title: Protease probes that enable excimer signaling upon scission.
abstract: Peptide-based probes that fluoresce upon proteolytic cleavage are invaluable tools for monitoring protease activity. The read-out of protease activity through pyrene excimer signaling would be a valuable asset because the large Stokes shift and the long lifetime of the excimer emission facilitate measurements in autofluorescent media such as blood serum. However, proteolytic cleavage abolishes rather than installs the proximity relationships required for excimer signaling. Herein, we introduce a new probe architecture to enable the switching on of pyrene excimer emission upon proteolytic scission. The method relies on hairpin-structured peptide nucleic acid (PNA)/peptide hybrids with pyrene units and anthraquinone-based quencher residues positioned in a zipper-like arrangement within the PNA stem. The excimer hairpin peptide beacons afforded up to a 50-fold enhancement of the pyrene excimer emission. Time-resolved measurements allowed the detection of matrix metalloprotease 7 in human blood serum.
authors.affiliation: Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin (Germany).
authors.forename: Melanie
authors.initials: M
authors.lastname: Fischbach
authors.forename: Ute
authors.initials: U
authors.lastname: Resch-Genger
authors.forename: Oliver
authors.initials: O
authors.lastname: Seitz
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D010447:Peptide Hydrolases / Q000737:chemistry*; D015398:Signal Transduction
chemical_list: D005456:Fluorescent Dyes; D010447:Peptide Hydrolases
keywords: excimers; fluorescent probes; peptide nucleic acids; proteases; time-resolved fluorescence