Caspase substrate

Colorimetric granzyme B substrate. Combinatorial and kinetic studies have found the IEPD sequence to be optimal for cleavage of a tetrapeptide substrate by recombinant granzyme B, with a Km for Ac-IEPD-pNA of 57 µM. Cleavage of the substrate by granzyme B releases pNA, which can be detected by its absorbance at 405 nm.