Fast screening of ligand-protein interactions based on ligand-induced protein stabilization of gold nanoparticles.

High throughput screening of small molecular weight (LMW) ligands for protein and sensitive determination of ligand-induced protein stabilization is an important task in drug discovery and in protein structural and functional genomics studies. In this study, gold nanoparticles (AuNPs) and their aggregation property are used to develop a rapid and less equipment intensive assay for screening the interactions between LMW ligands and transcription factors (TFs) and human serum albumin. The assay is based on the fact that the aggregation/discpersion status of AuNPs is very sensitive to the conformation of surrounding proteins, and when a LMW ligand binds to the proteins, it can enhance proteins’ salt and thermal stability, and therefore the protective effect on AuNPs from aggregation. Two TFs, i.e. FoxA1 (Forkhead box A1) and AP-2γ (activating enhancer binding protein 2 gamma), and 14 compounds from an NCI compounds library and human serum albumin (HSA) and three known ligands (ibuprofen, warfarin, and phenyt...