Arylamidases of rat liver and kidney.

The subcellular distribution of arylamidases in rat liver and rat kidney was studied. Lysosomes prepared from both tissues had the highest concentration of arylamidases. Different types of arylamidases have been found in the lysosomes and microsomes of these tissues. The lysosomal enzymes were inhibited by divalent metal ions, lost activity on storage, were inhibited by p-chloromercuribenzoate, and were activated by dithiothreitol. The lysosomal enzymes from both tissues were most active against L-arginyl-/3naphthylamide. The microsomal enzymes from both liver and kidney were activated by divalent metal ions and were stable on storage. The kidney microsomal enzyme was not inhibited by p-chloromercuribenzoate. The Co++-activated microsomal enzyme was most active against L-alanyl-finaphthylamide.