GPX1 (Glutathione Peroxidase 1) is a selenium-dependent antioxidant enzyme that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and corresponding alcohols. It is one of the most important cellular defenses against oxidative stress.
GPX1 is a tetrameric enzyme:
- Each subunit contains selenocysteine at active site (Sec75)
- Binds glutathione (GSH) as co-substrate
- Requires selenium for proper folding and activity
- Heme iron influences expression levels
GPX1 neutralizes ROS through:
- H2O2 reduction: Converts hydrogen peroxide to water
- Lipid peroxidation: Reduces lipid hydroperoxides
- Detoxification: Protects against oxidative damage
- Modulates H2O2-mediated signal transduction
- Prevents oxidation of protein thiols
- Protects DNA from oxidative damage
- Oxidative stress: GPX1 activity is reduced in AD brains
- Amyloid-beta: Aβ toxicity increases oxidative stress load
- Neuroprotection: Lower GPX1 correlates with disease progression
- Therapeutic target: Enhancing GPX1 may be protective
- DA neurons: High oxidative stress in dopaminergic neurons
- GPX1 variants: Genetic variations may affect PD risk
- Neuroprotection: Preserving GPX1 supports neuronal survival
- Oxidative damage: Motor neurons vulnerable to ROS
- SOD1 mutations: Interaction with GPX1 pathway
- Therapeutic potential: GPX1 activators in development
GPX1 is a crucial antioxidant enzyme that protects neurons from oxidative damage. In Alzheimer's and Parkinson's disease:
- GPX1 activity is reduced in AD brains
- GPX1 deficiency increases vulnerability to oxidative stress
- Therapeutic boosting of GPX1 may slow disease progression
GPX1 reduces hydrogen peroxide and lipid peroxides, preventing oxidative damage to neurons. Its dysfunction contributes to:
- Mitochondrial dysfunction
- Protein oxidation
- Lipid peroxidation
- DNA damage