Immobilised metal ion affinity

Another very important form of affinity chromatography is immobilised metal ion affinity chromatography (IMAC) (Kagedal 1989 Yip and Hutchens 1996). This... 

Willoughby N.A., Kirschner T., Smith M.P., Hjorth R. and Titchener-Hooker N.J. 1999. Immobilised metal ion affinity chromatography purification of alcohol dehydrogenase from baker s yeast using an expanded bed adsorption system, J. Chromatogr. A, 40, 195-204. 

Chaouk H. and Hearn M.T. 1999. New ligand, N-2-pyridylmethyl aminoacetate, for use in the immobilised metal ion affinity chromatographic separation of proteins, J. Chromatogr. A, 852, 105. 

Phosphoproteins (various). Purified by adsorbing onto an iminodiacetic acid substituted agarose column to which was bound ferric ions. This chelate complex acted as a selective immobilised metal affinity adsorbent for phosphoproteins. [Muszyfiska et al. Biochemistry 25 6850 1986.]... 

Cu(II) has been shown to be bound by two cysteines [32]. The main limitation of the use of cysteine or glutathione for detecting metal ions is the thiol side chain which having a high affinity for soft metals is being employed to immobilise the peptide and hence is not available for coordination with the metal ion. 

Figure 2.26 Immobilised Metal Affinity Chromatography (IMAC). Metal ions (for instance, Ni + ions) are gel-immobilized by chelation to groups covalently attached to the solid support. Histidine (His) residues in proteins (or part of a His-tag) have a high affinity for the immobilized ion. Elution is typically carried out by using a competitively high concentration of imidazole.

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