NADPH oxidase H202-forming activity
Definition
Target type: molecularfunction
Catalysis of the reaction: NADPH + H+ + O2 = NADP + hydrogen peroxide (H2O2). [RHEA:11260]
NADPH oxidase H2O2-forming activity is a critical enzymatic process that generates reactive oxygen species (ROS), specifically hydrogen peroxide (H2O2), within cells. This activity is catalyzed by NADPH oxidase enzymes, which are multi-subunit complexes found in various cell types.
The molecular function of NADPH oxidase H2O2-forming activity involves a series of intricate steps:
1. **Electron Transfer:** The enzyme utilizes NADPH as an electron donor, transferring electrons from NADPH to molecular oxygen (O2). This transfer occurs through a series of redox reactions involving various cofactors and protein subunits within the NADPH oxidase complex.
2. **Superoxide Radical Formation:** The transferred electrons reduce O2 to superoxide radicals (O2-), which are highly reactive and unstable molecules.
3. **Dismutation to Hydrogen Peroxide:** Superoxide radicals undergo dismutation, a chemical reaction where two superoxide radicals react with each other, generating hydrogen peroxide (H2O2) and molecular oxygen.
4. **H2O2 Release:** The generated H2O2 is then released from the enzyme and diffuses into the surrounding cellular environment.
NADPH oxidase H2O2-forming activity plays a crucial role in various physiological processes, including:
- **Immune Response:** H2O2 acts as a signaling molecule in immune cells, activating various defense mechanisms against pathogens and other harmful agents.
- **Cell Signaling:** H2O2 is involved in various intracellular signaling pathways, regulating cell growth, differentiation, and apoptosis.
- **Vascular Function:** H2O2 contributes to vascular tone regulation and blood pressure homeostasis.
- **Oxidative Stress Regulation:** While H2O2 is essential in small amounts, excessive production can lead to oxidative stress, damaging cellular components and contributing to various diseases.
Overall, NADPH oxidase H2O2-forming activity is a complex enzymatic process that plays a multifaceted role in maintaining cellular homeostasis and contributing to various physiological functions. Understanding the molecular mechanism of this activity is essential for developing strategies to regulate ROS production and address related pathologies.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| NADPH oxidase 4 | An NADPH oxidase 4 that is encoded in the genome of human. [PRO:WCB, UniProtKB:Q9NPH5] | Homo sapiens (human) |
Compounds (8)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 2-hydroxy-5-(2,5-dihydrobenzyl)aminobenzoic acid | aromatic amine | ||
| staurosporine | indolocarbazole alkaloid; organic heterooctacyclic compound | apoptosis inducer; bacterial metabolite; EC 2.7.11.13 (protein kinase C) inhibitor; geroprotector | |
| quercetin | 7-hydroxyflavonol; pentahydroxyflavone | antibacterial agent; antineoplastic agent; antioxidant; Aurora kinase inhibitor; chelator; EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor; geroprotector; phytoestrogen; plant metabolite; protein kinase inhibitor; radical scavenger | |
| 3,7-dimethoxy-5,3',4'-trihydroxyflavone | 3,7-dimethoxy-5,3',4'-trihydroxyflavone: isolated from Veronia eremophila; structure given in first source 3',4',5-trihydroxy-3,7-dimethoxyflavone : A dimethoxyflavone that the 3,7-di-O-methyl derivative of quercetin. | dimethoxyflavone; trihydroxyflavone | EC 1.3.1.22 [3-oxo-5alpha-steroid 4-dehydrogenase (NADP(+))] inhibitor; metabolite |
| apigenin | Chamomile: Common name for several daisy-like plants (MATRICARIA; TRIPLEUROSPERMUM; ANTHEMIS; CHAMAEMELUM) native to Europe and Western Asia, now naturalized in the United States and Australia. | trihydroxyflavone | antineoplastic agent; metabolite |
| luteolin | 3'-hydroxyflavonoid; tetrahydroxyflavone | angiogenesis inhibitor; anti-inflammatory agent; antineoplastic agent; apoptosis inducer; c-Jun N-terminal kinase inhibitor; EC 2.3.1.85 (fatty acid synthase) inhibitor; immunomodulator; nephroprotective agent; plant metabolite; radical scavenger; vascular endothelial growth factor receptor antagonist | |
| kaempferol | 7-hydroxyflavonol; flavonols; tetrahydroxyflavone | antibacterial agent; geroprotector; human blood serum metabolite; human urinary metabolite; human xenobiotic metabolite; plant metabolite | |
| azaleatin | azaleatin : A monomethoxyflavone that is quercetin in which the hydroxy group at position 5 is replaced by a methoxy group. | 7-hydroxyflavonol; monomethoxyflavone; tetrahydroxyflavone | plant metabolite |