Nicotinamide adenine dinucleotide, NAD+ and NADH (pyridine nucleotide coenzymes, NAD and NADP), is an oxidation-reduction coenzyme (redox cofactor; compare FADH2). In the NADH electron transfer-pathway state fuelled by type N substrates, mt-matrix dehydrogenases generate NADH, the substrate of Complex I (CI). The mt-NADH pool integrates the activity of the TCA cycle and various matrix dehydrogenases upstream of CI, and thus forms a junction or funnel of electron transfer to CI, the N-junction (compare F-junction, Q-junction). NAD+ and NADH are not permeable through the mt-inner membrane, mtIM. Cytosolic NADH is effectively made available for mitochondrial respiration through the malate-aspartate shuttle or glycerophosphate dehydrogenase Complex.
Communicated by Gnaiger E 2016-02-12, last edit 2019-07-01.
Application in HRR
- Nicotinadeninedinucleotide, NADH (β-Nicotinamide adenine dinucleotide, reduced potassium salt, C21H27N7O14P2K2); Sigma A 4505, 100 mg, store at -20 °C (old Sigma recommendation: 4-8 °C); FW = 742.61, for important considerations concerning storage of NADH (powder and solutions) and preparation of solutions see the product information from Sigma: . The same precautions are recommended by Sigma for the sodium salt.
- DPN+ = NAD+
- DPNH, reduced diphosphopyridine nucleotide = NADH
- TPN+ = NADP+
- TPNH, reduced triphosphopyridine nucleotide = NADPH
MitoPedia topics: Substrate and metabolite