GST Tag Protein Purification

GST tag purification kits and reagents are tailored to reliably collect recombinant proteins with the glutathione S-transferase tag. GST specifically binds its substrate, the tripeptide glutathione, in neutral physiological conditions. Thus, glutathione immobilized to a solid support, such as agarose or a magnetic bead, readily purifies proteins bound to GST. The tag is 220 amino acids long and is roughly 26 kDa in mass, but can be enzymatically removed with a protease if a cleavage site is available. In addition to the desired scale or throughput of the purification, also consider the expression system when choosing a kit to purify GST-tagged proteins.