In enzymology, a 1-aminocyclopropane-1-carboxylate deaminase (EC 3.5.99.7) is an enzyme that catalyzes the chemical reaction 1-aminocyclopropane-1-carboxylate + H2O 2-oxobutanoate + NH3 Thus, the two substrates of this enzyme are 1-aminocyclopropane-1-carboxylate and H2O, whereas its two products are 2-oxobutanoate and NH3.