NADPH is the reduced form of the electron acceptor nicotinamide adenine dinucleotide phosphate (NADP+) and acts as an electron donor in various biological reactions. In plants, NADPH is produced by ferredoxin-NADP+ reductase in the last step of the electron chain during photosynthesis. In animals it is predominantly produced by the pentose phosphate pathway, but it is also generated by key mitochondrial enzymes. NADPH provides the reducing equivalents for biosynthetic reactions and the oxidation-reduction involved in protecting against the toxicity of reactive oxygen species.1,2,3 It is also used for the synthesis of lipids and cholesterol and during the process of fatty acid chain elongation.4
1.Sumimoto, H.Structure, regulation and evolution of Nox-family NADPH oxidases that produce reactive oxygen speciesFEBS J.275(13)3249-3277(2008) 2.Sutherland, M.W., Nelson, J., Harrison, G., et al.Effects of t-butyl hydroperoxide on NADPH, glutathione, and the respiratory burst of rat alveolar machrophagesArch. Biochem. Biophys.243(2)325-331(1985) 3.Nauseef, W.M.Biological roles for the NOX family NADPH oxidasesJ. Biol. Chem.283(25)16961-16965(2008) 4.Tserng, K.Y., and Jin, S.J.NADPH-dependent reductive metabolism of cis-5 unsaturated fatty acids. A revised pathway for the β-oxidation of oleic acidJ. Biol. Chem.266(18)11614-11620(1990)