Category: nucleotide
Aliases: Nicotinamide adenine dinucleotide, Oxidized NAD
Central redox cofactor for all dehydrogenases: gains a hydride from substrate (NAD⁺ → NADH), donates it to the electron-transport chain (Complex I). Also the substrate for sirtuins (SIRT1-7, deacetylases that cleave NAD⁺), PARPs (DNA-damage response), and CD38/CD157 (immune-cell NADases). NAD⁺ declines ~50% by age 60 — hence the longevity research interest in precursors.