Glutathione S-transferase pull-down assays using dehydrated immobilized glutathione resin

We have developed an affinity-precipitation technique to facilitate conducting glutathione S-transferase (GST) pull-down assays. The dehydrated immobilized glutathione resin format, when combined with microcentrifuge spin columns, is a powerful tool that enables the simultaneous performance of resin hydration, the binding of the GST fusion protein, and the pull-down step with the appropriate protein partner in a semihigh-throughput fashion (multiple samples processed at the same time). The entire assay process is shortened and recovery is enhanced when coupled with a spin-column format, providing a convenient way to study protein-protein interactions. We successfully tested the resin format/technique in three common pull-down applications utilizing radiolabeled, overexpressed, and activated endogenous interacting protein partners.