What Is NAD+? The Coenzyme, Its Chemistry and the Published Research
NAD+ is not a peptide. It is a small dinucleotide coenzyme found in every living cell. This primer explains what it is, the two roles the literature describes for it, how cells make and consume it, and what that means for the bench.
General laboratory-science education. Not medical advice. Sealed Peptides materials are for in-vitro and laboratory research use only, and are not for human or veterinary use.
What NAD+ is
Nicotinamide adenine dinucleotide, written NAD+ in its oxidized form, is a coenzyme found in all living cells.[1] It is a dinucleotide: two nucleotides joined through their phosphate groups, one carrying adenine and the other nicotinamide. The Sealed Peptides product lists the formula C21H27N7O14P2 and a molecular weight of 663.4 Da, and the average mass calculated from the formula is 663.43 g/mol, in agreement.
Because it is a small molecule and not a chain of amino acids, much of what applies to research peptides does not apply to it. There is no amino acid sequence, no peptide-bond chemistry and no net peptide content in the peptide sense. Calculators that depend on a sequence, such as the peptide molecular weight estimator, are not the right tools; the molarity calculator is, because it only needs the molecular weight.
Two roles in the literature
Reviews describe NAD+ in two distinct roles. In the first it is a coenzyme for redox reactions: it carries electrons from one reaction to another, which makes it central to energy metabolism.[1, 2] In the second it is a cosubstrate for other enzymes, such as the sirtuins and PARPs.[1]
The best-known consumers are the sirtuins, the poly(ADP-ribose) polymerases (PARPs) and CD38.[2] Sirtuins are a family of NAD+-dependent protein deacetylases found across all phyla of life,[3] and the review literature links NAD+-dependent enzymes to processes such as DNA repair, chromatin remodelling, cellular senescence and immune cell function.[2] The common thread is chemical: for these enzymes NAD+ is a consumed reagent,[4] so the amount available matters.
How cells make it, and how it is consumed
Cells keep NAD+ available through biosynthesis and through salvage of the nicotinamide that consuming enzymes release. The enzyme nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the first step of the nicotinamide salvage route, forming nicotinamide mononucleotide, and it is described as the mechanism that replenishes the NAD pool in human metabolism.[5]
A review of the balance between biosynthesis and consumption lists PARPs, SARM1, sirtuins and CD38 as the consumers, and describes reported declines in NAD+ levels during ageing in several organisms as an imbalance between the two sides, with reduced NAMPT and increased activation of PARPs and CD38 as the proposed explanation.[4] The same review literature notes that much remains to be learnt about how NAD+ influences biology in humans and whether altering its levels is beneficial.[2]
What that literature cannot tell you
The reviews cited here concern cellular biochemistry and, in places, the possibility of intervening in it. This page deliberately does not follow them into that territory. Sealed Peptides supplies NAD+ as a laboratory research material, and nothing here describes or endorses any use of it outside a laboratory. A coenzyme being important to cells does not tell you anything about adding the isolated compound to any system, and reviews that raise the prospect of such intervention say themselves that the evidence is incomplete.[2]
The NAD+ research overview lists the cited literature in the same descriptive way.
NAD+ is not NADH, and not its precursors
Several related names are easy to confuse. NAD+ is the oxidized form named in this guide; its reduced partner, NADH, differs by two hydrogen atoms and so has a slightly higher mass (about 665.4 g/mol from its formula, C21H29N7O14P2). Nicotinamide mononucleotide, which NAMPT forms from nicotinamide during salvage,[5] is a smaller molecule that is one of the building blocks of the dinucleotide. They are separate compounds with separate masses, and a mass spectrum that matches one will not match another.
The expected signal for NAD+ can be worked out from its formula in the same way as for a peptide. The monoisotopic mass is 663.109, so a singly protonated ion would appear near m/z 664.12. The label mass of a powder, like that of a peptide, is a gross mass unless documentation states a content, so the amount of NAD+ in a weighed portion is a separate question from the identity of the compound. For example, if the whole of a 500 mg vial were NAD+, it would contain 500 ÷ 663.4 = 0.754 mmol.
Notes for the bench
Solutions are made with the arithmetic in reconstitution math: mass divided by volume gives mg/mL, and dividing by 663.4 g/mol gives molarity. A solution at 6.634 mg/mL, for example, is 10 mM. NAD+ is listed in sizes of 500 and 1000 mg, far larger than a typical peptide vial, so the arithmetic involves larger masses and volumes than most peptide work.
Like other freeze-dried materials, NAD+ is supplied dry. The principles in why materials are freeze-dried apply to why that form is chosen, and the storage guide sets out the general chemistry of degradation. Whether a particular solution of NAD+ is stable for the length of a given experiment is something to test, and a record of storage conditions and freeze-thaw history, kept on the printable log, is what makes the test interpretable.
Terms used in this guide
Related tools and guides
References
- Verdin E. NAD⁺ in aging, metabolism, and neurodegeneration. Science. 2015;350(6265):1208-13. PMID 26785480 · DOI
- Covarrubias AJ, Perrone R, Grozio A, Verdin E. NAD(+) metabolism and its roles in cellular processes during ageing. Nat Rev Mol Cell Biol. 2021;22(2):119-141. PMID 33353981 · DOI
- Sauve AA, Wolberger C, Schramm VL, Boeke JD. The biochemistry of sirtuins. Annu Rev Biochem. 2006;75:435-65. PMID 16756498 · DOI
- Strømland Ø, Diab J, Ferrario E, Sverkeli LJ, Ziegler M. The balance between NAD(+) biosynthesis and consumption in ageing. Mech Ageing Dev. 2021;199:111569. PMID 34509469 · DOI
- Burgos ES. NAMPT in regulated NAD biosynthesis and its pivotal role in human metabolism. Curr Med Chem. 2011;18(13):1947-61. PMID 21517777 · DOI
Cited literature is provided for scientific context only. Many of these reviews concern proteins or pharmaceutical development; they are cited for general chemistry and do not describe or endorse any use of these products.
For laboratory research use only. Not for human or veterinary use. This page is general chemistry education and does not describe or endorse any use of Sealed Peptides products. Cited literature is provided for scientific context only.