Scientific Background | 520 MMP FRET Substrate 9, 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-7, MMP-8, MMP-12 and MMP-13. MMPs participate in extracellular-matrix turnover and also process signaling proteins, receptors, cytokines and other bioactive molecules. |
Experimental Notes | The RPLALW recognition sequence is also represented in other reporter chemistries; the FAM/QXL 520 form is a separate analytical reagent with its own optical and kinetic behavior. 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. |
