| Binding, the non-covalent interaction between biomolecules or the interaction between ligands and receptors can either enhance or inhibit biological functions. More and more ligands have been discovered and some of them have been developed as therapeutic agents. Besides, several protein tags and their corresponding ligands, such as GST and glutathione, have been utilized for affinity purification, immobilization of tagged proteins, or the labeling of the tagged proteins with fluorophore. While the demand of exploring novel therapeutic targets, therapeutic agents, and protein tagging systems is increasing, instead of screening either OBOC or PHD libraries against a single target, my study is focusing on the development of a approach of screening PHD libraries against OBOC small molecule library. This novel multiplex screening method is employed in two applications in my studies. One is to screen the OBOC small molecule library against phage display human tumor proteome library to identify novel drugable targets and their corresponding therapeutics at the same time. A small molecule inhibitor against Human translation initiation factor 5B, EIF5B, was discovered and can be a valuable tool to dissect the effect of translation regulation. The other one is to screen the same OBOC small molecule library against a phage display random peptide library. A peptide-small molecule binding partner was discovered through the screening and affinity optimization. The peptide can be used to tag the protein of interest and the small molecule can be used to probe the tagged protein. As more peptide-small molecule binding pairs will be discovered through this novel screening strategy, these binding pairs can be utilized to develop multi-color probing system to visualize in vivo protein colocalization in cells. |
