Pterin deaminase

In enzymology, a pterin deaminase (EC 3.5.4.11) is an enzyme that catalyzes the chemical reaction

Thus, the two substrates of this enzyme are 2-amino-4-hydroxypteridine and H₂O, whereas its two products are 2,4-dihydroxypteridine 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 2-amino-4-hydroxypteridine aminohydrolase. This enzyme is also called acrasinase.