| Description | β-Nicotinamide adenine dinucleotide (NAD+) and β-Nicotinamide adenine dinucleotide, reduced (NADH) comprise a coenzyme redox pair (NAD+:NADH) involved in a wide range of enzyme catalyzed oxidation reduction reactions. In addition to its redox function, NAD+/NADH is a donor of ADP-ribose units in ADP-ribosylaton (ADP-ribosyltransferases; poly(ADP-ribose) polymerases ) reactions and a precursor of cyclic ADP-ribose (ADP-ribosyl cyclases). |
| Chemical Properties | White to beige powder |
| Uses | One of the biologically active forms of nicotinic acid. Serves as a coenzyme of hydrogenases and dehydrogenases. NAD usually acts as a hydrogen acceptor, forming NADH which then serves as a hydrogen donor in the respiratory chain. Present in living cells primarily in the reduced form (NADPH) and is involved in synthetic reactions. Occurs in 2 forms, α-NAD and β-NAD, distinguished by the configuration of the ribosyl nicotinamide linkage. Only the β-anomer is bioactive. |
| Uses | β-Nicotinamide adenine dinucleotide, reduced disodium salt has been used in the preparation of standard curve. |
| Definition | NADH, disodium salt is a dehydrogenase complex that is the reduced formof NAD. As a reagent, NADH can be used in enzyme cycling assays to amplify detection of activity of biologically relevant enzymes or metabolites present in low concentrations. |
| Biological Functions | NADH disodium salt (Disodium NADH) is an orally active reduced coenzyme. NADH disodium salt is a donor of ADP-ribose units in ADP-ribosylaton reactions and a precursor of cyclic ADP-ribose. NADH disodium salt plays a role as a regenerative electron donor in cellular energy metabolism, including glycolysis, β-oxidation and the tricarboxylic acid (TCA) cycle. |
| General Description | β-Nicotinamide adenine dinucleotide (β-NAD) regulates energy metabolism and immunity. It is a cofactor for mitochondrial deacetylase sirtuin-3 enzyme and modulates inflammasome assembly. β-NAD supresses interleukin-1β levels in monocytic cells in inflammatory syndromes. β-NAD released by neurosecretory cells is a potential neurotransmitter. β-NAD is a vascular mediator in lung endothelial cells and may play a protective role against cytokine mediated inflammation. |
| Biochem/physiol Actions | NADH is a coenzyme that functions as a regenerating electron donor in catabolic processes including glycolysis, β-oxidation and the citric acid cycle (Krebs cycle, TCA cycle). It participates in cell signaling events as well, for example as a substrate for the poly (ADP-ribose) polymerases (PARPs) during the DNA damage response. The NAD+/NADH dependent sirtuins play key roles in stress responses during events involving energy metabolism, with implications in cancer biology, diabetes and neurodegenerative disease. |
| Biotechnological Applications | Reduced β-nicotinamide adenine dinucleotide (NADH) plays a major role in metabolism as a cofactor in redox reactions and as a mobile electron carrier. NADH is a high energy compound that donates electrons to the electron transport chain to provide energy for ATP production by oxidative phosphorylation. NADH is a required oxidizing cosubstrate in fermentation, which regenerates NAD. NADH is fluorescent, which provides for a relatively simple way to detect NADH in biological samples. NADH is also used in enzyme cycling assays to detect relevant biological molecules in tissues. |
| Purification Methods | This coenzyme is available in high purity, and it is advisable to buy a fresh preparation rather than to purify an old sample as purification will invariably lead to a more impure sample contaminated with the oxidised form (NAD). It has UV max at 340nm ( 6,200 M-1cm-1) at which wavelength the oxidised form NAD has no absorption. At 340nm a 0.161mM solution in a 1cm (pathlength) cell has an absorbance of 1.0 unit. The purity is best checked by the ratio A280nm/A340nm ~2.1, a value which increases as oxidation proceeds. The dry powder is stable indefinitely at -20o. Solutions in aqueous buffers at pH ~7 are stable for extended periods at -20o and for at least 8hours at 0o, but are oxidised more rapidly at 4o in a cold room (e.g. almost completely oxidised overnight at 4o). [UV: Drabkin J Biol Chem 175 563 1945, Fluorescence: Boyer & Thorell Acta Chem Scand 10 447 1956, Redox: Rodkey J Biol Chem 234 188 1959, Schlenk in The Enzymes 2 250, 268 1951, Kaplan in The Enzymes 3 105, 112 1960.] Deuterated NADH, i.e. NADD, has been purified through the anion exchange resin AG-1 x 8 (100-200 mesh, formate form) and through a Bio-Gel P-2 column. [Viola et al. Anal Biochem 96 334 1979, Beilstein 26 III/IV 3639.] |
