PNA-tagged peptide microarrays for ratiometric activity detection of cellular protein kinases

Peptide microarrays can be used to measure the activity of multiple protein kinases (PKs), which can be used to elucidate kinomics for drug discovery and diagnosis. Here we demonstrated a new microarray for ratiometric detection of the activity of PKs using peptide nucleic acid (PNA)-tagged peptides labeled with two different fluorophores, Cy3 and Cy5. We successfully detected cellular PK activities based on ratiometry, and applied the system for evaluation of an inhibitory drug.