Hydrolyzes a wide range of dipeptides including the conversion of leukotriene D4 to leukotriene E4 (PubMed:2303490, PubMed:6334084, PubMed:31442408, PubMed:32325220). Hydrolyzes cystinyl-bis-glycine (cys-bis-gly) formed during glutathione degradation (PubMed:32325220). Possesses also beta lactamase activity and can hydrolyze the beta-lactam antibiotic imipenem (PubMed:6334084, PubMed:32325220). Independently of its dipeptidase activity, acts as an adhesion receptor for neutrophil recruitment from bloodstream into inflamed lungs and liver. an L-aminoacyl-L-amino acid + H2O = 2 an L-alpha-amino acid H2O + leukotriene D4 = glycine + leukotriene E4 a beta-lactam + H2O = a substituted beta-amino acid 2 H2O + L-cystine-bis-glycine = 2 glycine + L-cystine glycyldehydrophenylalanine + H2O = 2,3-didehydrophenylalanine + glycine Binds 2 Zn(2+) ion per monomer. Inhibited by L-penicillamine (PubMed:31442408). Beta-lactamase activity is inhibited by cilastatin (PubMed:6334084, PubMed:31442408). Homodimer; disulfide-linked. Brush border membrane. Expressed in lung and kidneys. Up-regulated in n colorectal cancers. Belongs to the metallo-dependent hydrolases superfamily. Peptidase M19 family.