Meprins are multidomain zinc metalloproteases that are highly expressed in mammalian kidney and intestinal brush border membranes and in leukocytes and certain cancer cells. Mature meprins are oligomers of evolutionarily related, separately encoded alpha and/or beta subunits. Homooligomers of meprin-alpha are secreted; oligomers containing meprin-beta are associated with the plasma membrane. Substrates include bioactive peptides and extracellular matrix proteins.