Purification of membrane-bound aminopeptidase from rat brain: identification of aminopeptidase M.

Two different membrane-bound aminopeptidases were isolated from rat brain membranes, one with a puromycin sensitive activity and the other, not affected by 10 microM puromycin. The physicochemical, catalytic and immunological properties of the latter were compared to those of aminopeptidase M purified from rat kidney membranes and allowed us to conclude to large similarities between these two enzymes. Because the two brain aminopeptidases were both sensitive to bestatin, it remains to be established whether both or only aminopeptidase M is involved in endogenous enkephalin inactivation.