol 3-kinase (PI 3-kinase).

Reconstitution in 3 ml dd water results in a 400 uM solution recommended for AKT1/PKBalpha activity assays.