In enzymology, a diguanidinobutanase () is an enzyme that catalyzes the chemical reaction 1,4-diguanidinobutane + H2O agmatine + urea Thus, the two substrates of this enzyme are 1,4-diguanidinobutane and H2O, whereas its two products are agmatine and urea. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amidines. The systematic name of this enzyme class is 1,4-diguanidinobutane amidinohydrolase. References EC 3.5.3 Enzymes of unknown structure