Phytochelatin Synthesis and Cadmium Remediation

Cadmium is a non-essential heavy metal pollutant. In biological systems, cadmium displaces calcium and zinc in proteins and can cause oxidative stress in an organism. This can cause severe damage to DNA and lipids.

Phytochelatin Synthesis Pathway:

Phytochelatins are thiol peptides with the primary structure: (gamma-Glu-Cys)n - Gly. These peptides are synthesized from glutathione, which also plays an important role in plant defense. Glutathiones are synthesized in two sequential ATP dependent reactions catalyzed by gamma-ECS and GS. Phytochelatin synthase subsequently catalyzes the elongation of the (gamma-Glu-Cys)n by transferring a gamma-Glu-Cys to glutathione or to PCs (figure above).

gamma-ECS = Glutamyl-cys synthetase
GS = Glutathione Sythetase

gamma-Glutamyl-cys synthetase (gamma-ECS), glutathione synthetase (GS), and phytochelatin synthase (PCS) have been investigated for their involvement in cadmium remediation.

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