Metal interaction chromatography amino acid specificity

Immobilized metal-affinity chromatography (IMAC) is also known as metal-chelate affinity chromatography (MCAC). This method was first proposed by Porath et al. in 1975 [63] and is based on the specific interactions between immobilized metal ions and amino acid residues, such as histidine, fiyptophan, and cysteine in proteins or peptides [63]. IMAC has become an important tool for the detection and purification of metalloproteins, histidine-tagged proteins, and phosphorylated proteins. Areas in which this method is now used include proteomics [64—66], work with recombinant proteins [67—69], and disease diagnosis [70,71]. 

Metal-chelate affinity chromatography was introduced as a specific method for fractionation of proteins by Porath et al., in 1975. The principle of this type of chromatographic method is that certain amino acid residues, such as histidine, cysteine, lysine, tryptophan, aspartic acid, glutamic acid, or phosphorylated amino acids, which are accessible on the protein surface, can interact through non-bonding lone-pair electron coordination with some metal ions. Metal cations Cu, Ni, ... 

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