Enzyme Substrates

XTT (2,3-Bis-(2-Methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide, disodium salt) is a tetrazolium derivative used widely in cell viability and proliferation testing. The material is readily reduced in viable cells to a highly water-soluble orange colored product (λ= 475 nm).

Z-AA-R110-PEG (Rhodamine 110-PEG, N-CBZ-L-alanyl-L-alanine amide) is a substrate for elastate.

Z-AAD-R110 is a substrate for granzyme B. Granzyme B from T lymphocytes and natural killer cells induces apoptosis in target cells by activating caspases and causing mitochondrial cytochrome C release.

Z-FR-AMC is a substrate for serine proteases, including cathepsins, kallikrein and plasmin.

Z-FR-R110 (Rhodamine 110, bis-(N-CBZ-L-phenylalanyl-L-arginine amide), dihydrochloride) is a substrate for the cysteine proteases cathepsins B and L. The substrate has been used in flow cytometry studies of human monocytes and rat macrophages.