Calcineurin SubstRate

The 19-peptide DLDVPIPGRFDRRVSVAAE is a fragment of the RII subunit of the cAMP-dependent protein kinase. It is successfully used in a nonradioactive assay in which both phosphorylation by protein kinase and dephosphorylation by protein phosphatase 2B (calcineurin) are monitored by the simultaneous quantitative determination of phosphorylated and non-phosphorylated peptide using HPLC on an RP18 column with UV detection. This method allows the measurement of enzyme kinetics as well as the characterization of novel inhibitors.