Description
Kemptide, phosphate acceptor, is shown to be a basic serine-containing heptapeptide corresponding to a sequence from pig liver pyruvate kinase. This synthetic peptide is a substrate of PKA (cyclic AMP-dependent protein kinase) and is phosphorylated and activated after microinjection into Xenopus oocytes. Exposure of Kemptide to insulin has demonstrated an increase in activation of this agent, which can be inhibited by the catalytic subunit of phosphatase 2A