Distribution of a dipeptide naphthylamidase in rat tissues and its localisation by using diazo coupling and labeled antibody techniques

Summary Several rat tissues (liver, spleen, kidney, pancreas, skin, heart, lung and brain) were shown to contain a peptidase capable of liberating naphthylamine from glycyl-dl-proline naphthylamide (Gly-Pro-NA). A single DEAE-cellulose chromatography of autodigested homogenates of the above tissues produced a partial separation of the peptidase from the enzymes hydrolysing l-leucine -naphthylamide. The Gly-Pro-NA hydrolysing enzyme was localised in tissue sections by using diazo coupling reaction and indirect immunologic techniques. Antibodies were prepared against the enzyme purified from rat liver and kidney in the rabbit. Rabbit -globulin was localized by using goat anti-rabbit -globulin labeled with fluorescein or with peroxidase.