Metalloprotease which may be important for placentation by regulating biological activity of key peptides at the embryo-maternal interface. On synthetic substrates it shows a marked preference for Leu-4-methylcoumaryl-7-amide (Leu-MCA) over Met-MCA, Arg-LCA and Lys-LCA. Cleaves the N-terminal amino acid of several peptides such as angiotensin-3, kisspeptin-10 and endokinin C. Binds 1 zinc ion per subunit. Inhibited by bestatin. Optimum pH is 7.0. Homodimer. Specifically expressed in placenta and not in other tissues. Mainly found at the cell surface region of the extravillous trophoblasts. Detected on extravillous trophoblasts in the outer layer of the chorion laeve in the fetal membrane Not detected on either fetal amnionic epithelial cells or maternal decidual cells. Also detected in the migrating extravillous trophoblasts in the maternal decidual tissues (at protein level). N-glycosylated. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the peptidase M1 family. Extended N-terminus.