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 3.4.24.23) cleaves the substrate at the Gly-Leu bond with a 190-fold increase in fluorescence (Abs/Em = 325/393 nm).