Matrix Metalloproteinases (MMPs) are a large family of endopeptidases. Collectively, MMPs can degrade all kinds of extracellular matrix proteins, and can also process a number of bioactive molecules. They are known to be involved in the cleavage of cell surface receptors, the release of apoptotic ligands, and chemokine/cytokine inactivation. MMPs are also thought to play a major role in cell behaviors such as cell proliferation, migration (adhesion/dispersion), differentiation, angiogenesis, apoptosis, and host defense. This peptide is a fluorogenic substrate that is best cleaved by MMP-7, 8, 9 and 13. The highly fluorescent Mca moiety is efficiently quenched by energy transfer to the Dnp group. The punctuated metallo proteinase (PUMP, EC 184.108.40.206) cleaves the substrate at the Gly-Leu bond with a 190-fold increase in fluorescence (Abs/Em = 325/393 nm). In human MMP assays, this substrate is about 50 to 100 times more sensitive than the generic MMP substrate, Dnp-PLGLWAr-NH2.