Immobilizedmetal affinity chromatography

Abstract

Immobilized-Metal Affinity Chromatography (IMAC) is a separation technique that uses covalently bound chelating compounds on solid chromatographic supports to entrap metal ions, which serve as affinity ligands for various proteins, making use of coordinative binding of some amino acid residues exposed on the surface. Development of IMAC technique was accelerated by the fast maturation of recombinant techniques and by the invention of an improved chelating ligand. IMAC had originally been developed as a group separation method for metallo- and histidine-containing proteins. Today, these features are made use of in proteome-wide studies where the reduction of the complexity of the system (the proteome) is indispensable for sensitive analyses of low-abundance proteins. The IMAC principle offers wide range of applications for research in general and for production of His-tagged proteins in particular. Its robustness and versatility are the reasons why IMAC has become one of the most broadly used chromatographic methods. Modifications in production procedures for both resin and ligand materials as well as optimized application protocols led to a significant improvement of IMAC performance.