Role of metal-binding proteins and peptides in bioremediation of toxic metals

Abstract Metal-binding proteins (MBP) and peptides are the molecules having ability to bind with heavy metals ions like cadmium (Cd), nickel (Ni), arsenic (As), and lead (Pb). MBPs remove heavy metals from the environment so that their hazardous effects are minimized. They have been exploited to enhance the metal accumulation by microorganisms especially bacteria because they respond to heavy metal stress by exclusion, compartmentalization, making complexes, or synthesis of binding proteins. There are several MBPs and peptides are known like, metallothioneins (MTs), phytochelatins (PCs), CdBP, CP, and HP. They eliminate heavy metals from the environment by making protein—metal ion complexes. Recently, transgenic plants have also been developed by using MTs from various sources for phytoremediation of heavy metal pollutants. Now the use of genetically modified plants for phytoremediation is getting popularity due to number of reasons. In this chapter the use of MBPs and peptides to eliminate heavy metals will be reviewed. Mechanisms of MBPs and peptides, their applications, and future scope will also be covered in the topic.