A coenzyme, not a peptide
Nicotinamide adenine dinucleotide is a coenzyme with a molecular mass of 663.4 daltons, supplied as a lyophilised powder. It is the one item in this catalogue that is not a peptide, and that distinction governs almost everything about how it is analysed and handled.
Structurally it is two nucleotides joined through their phosphate groups. One carries adenine, the other carries nicotinamide. There is no peptide bond anywhere in the molecule, so the analytical methods used for the rest of the catalogue do not transfer directly.
It was first described in 1906 by Arthur Harden and William Young, who found that a heat stable, dialysable fraction of yeast juice was required for fermentation to proceed. They called it cozymase. The structure was worked out over the following decades, with Hans von Euler-Chelpin and Otto Warburg among those who contributed to establishing what the molecule is and how it functions.
Its role is to carry electrons. The nicotinamide ring accepts a hydride ion to become the reduced form, usually written NADH, and gives it up again to return to the oxidised form. That cycle underlies a very large number of enzymatic reactions.
Published research context
Nicotinamide adenine dinucleotide appears throughout biochemistry, both as the subject of study and as a reagent. Published research areas include the enzymology of the many oxidoreductases that use it, the biosynthetic and salvage pathways that maintain cellular pools, and its consumption by enzyme families such as the sirtuins and the poly ADP ribose polymerases, which cleave the molecule rather than cycling it.
It is also a standard laboratory reagent. Coupled enzyme assays frequently track the appearance or disappearance of the reduced form by absorbance at 340 nanometres, which is one of the most widely used readouts in enzymology.
The literature is extensive and spans more than a century. This material is supplied for laboratory research only.
How each lot is characterised
Because this is a nucleotide rather than a peptide, the analytical approach differs from the rest of the catalogue. Purity is determined by high performance liquid chromatography, but detection is at 260 nanometres, where the adenine and nicotinamide rings absorb strongly, rather than at the 214 nanometres used for peptide bonds.
The ratio of absorbance at 260 nanometres to absorbance at 340 nanometres is informative, because the oxidised form does not absorb at 340 while the reduced form does. That ratio therefore reports on how much of the material is present as the reduced form, which for a product specified as the oxidised form is a purity attribute.
Identity is confirmed by mass spectrometry against the theoretical mass of 663.4 daltons. The certificate also records appearance, water content and, because this material is hygroscopic, that figure deserves particular attention.
Handling on the bench
Store the unopened vial at minus twenty degrees, dark and desiccated. The powder is hygroscopic, so let the vial reach room temperature fully before opening. Opening a cold vial draws moist air onto cold material, and water taken up this way both degrades the compound and makes any later mass based measurement inaccurate.
Reconstitute with bacteriostatic water added slowly against the vial wall. The compound dissolves readily. Unlike the peptides in this catalogue, aggregation at the air and liquid interface is not the concern here, but pH is. Solutions are most stable slightly acidic, and the compound degrades appreciably faster in alkaline conditions, so preparing in an unbuffered or mildly acidic solution and adding to buffer at the point of use is generally better practice than storing it in an alkaline buffer.
Refrigerate after reconstitution, aliquot for single use and avoid freeze and thaw cycles. Prepare working solutions fresh where the experiment allows, since aqueous solutions are less stable than the dry powder by a wide margin.
Specification
| Form | Lyophilised powder |
|---|---|
| Class | Dinucleotide coenzyme, not a peptide |
| Molecular mass | 663.4 Da |
| Fill size | 500 mg |
| Purity method | HPLC with detection at 260 nm |
| Storage | Minus 20 degrees, dark and desiccated |
References
- Harden A, Young WJ (1906). The alcoholic ferment of yeast-juice. Proceedings of the Royal Society of London B, volume 78.
- Belenky P, Bogan KL, Brenner C (2007). NAD+ metabolism in health and disease. Trends in Biochemical Sciences, volume 32.
For research use only
Products are supplied for laboratory research by qualified researchers and institutions. They are not for human or veterinary use, not for diagnostic or therapeutic use, and are not drugs, foods or cosmetics.