Identification and purification of target protein using affinity resin bearing a photo-labile linker.

This Letter presents an effective method for the identification of target proteins of bioactive compounds such as drugs, natural products, and intrinsic ligands, using an affinity resin. The application of a photo-labile linker to an affinity resin enabled the selective elution of a target protein by irradiation for a short duration at 4 °C while leaving a large amount of non-specific binding protein on the resin. We have named this method the 'STEAP' method (selective target elution from affinity resins with photo-labile linker). Only a target protein that can bind the bioactive compound, the so-called 'active' protein, is eluted by the selective cleavage of the linker between the solid matrix and the target compound, and therefore, it is worth considering the potential of this method for the hyper-purification of proteins.