In enzymology, pyrroline-2-carboxylate reductase () is an enzyme that catalyzes the chemical reaction
The three substrates of this enzyme are 1-pyrroline-2-carboxylic acid, reduced nicotinamide adenine dinucleotide (NADH), and a proton. Its products are L-proline and oxidised (NAD<sup>+</sup>). Nicotinamide adenine dinucleotide phosphate can be used as an alternative cofactor. The equivalent 6-membered nitrogen containing ring is also reduced, giving L-pipecolic acid.
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 L-proline:NAD(P)+ 2-oxidoreductase. This enzyme is also called Delta1-pyrroline-2-carboxylate reductase. This enzyme participates in lysine degradation and arginine and proline metabolism.