H2O + L-asparagine = L-aspartate + NH4(+) Heterodimer of an alpha and beta chain produced by autocleavage. This heterodimer may then dimerize in turn, giving rise to a heterotetramer (By similarity). Cleaved into an alpha and beta chain by autocatalysis; this activates the enzyme. The N-terminal residue of the beta subunit is responsible for the nucleophile hydrolase activity (By similarity). Belongs to the Ntn-hydrolase family.