Affinity assays for decrypting protein targets of unknown function

The application of label-independent biophysical assays (affinity assays) to carefully selected libraries of biochemicals, natural products and known bioactive molecules generates a powerful tool to identify ligands indicative of protein function. Detection of ligand binding does not require the measurement of enzyme activity, thus every cofactor, ion, reactant or product might be identified separately. One such assay, ThermoFluor ®, monitors ligand perturbation of protein thermostability. In conjunction with a functional probe library (FPL), this assay has been used to decrypt the function of orphan proteins. Steve Gullans – RxGen Inc., New Haven, CT, USA Robert Zivin – Johnson and Johnson, New Brunswick, NJ, USA