Metalloendopeptidase activity in urine of rodents.

The brush border membrane of mice and rats contains a phosphoramidon-insensitive metalloproteinase, meprin (neutral endopeptidase-2; NEP-2). The role of meprin is unknown, but we have shown that urine from these species contains insulin B chain degrading activity that is due to a phosphoramidon-insensitive metalloendopeptidase. By enzymic and immunological criteria, it is likely that this activity is due to meprin, and introduces the possibility that this enzyme may have a role in urinary function.