Lonza's PKLight protein kinase assay on the PHERAstar FS plate reader

Andrew Paine, Lee Walker Cambrex Bio Science (Lonza) 08/2005


Using the cAMP Dependant Protein Kinase (PKA) and Kemptide substrate as a model we have demonstrated the usefulness of using the Lonza kinase reagents to measure kinase activity and inhibition.

This method is very simple to develop and run and can potentially be applied to any ATP-dependent protein kinase and target substrate. We have proved the  assay to be robust with Z’ values greater than 0.8 exhibited and reproducible and sensitive enough to determine low potency inhibition. The assay can be easily miniaturised down to 384-well plate formats  with the potential to go beyond.

Protein kinases and their ability to phosphorylate proteins play key roles in the signal transduction pathways of many diseases such as cancer, arthritis and diabetes. The importance of protein kinases makes them common targets for many High Throughput Screening (HTS) departments within the pharmaceutical industry.


In contrast to current technologies, Lonza developed a non-radioactive, homogeneous, robust and simple assay for screening potentially all protein kinases in 96-, 384- and 1536-well format. This technology utilizes Luciferase bioluminescence to measure ATP consumption as a result of kinase phosphorylation of the target substrate. The assay can be easily optimized for each kinase/substrate pair to produce rapid, quality data suitable for IC50 determination of screen compounds.


The luminescence signal is detected using a luminometer such as the multifunctional BMG LABTECH PHERAstar® FS plate reader. In this application note we use the Ser/Thr Kinase, cAMP dependant protein kinase (PKA) to demonstrate the assay.

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