Metal ion affinity

An artificial metalloenzyme (26) was designed by Breslow et al. 24). It was the first example of a complete artificial enzyme, having a substrate binding cyclodextrin cavity and a Ni2+ ion-chelated nucleophilic group for catalysis. Metalloenzyme (26) behaves a real catalyst, exhibiting turnover, and enhances the rate of hydrolysis of p-nitrophenyl acetate more than 103 fold. The catalytic group of 26 is a -Ni2+ complex which itself is active toward the substrate 1, but not toward such a substrate having no metal ion affinity at a low catalyst concentration. It is appearent that the metal ion in 26 activates the oximate anion by chelation, but not the substrate directly as believed in carboxypeptidase. 

Li, S. and Dass, C., Iron(III)-Immobilized Metal Ion Affinity Chromatography and Mass Spectrometry for the Purification and Characterization of Synthetic Phosphopeptides, Anal. Biochem., 270, 9, 1999. 

Amini, A., Chakraborty, A., Regnier, F.E. (2002). Simplification of complex tryptic digests for capillary electrophoresis by affinity selection of histidine-containing peptides with immobilized metal ion affinity chromatography. J. Chromatogr. B 772, 35-44. 

Porath, J. (1992) Immobilized metal ion affinity chromatography. Protein Expr. Purif. 3, 263-281. 

Porath, J., and Olin, B. (1983) Immobilized metal ion affinity adsorption and immobilized metal ion affinity chromatography of biomaterials. Serum protein affinities for gel-immobilized iron and nickel ions. Biochemistry 22, 1621-1630. 

Cao P. and Stults J.T. (1999), Phosphopeptide analysis by on-line immobilized metal-ion affinity chromatography-capillary electrophoresis-electrospray ionization mass spectrometry, J. Chromatogr. 853(1-2), 225-235. 

IMAP (immobilized metal ion affinity-based fluorescence polarization) Molecular Devices Trivalent metal ion containing beads bind to phosphorylated peptide producing FP signal change... 

LCA toward amino acids and nucleic bases has also been measured. Wesdemiotis and Cerda measured the alkali metal ion affinities of nucleobases in the gas phase from the dissociation of metal ion-bound heterodimers [nucleobase + B]M+, in which B represents a reference base of known affinity and M is an alkali metal. By assessing the dimer decomposition for two different internal energies, entropy is deconvoluted from enthalpy and LCA values are obtained. For guanine, cytosine, adenine, thymine and uracil, the corresponding Li+-nucleobase bond energies are as follows 57.2, 55.5, 54.1,... 

Todorova, D. and Vijayalakshmi, M. A., Immobilized metal-ion affinity chromatography, in Handbook of Affinity Chromatography, 2nd edn., Hage, D.S., Ed., CRC Press, Boca Raton, FL, 2005, Chap. 10. 

Chaga, G.S., Twenty-five years of immobilized metal ion affinity chromatography Past, present and future, J. Biochem. Biophys. Methods, 49, 313-334, 2001. 

High-Performance Metal Ion Affinity Chromatographic Separation of... 

Metal-chelate affinity chromatography (Immobilized-metal (Ion) affinity chromatography)... 

In 1970s, first application of metal-chelate affinity chromatography which is later named as "immobilized-metal (ion) affinity chromatography (IMAC) was perfomed. Metal-chelate chromatography technique exploits selective interactions and affinity between transition metal immobilized on a solid support (resin) via a metal chelator and amino acid residues which act as electron donors in the protein of interest [25-26]. As well as aromatic and heterocyclic compounds, proteins such as histidine, tyrosine, tyriptophane and phenylalanine posses affinity to transition metals which form complexes with compounds rich in electrons [25,27]. 

R. Woker, B. Champluvier, M. R. Kula, Purification of S-oxynitrilase from Sorghum hicolor by immobilized metal ion affinity chromatography on different carrier materials./. Chromatogr. 1992, 584, 85-92. 

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