GO:0072541 peroxynitrite reductase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0072541 peroxynitrite reductase activity catalyzes the reduction of peroxynitrite (ONOO-) to nitrite (NO2-) and water using a protein dithiol, forming a protein disulfide.
• Bacterial peroxiredoxins were the first enzymes shown to possess this activity, establishing peroxiredoxins as peroxynitrite reductases.
• Selenoproteins such as glutathione peroxidase and thioredoxin reductase act as peroxynitrite reductases, linking selenium metabolism to peroxynitrite detoxification.
• Cytochrome c oxidase reduces peroxynitrite via a two-electron redox reaction at the heme a3-CuB site, connecting mitochondrial respiration to peroxynitrite turnover.
• Human erythrocyte peroxiredoxin 2 displays both peroxidase and peroxynitrite reductase activities, highlighting a role in red blood cell redox defense.
• Peroxynitrite reductase activity is central to intercepting peroxynitrite, a reactive nitrogen species implicated in oxidative damage and cell signaling.
Description
Peroxynitrite reductase activity (GO:0072541) is a molecular function that catalyzes the reaction: [protein]-dithiol + ONOO- = [protein]-disulfide + NO2- + H2O. This activity enables enzymes to detoxify peroxynitrite, a highly reactive nitrogen species formed from the diffusion-controlled reaction of nitric oxide and superoxide, by reducing it to nitrite and water while oxidizing protein thiols to disulfides. The term is synonymous with peroxynitritase activity and is classified under the molecular_function aspect of the Gene Ontology. Researchers study this activity because peroxynitrite contributes to oxidative and nitrative stress, and its reduction by dedicated enzymes represents a key protective mechanism in bacteria, mammals, and other organisms. The first described peroxynitrite reductases were bacterial peroxiredoxins, which use conserved cysteine residues to reduce peroxynitrite. Subsequent work identified selenoproteins, including glutathione peroxidase and thioredoxin reductase, as peroxynitrite reductases, expanding the repertoire of enzymes capable of this reaction. More recently, cytochrome c oxidase was shown to reduce peroxynitrite through a two-electron redox reaction at its heme a3-CuB site, linking mitochondrial bioenergetics to peroxynitrite detoxification. Human erythrocyte peroxiredoxin 2 also exhibits peroxynitrite reductase activity, underscoring the importance of this function in blood cells. Computational studies have provided mechanistic insights into how selenoprotein glutathione peroxidase catalyzes this reaction. Understanding peroxynitrite reductase activity is therefore relevant to redox biology, inflammation, neurodegeneration, and mitochondrial function.
peroxynitrite reductase activity At A Glance
| GO ID | GO:0072541 |
|---|---|
| GO term | peroxynitrite reductase activity |
| Ontology | molecular_function |
| Synonym | peroxynitritase activity |
| Definition | Catalysis of the reaction: [protein]-dithiol + ONOO- = [protein]-disulfide + NO2- + H2O. |
| Major function | Reduction of peroxynitrite to nitrite and water, with concomitant oxidation of protein thiols to disulfides. |
| Representative enzymes | Peroxiredoxins, glutathione peroxidase, thioredoxin reductase, cytochrome c oxidase. |
| Cofactors/redox centers | Protein cysteine thiols, selenocysteine, heme a3-CuB site. |
| Biological context | Oxidative and nitrative stress defense; reactive nitrogen species detoxification. |
What Is GO:0072541?
Peroxynitrite reductase activity (GO:0072541) is defined as the catalysis of the reaction: [protein]-dithiol + ONOO- = [protein]-disulfide + NO2- + H2O. In other words, it is the enzymatic reduction of peroxynitrite (ONOO-) to nitrite (NO2-) and water, coupled to the oxidation of a protein dithiol to a protein disulfide. This activity is synonymous with peroxynitritase activity and belongs to the molecular_function ontology.
Why Is peroxynitrite reductase activity Important in Cell Biology?
Peroxynitrite reductase activity is important because peroxynitrite is a potent oxidant and nitrating agent that can damage lipids, proteins, and DNA, and has been implicated in numerous pathological conditions. Enzymes with this activity, such as peroxiredoxins, glutathione peroxidase, thioredoxin reductase, and cytochrome c oxidase, provide a defense against peroxynitrite-mediated damage by converting it to less reactive nitrite and water. This function links cellular redox homeostasis, selenium metabolism, mitochondrial respiration, and antioxidant defense, making it a subject of intense research interest.
• Protects cells from peroxynitrite-mediated oxidative and nitrative damage.
• Links selenium metabolism to peroxynitrite detoxification via selenoproteins.
• Connects mitochondrial respiration to peroxynitrite turnover through cytochrome c oxidase.
• Involved in red blood cell redox defense via peroxiredoxin 2.
• Provides a mechanism for bacterial resistance to nitrosative stress through peroxiredoxins.
• Represents a target for understanding inflammation and neurodegeneration associated with peroxynitrite.
• Offers a paradigm for thiol-based redox regulation and signaling.
• Enables computational and biochemical studies of enzyme mechanisms.
• Highlights the role of selenocysteine in antioxidant catalysis.
• Supports research on thioredoxin reductase and ebselen as peroxynitrite reductases.
Molecular Mechanism of peroxynitrite reductase activity
Substrate binding and thiol oxidation
In simple terms: The enzyme uses its own sulfur-containing residues to grab and break down peroxynitrite.
In peroxynitrite reductase activity, a protein dithiol serves as the electron donor for the reduction of peroxynitrite. The reaction converts the dithiol to a disulfide while reducing ONOO- to NO2- and H2O. Bacterial peroxiredoxins were the first enzymes shown to catalyze this reaction, utilizing conserved cysteine residues. Human erythrocyte peroxiredoxin 2 also displays this activity, indicating that the thiol-based mechanism is conserved.
Role of selenocysteine in selenoprotein peroxynitrite reductases
In simple terms: Some enzymes use selenium instead of sulfur to neutralize peroxynitrite more efficiently.
Selenoproteins such as glutathione peroxidase and thioredoxin reductase act as peroxynitrite reductases. The presence of selenocysteine is critical for this function, as demonstrated by the protection against peroxynitrite-mediated oxidations by glutathione peroxidase. Computational studies have provided insights into the reaction mechanism of selenoprotein glutathione peroxidase with peroxynitrite. Thioredoxin reductase can also function as a peroxynitrite reductase using selenocystine or ebselen.
Two-electron redox reaction at heme a3-CuB site
In simple terms: Cytochrome c oxidase uses a metal center to donate two electrons to peroxynitrite.
Cytochrome c oxidase exhibits peroxynitrite reductase activity through a two-electron redox reaction at the heme a3-CuB site. This reaction links the terminal step of the mitochondrial electron transport chain to peroxynitrite detoxification. The heme a3-CuB binuclear center is the catalytic site for both oxygen reduction and peroxynitrite reduction.
Regulation by redox state and substrate availability
In simple terms: The activity depends on the cell's redox balance and the amount of peroxynitrite present.
The peroxynitrite reductase activity of these enzymes is influenced by the cellular redox environment, including the availability of reducing equivalents such as thioredoxin and glutathione. Peroxiredoxin 2 activity in erythrocytes is linked to the redox state of the cell. Thioredoxin reductase requires selenocystine or ebselen for its peroxynitrite reductase function, indicating that cofactor availability regulates activity. The balance between peroxynitrite formation and interception determines the overall impact on cell signaling and damage.
Key Genes Involved in GO:0072541 peroxynitrite reductase activity
The following genes and proteins are experimentally linked to peroxynitrite reductase activity (GO:0072541) based on the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PRDX (bacterial peroxiredoxin) | Peroxynitrite reductase; reduces ONOO- to NO2- using cysteine thiols | First identified peroxynitrite reductase; model for thiol-based detoxification |
| GPX (glutathione peroxidase) | Selenoprotein peroxynitrite reductase; protects against peroxynitrite-mediated oxidations | Key selenoprotein with peroxynitrite reductase activity; computational studies of mechanism |
| TXNRD (thioredoxin reductase) | Peroxynitrite reductase using selenocystine or ebselen | Expands role of thioredoxin system in peroxynitrite detoxification |
| COX (cytochrome c oxidase) | Peroxynitrite reductase via two-electron redox at heme a3-CuB | Links mitochondrial respiration to peroxynitrite turnover |
| PRDX2 (peroxiredoxin 2) | Human erythrocyte peroxidase and peroxynitrite reductase | Red blood cell redox defense; both peroxidase and peroxynitrite reductase activities |
| Selenoproteins (general) | Peroxynitrite reductase activity | Protection against peroxynitrite by selenoproteins |
| Peroxiredoxins (family) | Peroxynitrite reductase activity | Bacterial and human peroxiredoxins share this activity |
| Glutathione peroxidase (GPX) | Peroxynitrite reductase | Selenoprotein with new function as peroxynitrite reductase |
| Thioredoxin reductase (TXNRD) | Peroxynitrite reductase | Uses selenocystine or ebselen as cofactors |
| Cytochrome c oxidase (COX) | Peroxynitrite reductase | Two-electron redox at heme a3-CuB site |
| PRDX (bacterial) | Peroxynitrite reductase | First described peroxynitrite reductase |
| PRDX2 (human) | Peroxynitrite reductase | Erythrocyte enzyme with dual activities |
| GPX (selenoprotein) | Peroxynitrite reductase | Computational study of mechanism |
| TXNRD (selenoprotein) | Peroxynitrite reductase | Selenocystine/ebselen-dependent |
| COX (mitochondrial) | Peroxynitrite reductase | Heme a3-CuB site |
| Selenoprotein (general) | Peroxynitrite reductase | Protection against peroxynitrite |
How Is peroxynitrite reductase activity Regulated?
Peroxynitrite reductase activity is regulated by the availability of reducing equivalents and cofactors. For example, thioredoxin reductase requires selenocystine or ebselen to function as a peroxynitrite reductase. The activity of peroxiredoxin 2 in erythrocytes is influenced by the cellular redox state. Selenoprotein glutathione peroxidase activity depends on selenium availability. Additionally, the expression and activity of these enzymes can be modulated by oxidative stress and inflammatory signals that increase peroxynitrite formation.
peroxynitrite reductase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PRDX2 | Erythrocyte oxidative stress | PRDX2 knockout or overexpression in erythroid cells |
| GPX | Neurodegeneration, inflammation | GPX knockout mice or neuronal cell lines |
| TXNRD | Oxidative stress, cardiovascular disease | TXNRD knockout or selenocystine/ebselen treatment |
| COX | Mitochondrial dysfunction | COX point mutations at heme a3-CuB site |
| Bacterial PRDX | Bacterial nitrosative stress resistance | Bacterial PRDX knockout |
Peroxynitrite reductase activity in oxidative stress and inflammation
Peroxynitrite is a reactive nitrogen species implicated in oxidative damage and inflammation. Enzymes with peroxynitrite reductase activity, such as peroxiredoxins, glutathione peroxidase, and thioredoxin reductase, help mitigate peroxynitrite-mediated damage. Loss of these activities may exacerbate inflammatory tissue injury.
Role in neurodegeneration
Peroxynitrite has been linked to neurodegenerative processes. Selenoproteins with peroxynitrite reductase activity, including glutathione peroxidase, may protect neurons from peroxynitrite-mediated damage. Cytochrome c oxidase, which also exhibits this activity, is critical for mitochondrial function in neurons.
Cardiovascular and erythrocyte biology
Human erythrocyte peroxiredoxin 2 displays peroxynitrite reductase activity, suggesting a role in protecting red blood cells from peroxynitrite during oxidative stress. Thioredoxin reductase and glutathione peroxidase may also contribute to vascular protection by reducing peroxynitrite.
From peroxynitrite reductase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of peroxynitrite reductase activity increase peroxynitrite damage? | Knockout of PRDX, GPX, or TXNRD in cell lines |
| What is the catalytic role of specific cysteine or selenocysteine residues? | Point mutation of catalytic residues in PRDX or GPX |
| Can a tagged enzyme be used to monitor peroxynitrite reductase activity? | Knock-in of epitope-tagged PRDX2 or GPX |
| Does overexpression of a peroxynitrite reductase protect against oxidative stress? | Overexpression of PRDX2, GPX, or TXNRD in cultured cells |
| How does cytochrome c oxidase peroxynitrite reductase activity affect mitochondrial function? | Point mutations in COX heme a3-CuB site |
| Can bacterial peroxiredoxin complement eukaryotic peroxynitrite reductase deficiency? | Knock-in of bacterial PRDX into eukaryotic cells |
How to Study the peroxynitrite reductase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Peroxynitrite consumption assay | Reduction of ONOO- to NO2- | Measure peroxynitrite reductase activity of purified enzymes |
| Nitrite quantification | Formation of NO2- | Assess enzyme activity |
| Computational modeling | Reaction mechanism | Study selenoprotein glutathione peroxidase |
| Redox titrations | Two-electron redox at heme a3-CuB | Cytochrome c oxidase activity |
| Selenium status analysis | Selenoprotein expression | Regulation of peroxynitrite reductase |
| Thioredoxin reductase assay | Selenocystine/ebselen-dependent activity | Measure peroxynitrite reductase |
| Cell viability under oxidative stress | Protection against peroxynitrite | Evaluate peroxiredoxin 2 or GPX overexpression |
| Erythrocyte assays | Peroxiredoxin 2 activity | Red blood cell redox defense |
Enzymatic assays for peroxynitrite reductase activity
Peroxynitrite reductase activity can be measured by monitoring the disappearance of peroxynitrite or the formation of nitrite. Bacterial peroxiredoxins were assayed using such methods. Human erythrocyte peroxiredoxin 2 activity was measured similarly. Cytochrome c oxidase activity was assessed by two-electron redox reaction at the heme a3-CuB site.
Computational and structural approaches
Computational studies have been used to investigate the mechanism of peroxynitrite reductase activity of selenoprotein glutathione peroxidase. Structural analysis of the heme a3-CuB site in cytochrome c oxidase provides insights into peroxynitrite reduction.
Redox and selenium status measurements
Selenium status and selenoprotein expression can be assessed to understand regulation of peroxynitrite reductase activity. Thioredoxin reductase activity using selenocystine or ebselen can be measured.
Cell-based oxidative stress models
Cells exposed to peroxynitrite donors or oxidative stress can be used to evaluate the protective role of peroxynitrite reductases. Erythrocytes are a natural model for peroxiredoxin 2 function.
How CRISPR Can Be Used to Study GO:0072541 peroxynitrite reductase activity
Knockout
CRISPR knockout of genes encoding peroxynitrite reductases, such as PRDX2, GPX, or TXNRD, can be used to assess loss of peroxynitrite detoxification and increased sensitivity to oxidative stress. Bacterial PRDX knockouts can reveal roles in nitrosative stress resistance.
Point Mutation
Point mutations of catalytic cysteine or selenocysteine residues in peroxiredoxins or glutathione peroxidase can abolish peroxynitrite reductase activity, allowing structure-function studies. Mutations in the heme a3-CuB site of cytochrome c oxidase can disrupt its peroxynitrite reductase activity.
Knock-in
Knock-in of epitope-tagged peroxynitrite reductases, such as PRDX2 or GPX, enables monitoring of protein localization and activity. Knock-in of bacterial PRDX into eukaryotic cells can test functional conservation.
Overexpression
Overexpression of peroxynitrite reductases like PRDX2, GPX, or TXNRD can protect cells from peroxynitrite-mediated damage and is useful for gain-of-function studies. Overexpression of cytochrome c oxidase components may enhance mitochondrial peroxynitrite reduction.
How EDITGENE Supports peroxynitrite reductase activity Research
Researchers studying peroxynitrite reductase activity-related genes often need to determine whether a candidate gene is causally involved in peroxynitrite detoxification, redox signaling, or disease protection. EDITGENE provides comprehensive CRISPR-based services to generate knockout, point-mutation, knock-in, and overexpression cell models, as well as CRISPR library screening and bioinformatics support, to accelerate functional studies of peroxynitrite reductase activity.
Contact EDITGENE today to design your custom CRISPR model for peroxynitrite reductase activity research.
Frequently Asked Questions About peroxynitrite reductase activity
What is peroxynitrite reductase activity?
Peroxynitrite reductase activity (GO:0072541) is the catalysis of the reaction: [protein]-dithiol + ONOO- = [protein]-disulfide + NO2- + H2O, reducing peroxynitrite to nitrite and water.
What genes are involved in peroxynitrite reductase activity?
Genes encoding peroxiredoxins (e.g., PRDX2), glutathione peroxidase (GPX), thioredoxin reductase (TXNRD), and cytochrome c oxidase (COX) are involved.
Which enzymes have peroxynitrite reductase activity?
Bacterial peroxiredoxins, human peroxiredoxin 2, glutathione peroxidase, thioredoxin reductase, and cytochrome c oxidase all exhibit this activity.
How is peroxynitrite reductase activity measured?
It can be measured by monitoring peroxynitrite consumption, nitrite formation, or using computational and redox assays.
What is the role of selenium in peroxynitrite reductase activity?
Selenoproteins such as glutathione peroxidase and thioredoxin reductase use selenocysteine for peroxynitrite reduction, linking selenium to detoxification.
Is peroxynitrite reductase activity involved in disease?
Yes, it is implicated in oxidative stress, inflammation, neurodegeneration, and erythrocyte protection.
What is the GO ID for peroxynitrite reductase activity?
The GO ID is GO:0072541.
What is the synonym for peroxynitrite reductase activity?
The synonym is peroxynitritase activity.
How does cytochrome c oxidase reduce peroxynitrite?
Cytochrome c oxidase reduces peroxynitrite via a two-electron redox reaction at the heme a3-CuB site.
Can CRISPR be used to study peroxynitrite reductase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can be used to study genes involved in peroxynitrite reductase activity.
Conclusion
Peroxynitrite reductase activity (GO:0072541) is a critical enzymatic function that detoxifies peroxynitrite, a reactive nitrogen species linked to oxidative damage and disease. Key enzymes include bacterial and human peroxiredoxins, selenoprotein glutathione peroxidase, thioredoxin reductase, and cytochrome c oxidase. Understanding this activity provides insights into redox biology, inflammation, and neurodegeneration. CRISPR-based models from EDITGENE can accelerate research into the genes and mechanisms underlying peroxynitrite reductase activity.
References
- 1. Bryk R et al.. 2000. Peroxynitrite reductase activity of bacterial peroxiredoxins.. Nature 407(6801):211-5 PMID: 11001062
- 2. Speckmann B et al.. 2016. Peroxynitrite: From interception to signaling.. Arch Biochem Biophys 595:153-60 PMID: 27095233
- 3. Prabhakar R et al.. 2006. Peroxynitrite reductase activity of selenoprotein glutathione peroxidase: a computational study.. Biochemistry 45(22):6967-77 PMID: 16734432
- 4. Pearce LL et al.. 1999. The peroxynitrite reductase activity of cytochrome c oxidase involves a two-electron redox reaction at the heme a(3)-Cu(B) site.. J Biol Chem 274(50):35763-7 PMID: 10585458
- 5. Manta B et al.. 2009. The peroxidase and peroxynitrite reductase activity of human erythrocyte peroxiredoxin 2.. Arch Biochem Biophys 484(2):146-54 PMID: 19061854
- 6. Sies H et al.. 1997. Glutathione peroxidase protects against peroxynitrite-mediated oxidations. A new function for selenoproteins as peroxynitrite reductase.. J Biol Chem 272(44):27812-7 PMID: 9346926
- 7. Sies H et al.. 1998. Protection against peroxynitrite by selenoproteins.. Z Naturforsch C J Biosci 53(3-4):228-32 PMID: 9618937
- 8. Arteel GE et al.. 1999. Function of thioredoxin reductase as a peroxynitrite reductase using selenocystine or ebselen.. Chem Res Toxicol 12(3):264-9 PMID: 10077489
