regulation of hydrogen peroxide metabolic process

Definition

Target type: biologicalprocess

Any process that modulates the frequency, rate or extent of the chemical reactions and pathways involving hydrogen peroxide. [PMID:14765119]

Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS) that plays a dual role in biological systems. It can be both beneficial, acting as a signaling molecule involved in various cellular processes, and detrimental, causing oxidative stress and damage to cellular components. The regulation of H2O2 metabolism is crucial for maintaining cellular homeostasis and preventing oxidative damage. This regulation involves a complex interplay of enzymatic and non-enzymatic mechanisms.

Enzymatic regulation of H2O2 metabolism is primarily mediated by the following enzymes:

1. **Catalase:** This enzyme catalyzes the dismutation of H2O2 into water and oxygen. It is primarily located in peroxisomes, organelles responsible for the detoxification of H2O2. Catalase efficiently removes H2O2 at high concentrations, making it a crucial enzyme for H2O2 detoxification.

2. **Glutathione peroxidases (GPx):** GPx enzymes are a family of selenoproteins that catalyze the reduction of H2O2 to water using reduced glutathione (GSH) as a reducing agent. They are present in various cellular compartments and contribute to the removal of H2O2 at both high and low concentrations.

3. **Peroxiredoxins (Prx):** Prx enzymes are a family of thiol peroxidases that utilize reducing equivalents from thioredoxin (Trx) to reduce H2O2 to water. They are found in various cellular compartments and are important for controlling H2O2 signaling.

4. **Superoxide dismutases (SOD):** SOD enzymes catalyze the dismutation of superoxide radicals (O2-) into H2O2 and oxygen. While SODs do not directly remove H2O2, they play a role in regulating H2O2 levels by converting its precursor, superoxide.

5. **Other enzymes:** Other enzymes, such as NADPH oxidases (NOX) and cytochrome P450 monooxygenases, can contribute to H2O2 production during their normal metabolic activities.

Non-enzymatic regulation of H2O2 metabolism involves various mechanisms, including:

1. **Antioxidant molecules:** Molecules like glutathione (GSH), vitamin C (ascorbic acid), and vitamin E (α-tocopherol) can directly scavenge H2O2, reducing its concentration and oxidative potential.

2. **Protein thiol modifications:** H2O2 can react with cysteine residues in proteins, leading to the formation of sulfenic acid (SOH) modifications. These modifications can act as redox switches, regulating protein activity and cellular signaling pathways.

3. **Metal chelators:** Metals like iron and copper can catalyze the formation of H2O2 via the Fenton reaction. Metal chelators, such as transferrin and ferritin, bind to these metals and prevent their involvement in H2O2 production.

The regulation of H2O2 metabolism is a complex process involving multiple enzymatic and non-enzymatic mechanisms. It is essential for maintaining cellular homeostasis, preventing oxidative stress, and modulating signaling pathways involved in various cellular functions. Disruption of H2O2 homeostasis can contribute to the development of various diseases, including cancer, neurodegenerative disorders, and cardiovascular disease.'
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Proteins (1)

Compounds (16)