In enzymology, saccharopine dehydrogenase (NADP+, L-lysine-forming) () is an enzyme that catalyzes the chemical reaction
The three substrates of this enzyme are saccharopine, oxidised nicotinamide adenine dinucleotide phosphate (NADP<sup>+</sup>), and water. Its products are L-lysine, ñ-ketoglutaric acid, reduced NADPH, and a proton.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is N6-(L-1,3-dicarboxypropyl)-L-lysine:NADP+ oxidoreductase (L-lysine-forming). Other names in common use include lysine-2-oxoglutarate reductase, lysine-ketoglutarate reductase, L-lysine-alpha-ketoglutarate reductase, lysine:alpha-ketoglutarate:TPNH oxidoreductase, (epsilon-N-[gultaryl-2]-L-lysine forming), saccharopine (nicotinamide adenine dinucleotide phosphate,, lysine-forming) dehydrogenase, 6-N-(L-1,3-dicarboxypropyl)-L-lysine:NADP+ oxidoreductase, and (L-lysine-forming). This enzyme participates in lysine biosynthesis and lysine degradation.