Protein interactions metal chelating groups

Immunoglobulins G are a peculiar group of metal-interacting proteins as a result of the presence in their structure of a highly conserved histidyl cluster at the junctures of CH2 and CH3 domains of Fc fragment,186 and therefore they are easily adsorbed on metal chelating resins.187... 

Arnold and co-workers attempted to prepare imprinted metal-coordinating polymers for proteins [25]. For this purpose, efforts were made to prepare metalcoordinating molecularly patterned surfaces in mixed monolayers spread at the air-water interface or liposomes. This approach was termed as molecular printing and is illustrated in Fig. 6.6. In this process, a protein template is introduced into the aqueous phase, which imposes a pattern of functional amphiphiles in the surfactant monolayer via strong interactions with metal-chelating surfactant head groups. The pattern is then fixed by polymerising the surfactant tails. The technique has also been employed for two dimensional crystallisation of proteins [26]. 

The metals discussed in this chapter—lead, arsenic, mercury, and iron—frequently cause significant toxicity in humans. The toxicity profiles of metals differ, but most of their effects appear to result from interaction with sulfhydryl groups of enzymes and regulatory proteins. Chelators are organic compounds with two or more electronegative groups that can form stable covalent-coordinate bonds with cationic metal atoms. As emphasized in this chapter, these stable complexes can often be excreted readily, thus reducing the toxicity of the metal. 

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