Hydrolyzes a wide range of dipeptides including the conversion of leukotriene D4 to leukotriene E4 (PubMed:12738806, PubMed:31442408, PubMed:9560193). Hydrolyzes cystinyl-bis-glycine (cys-bis-gly) formed during glutathione degradation (PubMed:12738806, PubMed:9560193). Possesses also beta lactamase activity and hydrolytically inactivates beta-lactam antibiotics (PubMed:12738806). 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 2 H2O + L-cystine-bis-glycine = 2 glycine + L-cystine a beta-lactam + H2O = a substituted beta-amino acid glycyldehydrophenylalanine + H2O = 2,3-didehydrophenylalanine + glycine Inhibited by L-penicillamine. Inhibited by cilastatin. Homodimer; disulfide-linked. Brush border membrane. Expressed in heart, lung, skeletal muscle, kidney, liver, and testis. Not detected in brain and spleen. Deficient mice are phenotypically normal. However deficient mice display a partial loss in the conversion of leukotriene D4 to leukotrience E4 and in the conversion of cys-bis-gly to cysteine and glycine (PubMed:9560193). Deficient mice display reduces mortality in models of sepsis (PubMed:31442408). Belongs to the metallo-dependent hydrolases superfamily. Peptidase M19 family.