Immunological characterisation of different meprin species in mice.

Meprin-a is a metalloendopeptidase present at high levels in the kidney brush border of some inbred mouse strains. Meprin-b is a latent metallo-endopeptidase, activated by trypsin-mediated proteolysis in vitro, that is present at similar activities (after activation) in all mouse strains. Meprin (a mixture of a and b forms) was purified from a high-meprin Mep-1a/a animal, and Lys-C peptides of this preparation were sequenced. The sequence data were used to direct the synthesis of peptides that were conjugated to albumin and used as immunogens. One of these antisera was specific to meprin-b and thus provided a specific tool to monitor expression of this form of meprin in different mouse strains.