Progress in the Biosynthesis and Metabolism of Glutathione

Glutathione( γ-L-glutamyl-L-cysteinylglycine,GSH),a tripeptide composed of glutamate,cysteine and glycine,is the most abundant non-protein thiol compound widely distributed in living organisms.There are too many papers on biosynthesis of glutathione. Glutathione is mainly synthesized by the consecutive action of γ-glutamylcysteine synthetase( GSH I) and glutathione synthetase( GSH II),whose evolutionary history is more complex than anticipated. Many organisms without GSH I or GSH II were proved to have the other biosynthetic patheways used to produce glutathione,while they also have complex metabolic pathway. This review summarizes the advance of the biosynthetic pathways and metabolisms of glutathione and the strategies to improve the intracellular level of glutathione using genetic engineering.