In our previous paper we showed that the MMP-9 enzyme recognizes a specific peptide sequence, Lys-Gly-
Pro-Arg-Ser-Leu-Ser-Gly-Lys, and cleaves the peptide into two parts . In this study, the peptide is labeled with two
dyes, carboxyfluorescein (5-FAM) and Cy5. A highly efficient energy transfer of over 80% results in a dominant
emission of Cy5 at ~670 nm with an excitation of 470 nm. Severance of the peptide by the MMP-9 enzyme
eliminates Förster Resonance Energy Transfer (FRET) and strongly increases the fluorescence of the 5-FAM dye.
In this manuscript we describe the strategy for a FRET-based method for MMP-9 enzyme detection. The basic aim is to apply
a ratio-metric sensing technique in which a ratio of green/red fluorescence intensity is measured as a function of enzyme
concentration. The ratio-metric method eliminates many experimental variables and enables accurate MMP-9 detection.
Keywords: Fluorescence, FRET, labeled peptide, MMP-9, ratio-metric sensing.
Rights & PermissionsPrintExport