In enzymology, a 1-pyrroline-4-hydroxy-2-carboxylate deaminase () is an enzyme that catalyzes the chemical reaction 1-pyrroline-4-hydroxy-2-carboxylate + H2O 2,5-dioxopentanoate + NH3 Thus, the two substrates of this enzyme are 1-pyrroline-4-hydroxy-2-carboxylate and H2O, whereas its two products are 2,5-dioxopentanoate and NH3. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amidines. The systematic name of this enzyme class is 1-pyrroline-4-hydroxy-2-carboxylate aminohydrolase (decyclizing). This enzyme is also called HPC deaminase. This enzyme participates in arginine and proline metabolism. References EC 3.5.4 Enzymes of unknown structure