In vitro enzymatic assays for Ser/Thr-selective protein kinases

Medium and high throughput methods for measuring the activities of Ser/Thr-selective protein kinases are described. These methods utilize radiochemical detection, fluorescence polarization, and ultraviolet spectroscopy to monitor transfer of the gamma-phosphoryl group of ATP to protein or peptide substrates. These assays have utility in characterizing protein kinase inhibitors and in mechanistic studies.