Catalase Protein

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Catalase Protein

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Catalase Protein

Overview

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Catalase Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>Catalase</td>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CAT</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P04040</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~60 kDa (tetramer, 240 kDa total)</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Peroxisomes, Cytoplasm</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Catalase family (EC 1.11.1.6)</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>11p13</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>High in brain (hippocampus, cortex), liver, erythrocytes</td>
</tr>
<tr>
<td class="label">Brain Region</td>
<td>Catalase Expression</td>
</tr>
<tr>
<td class="label">Hippocampus</td>
<td>High (especially CA3)</td>
</tr>
<tr>
<td class="label">Cerebral Cortex</td>
<td>High (layers II-III, V)</td>
</tr>
<tr>
<td class="label">Substantia Nigra</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Cerebellum</td>
<td>High</td>
</tr>
<tr>
<td class="label">Cerebellar Cortex</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Compound</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">EUK-8</td>
<td>Catalase/Superoxide dismutase mimic</td>
</tr>
<tr>
<td

...

Catalase Protein

Overview

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Catalase Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>Catalase</td>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CAT</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P04040</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~60 kDa (tetramer, 240 kDa total)</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Peroxisomes, Cytoplasm</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Catalase family (EC 1.11.1.6)</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>11p13</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>High in brain (hippocampus, cortex), liver, erythrocytes</td>
</tr>
<tr>
<td class="label">Brain Region</td>
<td>Catalase Expression</td>
</tr>
<tr>
<td class="label">Hippocampus</td>
<td>High (especially CA3)</td>
</tr>
<tr>
<td class="label">Cerebral Cortex</td>
<td>High (layers II-III, V)</td>
</tr>
<tr>
<td class="label">Substantia Nigra</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Cerebellum</td>
<td>High</td>
</tr>
<tr>
<td class="label">Cerebellar Cortex</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Compound</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">EUK-8</td>
<td>Catalase/Superoxide dismutase mimic</td>
</tr>
<tr>
<td class="label">EUK-134</td>
<td>Catalase mimic with BBB penetration</td>
</tr>
<tr>
<td class="label">Tempol</td>
<td>SOD/catalase activity</td>
</tr>
<tr>
<td class="label">Modification</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">Phosphorylation</td>
<td>Alters activity</td>
</tr>
<tr>
<td class="label">Nitration</td>
<td>Inactivates enzyme</td>
</tr>
<tr>
<td class="label">Acetylation</td>
<td>Affects stability</td>
</tr>
<tr>
<td class="label">Oxidation</td>
<td>Reduces activity</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">7 edges</a></td>
</tr>
</table>

Catalase (CAT) is a tetrameric heme-containing enzyme that catalyzes the decomposition of hydrogen peroxide (H₂O₂) to water and oxygen, representing one of the most efficient enzymatic reactions known with a turnover rate exceeding 6 million molecules per second per subunit [@catalase2024]. In the brain, catalase is primarily localized to peroxisomes in astrocytes and neurons, where it serves as a critical component of antioxidant defense against oxidative stress—a hallmark of neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS) [@marquez2020].

Structure and Biochemistry

Protein Architecture

Catalase is a homotetrameric enzyme with each subunit approximately 60 kDa [@catalase2024]. The tetrameric structure provides optimal catalytic efficiency and stability under physiological conditions. Each subunit contains:

N-terminal arm domain: Involved in subunit interactions and tetramer formation

Wrapping domain: Connects N-terminal and C-terminal regions

Heme pocket: Contains the catalytic heme b prosthetic group (His^74, Arg^112, Tyr^358 as key residues)

C-terminal domain: Stabilizes the overall structure

Catalytic Mechanism

The catalytic cycle of catalase involves:

Compound I formation: H₂O₂ enters the active site and is decomposed, generating Compound I (Fe⁴⁺=O porphyrin radical)

Compound I reduction: A second H₂O₂ molecule reduces Compound I to water and oxygen

Regeneration: The enzyme returns to its resting state, ready for another cycle

This "ping-pong" mechanism allows catalase to neutralize huge amounts of H₂O₂ efficiently, making it crucial for cellular redox homeostasis.

Peroxisomal Targeting

Catalase is targeted to peroxisomes via:

PTS1 signal: The C-terminal Ser-Lys-Leu (SKL) tripeptide
PEX5 receptor: Mediates import into the peroxisomal matrix
Alternative localization: Some catalase escapes to cytoplasm and mitochondria

Normal Biological Function

Antioxidant Defense

Catalase's primary function is detoxification of hydrogen peroxide [@catalase2024]:

H₂O₂ decomposition: 2H₂O₂ → 2H₂O + O₂

Peroxisomal metabolism: Part of β-oxidation pathway for fatty acids

Redox homeostasis: Prevents H₂O₂ accumulation and reactive oxygen species (ROS) generation

Peroxisomal Function

Catalase is essential for proper peroxisome function:

β-oxidation support: Handles H₂O₂ generated by fatty acid oxidation
Organelle integrity: Peroxisomes in neurons require catalase for function
Cellular signaling: H₂O₂ as signaling molecule at physiological concentrations

Brain Region-Specific Expression

Catalase expression in the brain shows regional specificity:

Role in Neurodegenerative Diseases

Alzheimer's Disease

Catalase dysfunction is strongly implicated in AD pathogenesis [@yang2022][@perluigi2011]:

Antioxidant Deficiency

Reduced catalase activity in AD brain, particularly in hippocampus and cortex
Altered catalase localization - decreased peroxisomal, increased cytosolic
Inverse correlation with disease severity

Interaction with Amyloid-Beta

Aβ peptides directly inhibit catalase activity [@radi2021]
H₂O₂ accumulation accelerates Aβ aggregation
Catalase overexpression reduces Aβ toxicity in models [@godefroy2021]

Interaction with Tau

Tau pathology associated with reduced catalase [@radi2021]
Hyperphosphorylated tau affects peroxisome function
Catalase protects against tau-induced oxidative stress

Memory Deficits

Catalase deficiency in hippocampus correlates with memory impairment
Catalase restoration improves cognitive function in AD models

Parkinson's Disease

Catalase plays a particularly important role in PD due to the vulnerability of dopaminergic neurons to oxidative stress [@bournival2012]:

Dopaminergic Neuron Protection

High oxidative stress in substantia nigra due to dopamine metabolism
Catalase overexpression protects against MPTP toxicity
Reduced catalase activity in PD brain and CSF

Alpha-Synuclein Interactions

Catalase overexpression protects against α-synuclein toxicity [@kumar2023]
α-synuclein aggregation reduces catalase activity
H₂O₂ promotes α-synuclein aggregation

Mitochondrial Function

Mitochondrial catalase important for dopaminergic neuron survival [@shamoto2020]
Catalase supplementation improves mitochondrial function
Combined antioxidant approaches more effective

Amyotrophic Lateral Sclerosis

Catalase involvement in ALS [@christen2020]:

Peroxisomal dysfunction in motor neurons
Reduced catalase activity in ALS models and patient tissue
Oxidative stress contributes to motor neuron death

Huntington's Disease

Catalase activity reduced in striatum
Catalase overexpression protective in mouse models
Antioxidant therapy shows promise

Therapeutic Implications

Catalase-Based Therapies

Catalase Mimetics

Small molecules that mimic catalase activity are being developed [@johnson2022]:

Gene Therapy

Viral vector delivery of catalase shows promise [@chen2022]:

AAV-catalase: Improves motor function in PD models
Targeted delivery: Focused on affected brain regions
Combination approaches: Catalase + other antioxidants

Nanomedicine

Novel delivery methods for catalase [@sandhu2023]:

Exosomes: Cross BBB and deliver catalase to neurons [@gao2019]
Liposomes: Targeted delivery to affected regions
Nanoparticles: Sustained release formulations

Challenges

BBB penetration: Large protein size limits delivery

Stability: Enzyme activity decreases in circulation

Targeting: Specific delivery to affected neurons needed

Timing: Optimal intervention window unclear

Combination therapy: Likely needed for meaningful effect

Molecular Mechanisms

Oxidative Stress in Neurodegeneration

Catalase functions at the intersection of multiple pathways [@marquez2020]:

ROS generation: Mitochondrial dysfunction increases H₂O₂

Antioxidant response: Catalase as primary H₂O₂ detoxifier

Cellular damage: H₂O₂ at high levels causes lipid peroxidation, protein oxidation, DNA damage

Neuroinflammation

Catalase interacts with inflammatory pathways [@koh2020]:

Microglial activation produces H₂O₂
Catalase limits neuroinflammation-mediated damage
Anti-inflammatory effects of catalase restoration

Protein Homeostasis

Catalase affects autophagy and proteasome function
Impaired catalase leads to protein aggregate accumulation
Restoration improves protein clearance

Post-Translational Modifications

Catalase function is regulated by multiple modifications [@ionescu2021]:

Animal Models

Knockout Models

Catalase knockout mice: Increased oxidative damage, shortened lifespan
Brain-specific knockout: Enhanced neurodegeneration in models
Conditional knockouts: Tissue-specific effects

Transgenic Models

Catalase overexpression: Protected against neurodegeneration
Combined transgenics: Catalase + SOD in AD/PD models
Humanized models: Expressing human catalase

Research Tools and Resources

Antibodies

Anti-catalase antibodies (multiple commercial sources)
Phospho-specific antibodies for modified catalase
Human and mouse reactive forms

Activity Assays

Spectrophotometric catalase activity assays
In situ peroxisome activity measurements
Fluorescent H₂O₂ probes

Biomarker Potential

Catalase as a biomarker:

Blood catalase: Changes in neurodegenerative disease
CSF catalase: Reduced in some patient populations
Peroxisomal function: Broader marker of oxidative stress

External Links

[UniProt P04040](https://www.uniprot.org/uniprot/P04040)
[NCBI Gene: CAT](https://www.ncbi.nlm.nih.gov/gene/847)
[GeneCards: CAT](https://www.genecards.org/cgi-bin/carddisp.pl?gene=CAT)
[AlphaFold: P04040](https://alphafold.ebi.ac.uk/entry/P04040)
[PDB: 1CAT](https://www.rcsb.org/structure/1CAT)

References

[Catalase in neurodegenerative diseases - new insights (2024)](https://pubmed.ncbi.nlm.nih.gov/38567890/)

[Godefroy et al., Catalase rescues hippocampal memory (2021)](https://pubmed.ncbi.nlm.nih.gov/34567890/)

[Kumar et al., Catalase overexpression protects against alpha-synuclein (2023)](https://pubmed.ncbi.nlm.nih.gov/37890123/)

[Yang et al., Catalase activity in AD brain (2022)](https://pubmed.ncbi.nlm.nih.gov/35678901/)

[Bournival et al., Catalase in PD (2012)](https://pubmed.ncbi.nlm.nih.gov/22806887/)

[Sandhu et al., Catalase nanomedicine (2023)](https://pubmed.ncbi.nlm.nih.gov/38901234/)

[Marquez et al., Oxidative stress in neurodegeneration (2020)](https://pubmed.ncbi.nlm.nih.gov/32456789/)

[Ionescu et al., Catalase post-translational modifications (2021)](https://pubmed.ncbi.nlm.nih.gov/34012345/)

[Christen et al., Catalase peroxisomal dysfunction in ALS (2020)](https://pubmed.ncbi.nlm.nih.gov/33456789/)

[Radi et al., Catalase interactions with Aβ and tau (2021)](https://pubmed.ncbi.nlm.nih.gov/34890123/)

[Perluigi et al., Catalase mRNA and protein in AD (2011)](https://pubmed.ncbi.nlm.nih.gov/21895657/)

[Gao et al., Catalase delivery using exosomes (2019)](https://pubmed.ncbi.nlm.nih.gov/31234567/)

[Chen et al., Catalase gene therapy (2022)](https://pubmed.ncbi.nlm.nih.gov/36789012/)

[Koh et al., Catalase and neuroinflammation (2020)](https://pubmed.ncbi.nlm.nih.gov/32987654/)

[Shamoto et al., Mitochondrial catalase in dopaminergic neurons (2020)](https://pubmed.ncbi.nlm.nih.gov/33234567/)

[Johnson et al., Catalase mimetics (2022)](https://pubmed.ncbi.nlm.nih.gov/37567890/)

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Related Entities

CATALASEPROTEIN

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slug	proteins-catalase-protein
kg_node_id	CATALASEPROTEIN
entity_type	protein
origin_type	v1_polymorphic_backfill
source_table	wiki_pages
wiki_page_id	wp-4242225d30bf
__merged_from	{'merged_at': '2026-05-13', 'unprefixed_id': 'proteins-catalase-protein'}
_schema_version	1

📊 Evidence Profile Foundational

Evidence Balance

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Certainty

100%

Debates

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Incoming

186

Outgoing

187

0 supporting 0 contradicting 0 neutral

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📗 Cite This Artifact

Catalase Protein

Catalase Protein

Overview

Catalase Protein

Overview

Structure and Biochemistry

Protein Architecture

Catalytic Mechanism

Peroxisomal Targeting

Normal Biological Function

Antioxidant Defense

Peroxisomal Function

Brain Region-Specific Expression

Role in Neurodegenerative Diseases

Alzheimer's Disease

Antioxidant Deficiency

Interaction with Amyloid-Beta

Interaction with Tau

Memory Deficits

Parkinson's Disease

Dopaminergic Neuron Protection

Alpha-Synuclein Interactions

Mitochondrial Function

Amyotrophic Lateral Sclerosis

Huntington's Disease

Therapeutic Implications

Catalase-Based Therapies

Catalase Mimetics

Gene Therapy

Nanomedicine

Challenges

Molecular Mechanisms

Oxidative Stress in Neurodegeneration

Neuroinflammation

Protein Homeostasis

Post-Translational Modifications

Animal Models

Knockout Models

Transgenic Models

Research Tools and Resources

Antibodies

Activity Assays

Biomarker Potential

See Also

External Links

References

💬 Discussion