A continuous luminescence assay for monitoring kinase activity: signalling the ADP/ATP ratio using a discrete europium complex.

We report the application of a stable cationic europium complex [Eu.1]+ in a continuous-read luminescence assay for kinase activity. [Eu.1]+ binds reversibly to ATP and ADP in water, at neutral pH, in the presence of Mg2+ ions, providing distinctive luminescence responses that permits the kinase-catalysed conversion of ATP to ADP to be monitored in real-time.