GO:0004601 peroxidase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004601 peroxidase activity is a molecular function defined as catalysis of the reaction: a reduced substrate + ROOH = an oxidized substrate + ROH + H2O.
• The term covers heme peroxidases, plant secretory peroxidases, myeloperoxidase (MPO), eosinophil peroxidase, lactoperoxidase, horseradish peroxidase (HRP) and related enzymes.
• Peroxidase activity controls hydrogen peroxide and organic hydroperoxide levels, protecting cells from oxidative damage while also generating reactive oxidants for host defense and signaling.
• Human hemoproteins such as hemoglobin, myoglobin and cytochrome c can display peroxidase activity, and this side activity must be kept under control to avoid oxidative damage.
• Nanomaterials and metal-organic frameworks can mimic peroxidase activity, creating nanozymes for biosensing, bioanalysis and pollutant removal.
• CRISPR knockout, point-mutation, knock-in and overexpression models allow causal testing of peroxidase genes in oxidative stress, inflammation and disease.
Description
Peroxidase activity (GO:0004601) is a molecular function in which an enzyme catalyzes the reduction of a hydroperoxide (ROOH) to the corresponding alcohol (ROH) and water while oxidizing a reduced substrate. The reaction is central to redox biology because it removes hydrogen peroxide and organic hydroperoxides, which are damaging when they accumulate, and because some peroxidases deliberately produce oxidizing species for host defense and signaling. The QuickGO definition captures this chemistry precisely: a reduced substrate + ROOH = an oxidized substrate + ROH + H2O. Researchers study this term because peroxidases sit at the intersection of antioxidant defense, inflammation, innate immunity and cellular signaling, and because their activity can be measured with simple colorimetric and fluorogenic substrates. The same catalytic chemistry is also found outside classical enzymes: human hemoproteins such as hemoglobin and myoglobin exhibit peroxidase activity, and this reactivity is tightly controlled to prevent unwanted oxidative damage. In parallel, synthetic nanozymes and metal-organic frameworks with peroxidase-like activity are being engineered for biosensing, bioanalysis and environmental applications, making GO:0004601 relevant to both biology and materials science.
peroxidase activity At A Glance
| GO ID | GO:0004601 |
|---|---|
| GO term | peroxidase activity |
| Ontology | molecular_function |
| Definition | Catalysis of the reaction: a reduced substrate + ROOH = an oxidized substrate + ROH + H2O. |
| Common synonyms | heme peroxidase, horseradish peroxidase (HRP), myeloperoxidase activity (MPO), lactoperoxidase activity, eosinophil peroxidase activity, guaiacol peroxidase, thiocyanate peroxidase, verdoperoxidase |
| Representative enzymes | Myeloperoxidase (MPO), eosinophil peroxidase (EPX), lactoperoxidase (LPO), thyroid peroxidase (TPO), glutathione peroxidase (GPX), catalase (CAT), horseradish peroxidase (HRP) |
| Reaction type | Oxidoreduction using a hydroperoxide (ROOH) as the electron acceptor |
| Major substrates | Hydrogen peroxide (H2O2), organic hydroperoxides, halides, thiocyanate, aromatic donors such as guaiacol and scopoletin |
| Related chemistry | Catalase-peroxidase, protoheme peroxidase, oxyperoxidase and nanozyme peroxidase mimics |
What Is GO:0004601?
In the Gene Ontology, GO:0004601 peroxidase activity is defined as catalysis of the reaction: a reduced substrate + ROOH = an oxidized substrate + ROH + H2O. In other words, a peroxidase uses a hydroperoxide as the oxidant and transfers the oxidizing equivalent to a donor substrate, converting the hydroperoxide to an alcohol and water. The term is a molecular_function and includes heme peroxidases, secretory plant peroxidases, myeloperoxidase, eosinophil peroxidase, lactoperoxidase, horseradish peroxidase and many related activities listed as synonyms. Because the definition is reaction-based, it applies to classical heme enzymes, non-heme peroxidases and even engineered or nanomaterial-based catalysts that reproduce the same net chemistry.
Why Is peroxidase activity Important in Cell Biology?
Peroxidase activity matters because it determines the fate of hydrogen peroxide and organic hydroperoxides in cells. When these species are removed efficiently, they are harmless metabolic byproducts; when they accumulate or are converted into more reactive oxidants, they can damage lipids, proteins and DNA. Human hemoproteins such as hemoglobin and myoglobin possess peroxidase activity that must be kept under control to avoid oxidative damage, illustrating why this activity is both useful and potentially dangerous. At the same time, peroxidases are exploited in biotechnology and diagnostics, and synthetic systems with peroxidase-like activity are being developed for sensing, bioanalysis and pollutant degradation. Understanding GO:0004601 therefore connects fundamental redox biology to disease mechanisms and to applied bioengineering.
• Controls hydrogen peroxide and organic hydroperoxide levels, limiting oxidative damage to lipids, proteins and DNA.
• Supports innate immunity through myeloperoxidase and related enzymes that generate antimicrobial oxidants.
• Contributes to thyroid hormone biosynthesis via thyroid peroxidase, a heme peroxidase family member.
• Human hemoproteins such as hemoglobin and myoglobin show peroxidase activity that must be regulated to prevent unwanted oxidation.
• Provides widely used reporter enzymes such as horseradish peroxidase (HRP) for immunoassays and histochemistry.
• Inspires nanozymes and metal-organic frameworks with peroxidase-like activity for biosensing and bioanalysis.
• Enables environmental applications such as removal of aflatoxin B1 using peroxidase-like metal-organic frameworks.
• Serves as a model system for studying heme chemistry, radical intermediates and enzyme evolution.
• Links redox balance to inflammation, neurodegeneration and cancer biology through MPO and related enzymes.
• Offers measurable activity readouts (colorimetric, fluorogenic, chemiluminescent) that make it tractable for high-throughput screening.
Molecular Mechanism of peroxidase activity
Substrate binding and hydroperoxide activation
In simple terms: The enzyme first grabs a peroxide molecule and activates it.
In classical heme peroxidases, the resting ferric enzyme binds a hydroperoxide (ROOH) in the distal heme pocket. The distal histidine and arginine residues polarize the O-O bond, promoting heterolytic cleavage. This step converts the ferric enzyme to Compound I, an oxyferryl porphyrin radical species. The same net chemistry is reproduced by non-heme peroxidases and by nanozymes with peroxidase-like activity, although the detailed intermediates differ.
Oxidation of the donor substrate
In simple terms: The activated enzyme then passes the oxidizing power to another molecule.
Compound I oxidizes a reduced donor substrate, generating a substrate radical and returning the enzyme to Compound II. A second donor molecule reduces Compound II back to the resting ferric state, completing the catalytic cycle. Donors can be halides, thiocyanate, aromatic compounds such as guaiacol, or protein residues. This two-step ping-pong mechanism explains why peroxidase activity is measured with colorimetric substrates that change color upon oxidation.
Heme cofactor and distal pocket residues
In simple terms: A heme iron and a few key amino acids do the chemical work.
Most classical peroxidases contain a protoheme IX cofactor coordinated by a proximal histidine. The distal pocket typically contains a histidine and an arginine that stabilize the hydroperoxide and facilitate O-O cleavage. Mutating these residues reduces or abolishes activity, which is why they are frequent targets for point-mutation studies. The term protoheme peroxidase is a synonym of GO:0004601, reflecting the importance of this cofactor.
Non-heme and nanozyme peroxidase mimics
In simple terms: Not every peroxidase uses heme; some are metals or nanomaterials.
Glutathione peroxidases use selenocysteine instead of heme, and many synthetic nanomaterials reproduce peroxidase-like chemistry. Single-atom nanozymes, platinum nanoparticles, cobalt-quinaldic acid complexes, multimetallic nanorattles and metal-organic frameworks have all been reported to catalyze peroxidase-like reactions. These systems are studied for biosensing, bioanalysis and pollutant removal, and they illustrate that the GO:0004601 reaction definition is chemistry-based rather than sequence-based.
Regulation by substrate availability and redox environment
In simple terms: How much peroxide is around, and how reducing the cell is, controls the reaction.
Peroxidase activity depends on the local concentration of hydroperoxides, the availability of reducing donors such as glutathione or thiocyanate, and the redox state of the compartment. In human hemoproteins, uncontrolled peroxidase activity can promote oxidative damage, so cells maintain reducing systems to keep this chemistry in check. In engineered nanozyme systems, activity can be tuned by pH, metal composition and surface ligands, which is why DNA-encoded and ligand-modulated regulation has been explored.
Key Genes Involved in GO:0004601 peroxidase activity
The following genes and proteins represent the main classes of enzymes and catalysts associated with GO:0004601 peroxidase activity.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MPO | Myeloperoxidase; neutrophil heme peroxidase that generates hypochlorous acid | Inflammation, innate immunity, cardiovascular and neurodegenerative disease models |
| EPX | Eosinophil peroxidase; eosinophil-specific heme peroxidase | Asthma, allergy and eosinophilic disorder models |
| LPO | Lactoperoxidase; secreted heme peroxidase in milk and saliva | Antimicrobial defense and food preservation studies |
| TPO | Thyroid peroxidase; heme peroxidase required for thyroid hormone synthesis | Thyroid disease and congenital hypothyroidism models |
| GPX1 | Glutathione peroxidase 1; selenocysteine peroxidase that reduces H2O2 | Oxidative stress, cancer and neurodegeneration models |
| GPX4 | Glutathione peroxidase 4; lipid hydroperoxide reductase | Ferroptosis and lipid peroxidation research |
| CAT | Catalase; heme enzyme that decomposes H2O2 | Oxidative stress and peroxisomal biology models |
| PRDX1 | Peroxiredoxin 1; non-heme thiol peroxidase | Redox signaling and cancer models |
| PRDX2 | Peroxiredoxin 2; red blood cell peroxidase | Hemolytic anemia and oxidative stress models |
| PRDX3 | Peroxiredoxin 3; mitochondrial peroxidase | Mitochondrial redox biology models |
| PRDX4 | Peroxiredoxin 4; endoplasmic reticulum peroxidase | ER redox and secretory pathway models |
| PRDX5 | Peroxiredoxin 5; mitochondrial and cytosolic peroxidase | Broad antioxidant defense models |
| PRDX6 | Peroxiredoxin 6; bifunctional peroxidase and phospholipase A2 | Lung surfactant and lipid peroxidation models |
| HRP | Horseradish peroxidase; plant secretory peroxidase widely used as a reporter | Immunoassays, histochemistry and biosensor development |
| Cytochrome c | Mitochondrial hemoprotein with peroxidase activity when released | Apoptosis and mitochondrial oxidative stress models |
| Hemoglobin | Oxygen carrier with intrinsic peroxidase side activity | Hemolysis and oxidative damage studies |
| Myoglobin | Muscle oxygen carrier with peroxidase side activity | Rhabdomyolysis and cardiac injury models |
How Is peroxidase activity Regulated?
Peroxidase activity is regulated at multiple levels. Substrate availability, especially the local concentration of hydrogen peroxide and organic hydroperoxides, sets the reaction rate. Reducing co-substrates such as glutathione, thiocyanate and halides determine which donor is oxidized. In human hemoproteins, peroxidase side activity is kept under control by cellular reducing systems and by compartmentalization, because uncontrolled activity can cause oxidative damage. In engineered nanozyme systems, activity can be tuned by pH, metal composition, surface ligands and DNA encoding, as shown for platinum and cobalt-based catalysts. Transcriptional and post-translational control of peroxidase enzymes, including selenoprotein synthesis for glutathione peroxidases, adds a further layer of regulation.
peroxidase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| MPO | Inflammation, cardiovascular injury, neurodegeneration | MPO knockout and point-mutation cell models in neutrophils or macrophage-like cells |
| GPX4 | Ferroptosis, lipid peroxidation, cancer | GPX4 knockout and inducible overexpression models in cancer cell lines |
| TPO | Congenital hypothyroidism, autoimmune thyroid disease | TPO knock-in and point-mutation models in thyroid cell lines |
| PRDX1 | Cancer, oxidative stress, hemolytic anemia | PRDX1 knockout and tagged knock-in models in erythroid and cancer cells |
| Cytochrome c | Apoptosis, mitochondrial oxidative stress | Point-mutation models that separate electron transport from peroxidase activity |
Inflammation and innate immunity
Myeloperoxidase (MPO) and eosinophil peroxidase (EPX) generate hypohalous acids and other oxidants that kill pathogens but can also damage host tissue. Dysregulated peroxidase activity is therefore linked to chronic inflammatory diseases, cardiovascular injury and tissue damage. Human hemoproteins such as hemoglobin and myoglobin can also contribute to oxidative damage when their peroxidase activity is not controlled.
Neurodegeneration and oxidative stress
Oxidative stress is a common feature of neurodegenerative conditions, and peroxidases that remove hydrogen peroxide and lipid hydroperoxides are protective. Conversely, excessive heme peroxidase activity, including that of MPO and released hemoproteins, can promote neuronal damage. Glutathione peroxidase 4 (GPX4) is particularly important because loss of its lipid peroxidase activity triggers ferroptosis, a form of regulated cell death.
Cancer and redox balance
Cancer cells often reprogram redox metabolism to tolerate high levels of reactive oxygen species. Peroxidases such as PRDX1, PRDX2 and GPX1 support this adaptation, and their inhibition is being explored as a therapeutic strategy. At the same time, MPO-derived oxidants can cause DNA damage that contributes to mutagenesis.
Thyroid and metabolic disease
Thyroid peroxidase (TPO) is essential for thyroid hormone biosynthesis, and TPO dysfunction causes congenital hypothyroidism and autoimmune thyroid disease. This makes TPO a clinically important example of a heme peroxidase with a dedicated biosynthetic role.
From peroxidase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is a candidate peroxidase gene required for hydrogen peroxide clearance? | CRISPR knockout cell line plus H2O2 challenge and colorimetric peroxidase assay |
| Does a specific distal pocket residue control catalytic efficiency? | Point-mutation knock-in of the catalytic residue followed by kinetic analysis |
| Does a disease-associated variant alter peroxidase activity? | Knock-in of the patient variant and comparison with wild-type isogenic control |
| Where is the peroxidase enzyme localized in the cell? | Tagged knock-in with fluorescent or epitope tag and imaging |
| Does overexpression of a peroxidase protect against oxidative stress? | Doxycycline-inducible overexpression cell line with viability and lipid peroxidation readouts |
| Which genes modify sensitivity to peroxidase inhibition? | CRISPR library screening with a peroxidase inhibitor and next-generation sequencing readout |
How to Study the peroxidase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Colorimetric peroxidase assay | Oxidation of guaiacol or ABTS by hydroperoxide | Routine activity measurement in lysates and purified enzymes |
| Amplex Red assay | Hydrogen peroxide consumption or production | High-throughput screening of peroxidase activity |
| CRISPR knockout | Loss-of-function phenotype | Testing whether a peroxidase gene is required for stress resistance |
| Point-mutation knock-in | Effect of a specific residue or variant | Structure-function analysis of catalytic residues |
| Tagged knock-in | Protein localization and interaction | Imaging and co-immunoprecipitation studies |
| RNA-seq | Transcriptional response of peroxidase genes | Comparing oxidative stress conditions across cell types |
| Proteomics | Protein abundance and modification | Detecting oxidative modifications of peroxidase enzymes |
| CRISPR library screening | Genome-wide modifiers of peroxidase-related phenotypes | Identifying synthetic lethal or resistance genes |
Enzymatic activity assays
Peroxidase activity is commonly measured with colorimetric or fluorogenic substrates such as guaiacol, scopoletin, Amplex Red or luminol. These assays detect the oxidized product and can be adapted to plate readers for high-throughput screening. They are the primary readout for GO:0004601 in cell lysates and purified preparations.
Genetic perturbation and CRISPR screens
CRISPR knockout, point mutation, knock-in and overexpression allow causal testing of peroxidase genes. Pooled CRISPR library screening can identify genes that modify sensitivity to oxidative stress or to peroxidase inhibitors, and the resulting hits can be validated with individual clones.
Transcriptomics and proteomics
RNA-seq and quantitative proteomics reveal how peroxidase genes are expressed across conditions and tissues. These methods help distinguish transcriptional regulation from post-translational control of enzyme activity and can identify co-regulated antioxidant networks.
Imaging and redox biosensors
Genetically encoded redox sensors and fluorescent probes can report hydrogen peroxide and lipid peroxidation in live cells. Combined with tagged knock-in of peroxidase enzymes, imaging reveals where the activity occurs and how it responds to stimuli.
How CRISPR Can Be Used to Study GO:0004601 peroxidase activity
Knockout
CRISPR knockout of a peroxidase gene removes the enzyme and allows direct testing of its contribution to hydrogen peroxide clearance, oxidative stress resistance and disease phenotypes. Isogenic wild-type controls are essential to separate on-target effects from clonal variation.
Point Mutation
Point-mutation knock-in can change a single catalytic residue, such as the distal histidine or arginine in a heme peroxidase, to test its role in hydroperoxide activation. This approach is also used to model disease-associated missense variants and to separate peroxidase activity from other functions of the same protein.
Knock-in
Knock-in of a fluorescent or epitope tag enables localization and interaction studies without altering the endogenous regulatory context. Knock-in of a patient variant into the endogenous locus provides a physiologically relevant disease model.
Overexpression
Inducible overexpression of a peroxidase gene can test whether increased activity protects cells from oxidative stress or alters signaling. Overexpression models are also useful for producing recombinant enzyme for biochemical and structural studies.
How EDITGENE Supports peroxidase activity Research
Researchers studying peroxidase activity-related genes often need to determine whether a candidate gene is causally involved in oxidative stress, inflammation or disease, and that requires precise, isogenic cell models. EDITGENE provides the full range of CRISPR-engineered cell lines needed to move from correlation to causation.
Contact EDITGENE today to design your custom CRISPR model for peroxidase activity research.
Frequently Asked Questions About peroxidase activity
What is peroxidase activity?
Peroxidase activity (GO:0004601) is a molecular function defined as catalysis of the reaction: a reduced substrate + ROOH = an oxidized substrate + ROH + H2O. It removes hydroperoxides while oxidizing a donor substrate.
What genes are involved in peroxidase activity?
Key genes include MPO, EPX, LPO, TPO, GPX1, GPX4, CAT, PRDX1-6 and the plant reporter enzyme HRP. Human hemoproteins such as hemoglobin and myoglobin also show peroxidase activity.
What is the GO ID for peroxidase activity?
The Gene Ontology identifier for peroxidase activity is GO:0004601, and its ontology aspect is molecular_function.
What is the difference between peroxidase and catalase?
Both enzymes act on hydrogen peroxide, but catalase dismutates H2O2 into water and oxygen, whereas a peroxidase reduces a hydroperoxide while oxidizing a separate donor substrate, as defined for GO:0004601.
How is peroxidase activity measured?
Common assays use colorimetric or fluorogenic substrates such as guaiacol, ABTS, Amplex Red or luminol, which change signal upon oxidation by the enzyme.
What diseases are linked to peroxidase activity?
Myeloperoxidase and related peroxidases are linked to inflammation, cardiovascular injury and neurodegeneration, while GPX4 loss causes ferroptosis and TPO dysfunction causes thyroid disease.
Can nanomaterials have peroxidase activity?
Yes. Single-atom nanozymes, platinum nanoparticles, cobalt complexes, multimetallic nanorattles and metal-organic frameworks have all been reported to catalyze peroxidase-like reactions.
What is horseradish peroxidase used for?
Horseradish peroxidase (HRP) is a plant secretory peroxidase widely used as a reporter enzyme in immunoassays, histochemistry and biosensors.
How do CRISPR models help study peroxidase activity?
CRISPR knockout, point mutation, knock-in and overexpression allow causal testing of peroxidase genes in oxidative stress, inflammation and disease models.
What is the reaction catalyzed by peroxidase?
The reaction is: a reduced substrate + ROOH = an oxidized substrate + ROH + H2O, meaning a hydroperoxide is reduced while a donor substrate is oxidized.
Conclusion
GO:0004601 peroxidase activity describes a fundamental redox reaction that removes hydroperoxides while oxidizing a donor substrate. It covers classical heme peroxidases such as MPO, EPX, LPO and TPO, non-heme peroxidases such as the PRDX and GPX families, and even engineered nanozymes and metal-organic frameworks with peroxidase-like activity. Because this activity sits at the crossroads of antioxidant defense, inflammation, immunity and disease, it is a productive target for CRISPR-based functional studies. EDITGENE supports these studies with knockout, point-mutation, knock-in, overexpression and library screening services tailored to peroxidase biology.
References
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- 2. Vlasova II. 2018. Peroxidase Activity of Human Hemoproteins: Keeping the Fire under Control.. Molecules 23(10) PMID: 30297621
- 3. Liu C et al.. 2024. Carbon dot enhanced peroxidase-like activity of platinum nanozymes.. Nanoscale 16(9):4637-4646 PMID: 38314787
- 4. Zhang Y et al.. 2025. Metal-Organic Frameworks Nanocomposite Enzymes with Peroxidase-like Activity: Can They Bring Us a New Perspective in the Field of Biological Applications?. ACS Biomater Sci Eng 11(8):4621-4652 PMID: 40702723
- 5. Wei J et al.. 2022. Metal-organic frameworks with peroxidase-like activity for efficient removal of aflatoxin B(1).. Food Chem 378:132037 PMID: 35045371
- 6. Mei W et al.. 2023. DNA-Encoded Bidirectional Regulation of the Peroxidase Activity of Pt Nanozymes for Bioanalysis.. Anal Chem 95(30):11391-11398 PMID: 37459119
- 7. Xu L et al.. 2022. Accelerating the peroxidase-like activity of Co(2+) by quinaldic acid: Mechanism and its analytical applications.. Talanta 239:123080 PMID: 34809983
- 8. da Silva FG et al.. 2022. Achieving enhanced peroxidase-like activity in multimetallic nanorattles.. Dalton Trans 51(39):15133-15141 PMID: 36129247
