[Peptidases. I. Histochemical investigations with 2-naphthylamides and hexazonium-p-rosanilin (author's transl)]

Using fresh frozen (with and without semipermeable membranes), freeze-dried or sections from aldehyde fixed material and hexazotized p-rosaniline for simultaneous coupling more than 20 different unsubstituted or substituted L-amino acid naphthylamides are split especially in the microvilli and/or stereocilia of the small intestine, kidney and epididymis from rats. Further sites of positive reactions can be revealed by L-alanyl, L-leucyl, L-lysyl, alpha,L-glutamyl, gamma,L-glutamyl, L-asparaginyl, N-benzoyl-L-arginyl, N-carbobenzoxy-L-arginyl and N-benzoyl-L-phenylalanyl 2-naphthylamide. Among the substituted and unsubstituted peptide 2-naphthylamides L-prolyl-L-arginyl 2-naphthylamide is not hydrolysed in visible amounts; L-arginyl-L-arginyl, L-alanyl-L-arginyl-L-arginyl, L-alanyl-L-leucyl-L-tyrosyl, L-histidyl-L-seryl, L-seryl-L-tyrosyl and L-glycy-L-phenylalanyl 2-naphthylamide are metabolized in the renal and intestinal brush border; the reaction pattern obtained with N-carbobenzoxy-L-glycyl-L-glycyl-L-arginyl 2-naphthylamide differs from that of N-carbobenzoxy-L-arginyl 2-naphthylamide. In addition L-glycyl-L-prolyl, L-leucyl-L-alanyl, L-lysyl-L-alanyl and L-alanyl-L-phenylalanyl-L-prolyl 2-naphthylamide are also split in the lysosomes of many organs and the secretion granules of gland cells.