title: A fluorescent assay of proteinases in cultured mammalian cells.
abstract: We have demonstrated proteinase activity in unfixed cells grown on tissue culture plates with a technique using 5-nitrosalicylaldehyde and peptide derivatives of 4-methoxy-2-naphthylamine. The 4-methoxy-2-naphthylamine liberated by proteinase activity reacts with 5-nitrosalicylaldehyde to form a fluorescent product. The substrates CBZ-alanyl-arginyl-arginyl-4-methoxy-2-naphthylamine and lysyl-alanyl-4-methoxy-2-naphthylamine, were used for the direct visual detection of two arylamidase activities in BALB/c 3T3 and C3H 10T 1/2 cells. With low magnification these enzyme activities can be detected in single clones; with higher magnification the fluorescent product can be seen within the cytoplasm of single cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008856:Microscopy, Fluorescence; D010447:Peptide Hydrolases / Q000032:analysis*; D010455:Peptides; D013379:Substrate Specificity
chemical_list: D010455:Peptides; D010447:Peptide Hydrolases