AMINOPEPTIDASE-P - A CELL-SURFACE ANTIGEN OF ENDOTHELIAL AND LYMPHOID-CELLS - CATALYTIC AND IMMUNO-HISTOTOPICAL EVIDENCES

The physiological function of the GPI-anchored ectoenzyme aminopeptida se P (APP) is still elusive, Most researchers suppose that this enzyme inactivates biologically active peptides like bradykinin, neuropeptid e tyrosine (NPY) and others (Vanhoof ef al,, 1995), We demonstrate by immunohistology with a specific antibody raised in rabbits and measure ment of enzymatic activity in suspensions and of confluent monolayers on microscopic coverslips ('monolayer kinetics') that APP is a cell su rface enzyme (ectoenzyme) of endothelial and lymphoid cells.