ABSTRACT
It is estimated that ~30% of a proteome binds to metal ion(s) for accomplishing its catalytic activities and structural complexities. Although metals are essential for the survival of a cell, they show cytotoxicity below or above a threshold concentration. In addition, toxic heavy metals, such as mercury and arsenic, present in the environment pose a higher level of toxicity to cells once inhaled, especially in humans. Thus, cells persistently produce a large number of metal-binding proteins to regulate the concentration and to detoxify the effect of toxic heavy metal ions inside the cell. Hence, for several years, metal-binding proteins, mostly from bacteria and plants, have been exploited for the bioremediation of water and land sites polluted by toxic heavy metals generally produced as by-products from various types of industries. Thus, the identification, characterization, and understanding of the molecular interaction(s) of metalloproteins with their cognate metal ions become necessary to design novel proteins/peptides to specifically chelate toxic heavy metals that could be used for bioremediation purposes. In this chapter, the aim is to describe and explore the existing knowledge of metal-binding proteins and peptides from different domains of life, which can be used for the bioremediation of heavy metal ions from the environment. It summarizes the structural view of the existing knowledge about various metal-binding proteins from different organisms in the prospect of bioremediation of toxic metals.
