NAD+ vs NMN: the coenzyme and the nucleotide it is built from
NAD+ (nicotinamide adenine dinucleotide) and NMN (nicotinamide mononucleotide) are separate molecules: NAD+ is a dinucleotide, and NMN is a single nucleotide that cells convert into it.[1],[2],[3]
One enzyme step connects them: NMN adenylyltransferase (NMNAT) joins NMN to the adenylyl part of ATP, releasing pyrophosphate and leaving NAD+.[3]
This page compares the two by structure and by their places on that biosynthetic route, and it reports no study result for either.[4],[5]
Identity side by side
| Attribute | NAD+ | NMN |
|---|---|---|
| Full name[1],[2] | Nicotinamide adenine dinucleotide | Nicotinamide mononucleotide (also recorded as nicotinamide ribotide) |
| Kind of molecule[1],[2] | Dinucleotide coenzyme | Mononucleotide: a nicotinamide ring on ribose 5′-phosphate |
| Molecular formula[1],[2] | C21H27N7O14P2 | C11H15N2O8P |
| CAS Registry Number[1],[2] | 53-84-9 | 1094-61-7 |
| Enzyme that forms it (salvage route)[3],[4] | NMN adenylyltransferase (NMNAT), from NMN and ATP | Nicotinamide phosphoribosyltransferase (NAMPT), from nicotinamide and PRPP |
| Role in the NMNAT reaction[3] | Product, with pyrophosphate | Substrate, with ATP |
| Where the forming enzyme sits in human cells[5],[4] | NMNAT1 nucleus; NMNAT2 Golgi complex; NMNAT3 mitochondria | NAMPT described as a cytosolic enzyme (mouse) |
| Profile in this library[1] | Yes | No |
How do the two structures relate?
PubChem records NMN under CID 14180 as a 3-carbamoylpyridinium ring bonded to a β-D-ribofuranose that bears a single 5′-phosphate.[2]
NAD+ has the formula C21H27N7O14P2, with two phosphorus atoms to NMN's one and an adenine-bearing half that NMN lacks.[1],[2]
The reaction written in the 2002 structure paper, NMN + ATP = NAD + PPi, accounts for that difference: the adenylyl portion of ATP is added to NMN.[3]
Where does each sit on the biosynthetic route?
Nicotinamide phosphoribosyltransferase condenses nicotinamide with 5-phosphoribosyl-1-pyrophosphate to give NMN, which a 2002 study of the murine enzyme calls an intermediate in NAD biosynthesis.[4]
NMNAT then turns NMN into NAD+, and a 2005 study located its three human isoforms in the nucleus (NMNAT1), the Golgi complex (NMNAT2) and the mitochondria (NMNAT3).[5],[3]
The same study found that NMNAT2 and NMNAT3 can also make NADH directly from reduced NMN, whereas NMNAT1 favours NAD+ synthesis.[5]
In mouse fibroblasts the NAMPT step, not the NMNAT step, limited the rate of this route: adding NAMPT raised total cellular NAD, and adding NMNAT did not.[6]
For NAD+ itself, one cell-culture study read a rise in intracellular NAD after NAD was added to the medium as uptake of the whole dinucleotide, because no precursors were detected in that medium.[7]
What does this comparison leave out?
NMN has no profile in this library, and studies in which people received either molecule fall outside the identity and pathway scope of this page.[1]
Purified-enzyme and cell-culture work shows that the NMN-to-NAD+ step exists; it does not measure how much NMN from outside a cell ends up as NAD+ in a living organism.[3],[6]
Limitations
The NMN identifiers come from a database record, not a registry monograph, and like the NAD+ figures they describe a reference substance rather than any lot.[2],[1]
Enzyme locations and rate findings here come from recombinant human enzymes and mouse fibroblasts, laboratory systems that establish no effect in a person.[5],[6]
Compound profiles
References
- NAD+ research profile, PepGenex Science (identity and records, with their sources).
- National Center for Biotechnology Information, PubChem Compound record for nicotinamide mononucleotide (CID 14180). PubChem CID 14180 · CAS 1094-61-7
- Garavaglia S, D'Angelo I, Emanuelli M, et al. Structure of human NMN adenylyltransferase. A key nuclear enzyme for NAD homeostasis. J Biol Chem. 2002;277(10):8524-8530. PMID 11751893 · DOI 10.1074/jbc.M111589200
- Rongvaux A, Shea RJ, Mulks MH, et al. Pre-B-cell colony-enhancing factor, whose expression is up-regulated in activated lymphocytes, is a nicotinamide phosphoribosyltransferase, a cytosolic enzyme involved in NAD biosynthesis. Eur J Immunol. 2002;32(11):3225-3234. PMID 12555668 · DOI 10.1002/1521-4141(200211)32:11<3225::AID-IMMU3225>3.0.CO;2-L
- Berger F, Lau C, Dahlmann M, Ziegler M. Subcellular compartmentation and differential catalytic properties of the three human nicotinamide mononucleotide adenylyltransferase isoforms. J Biol Chem. 2005;280(43):36334-36341. PMID 16118205 · DOI 10.1074/jbc.M508660200
- Revollo JR, Grimm AA, Imai S. The NAD biosynthesis pathway mediated by nicotinamide phosphoribosyltransferase regulates Sir2 activity in mammalian cells. J Biol Chem. 2004;279(49):50754-50763. PMID 15381699 · DOI 10.1074/jbc.M408388200
- Pittelli M, Felici R, Pitozzi V, Giovannelli L, Bigagli E, Cialdai F, Romano G, Moroni F, Chiarugi A. Pharmacological effects of exogenous NAD on mitochondrial bioenergetics, DNA repair, and apoptosis.. Molecular Pharmacology 2011. PMID 21917911 · DOI 10.1124/mol.111.073916