520 MMP FRET Substrate 3, FAM/QXL520

520 MMP FRET Substrate 3, FAM/QXL520 is an internally quenched peptide designed for fluorescence-resonance-energy-transfer measurements of matrix metalloproteinase activity. The peptide combines an MMP-sensitive recognition sequence with the 5-FAM/QXL 520 reporter pair. In the intact molecule, QXL 520 suppresses 5-FAM fluorescence; proteolytic cleavage separates the reporter pair and restores green fluorescence near 494/521 nm. The verified LifeTein activity profile includes MMP-1, MMP-2, MMP-8, MMP-9, MMP-12, MMP-13 and MMP-14. MMPs participate in extracellular-matrix turnover and also process signaling proteins, receptors, cytokines and other bioactive molecules.

• matrix metalloproteinase activity assays
• extracellular-matrix remodeling research
• MMP inhibitor screening
• fluorescent protease assay development

The sequence contains methyl-cysteine and D-arginine, making it chemically distinct from simpler PLGL-based MMP substrates. MMP peptide substrates generally show overlapping enzyme specificity, so activity in complex samples should be assigned with purified enzymes, selective inhibitors, or orthogonal controls. Protect the FAM/QXL 520 reagent from light.

1. Matrix Metalloproteinases: Structure, Function, and Their Exploitation as Therapeutic Targets in Cancer
2. Matrix Metalloproteinases in Health and Disease