NADH dehydrogenase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: NADH + H+ + acceptor = NAD+ + reduced acceptor. [RHEA:11356]

NADH dehydrogenase activity is a crucial enzymatic process that catalyzes the transfer of electrons from NADH to an electron acceptor, typically ubiquinone (CoQ) or a similar molecule. This transfer is essential for the electron transport chain, a central component of cellular respiration. Here's a detailed breakdown of its molecular function:

1. **Substrate Binding:** NADH dehydrogenase enzymes bind to NADH, the reduced form of nicotinamide adenine dinucleotide, which carries electrons from various metabolic pathways.

2. **Electron Transfer:** The enzyme facilitates the transfer of two electrons from NADH to a specific site within the enzyme, often containing iron-sulfur clusters or flavin mononucleotide (FMN) cofactors.

3. **Redox Reactions:** These electron transfers involve redox reactions, where NADH is oxidized to NAD+, and the electron acceptor is reduced.

4. **Proton Translocation:** In many NADH dehydrogenase enzymes, the electron transfer process is coupled with the translocation of protons across a membrane, contributing to the generation of a proton gradient that drives ATP synthesis.

5. **Energy Conservation:** The energy released during electron transfer is harnessed to drive the translocation of protons, contributing to the energy conservation mechanisms of the cell.

6. **Specificity:** Different NADH dehydrogenase enzymes exhibit varying substrate specificities, with some favoring NADH while others can also act on NADPH.

7. **Regulation:** NADH dehydrogenase activity is tightly regulated to ensure proper energy production and avoid uncontrolled electron transfer.

8. **Biological Significance:** NADH dehydrogenase activity is essential for the production of ATP, the primary energy currency of the cell. It also plays a crucial role in various metabolic pathways, including glycolysis, the citric acid cycle, and fatty acid oxidation.

9. **Clinical Relevance:** Dysregulation of NADH dehydrogenase activity can lead to various diseases, including mitochondrial disorders and cancer.

Overall, NADH dehydrogenase activity is a fundamental enzymatic process that underpins cellular energy production and plays a critical role in maintaining cellular homeostasis.'
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Proteins (9)

Compounds (3)