Glutathione

Glutathione-skeletal.svg

Glutathione is a tripeptide composed of three amino acids: glutamine, cysteine, and glycine. It is an important antioxidant in plants, animals, fungi, and some bacteria and archaea, preventing damage to important cellular components caused by reactive oxygen species such as free radicals and peroxides.

Structure and Synthesis

Glutathione is synthesized in the body from its constituent amino acids. The synthesis occurs in two ATP-dependent steps:

1. The first step is the formation of gamma-glutamylcysteine from glutamate and cysteine, catalyzed by the enzyme gamma-glutamylcysteine synthetase.
2. The second step is the addition of glycine to gamma-glutamylcysteine, forming glutathione, catalyzed by the enzyme glutathione synthetase.

Functions

Glutathione has several important functions in the body:

• It acts as an antioxidant, neutralizing free radicals and reactive oxygen species.
• It is involved in the detoxification of harmful substances in the liver.
• It plays a role in the regeneration of other antioxidants, such as vitamin C and vitamin E.
• It is essential for the proper functioning of the immune system.
• It is involved in the synthesis and repair of DNA.

Clinical Significance

Glutathione levels can be affected by various factors, including age, diet, and disease. Low levels of glutathione have been associated with a number of health conditions, including:

• Parkinson's disease
• Alzheimer's disease
• Chronic obstructive pulmonary disease (COPD)
• HIV/AIDS
• Cancer

Supplementation

Glutathione supplements are available in various forms, including oral supplements, intravenous injections, and topical applications. However, the effectiveness of oral supplementation is debated due to the poor absorption of glutathione in the gastrointestinal tract.

See Also

• Antioxidant
• Reactive oxygen species
• Detoxification
• Immune system
• Amino acids