4-oxoproline reductase

In enzymology, 4-oxoproline reductase is an enzyme that catalyzes the chemical reaction
The substrates of this enzyme are cis-4-hydroxyproline, and oxidised nicotinamide adenine dinucleotide. Its products are 4-oxo-L-proline and reduced NADH.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is 4-hydroxy-L-proline:NAD⁺ oxidoreductase. This enzyme is also called hydroxy-L-proline oxidase. This enzyme was originally thought to participate in the metabolism of arginine and proline. However, recent data show that it is unlikely since neither 4-oxo-L-proline nor cis-4-hydroxy-L-proline are metabolites of these metabolic pathways.

Gene

The gene encoding 4-oxo-L-proline reductase was identified as 3-hydroxybutyrate dehydrogenase 2 by Sebastian Kwiatkowski and co-workers in 2022. The enzyme is a member of the Short-chain Dehydrogenases/Reductases (SDR) family of enzymes.