title: Fluorescent Peptide Beacons for the Selective Ratiometric Detection of Heparin.
abstract: Heparin is extensively used as an anticoagulant drug during surgery. Two fluorophore-functionalized cationic oligopeptides HS 1 and HS 2 were developed to monitor heparin ratiometrically in aqueous media. Upon binding to heparin, HS 1 and HS 2 undergo a conformational change from an open form to a folded form, which leads to a distinct change in the fluorescence properties. HS 1 switches from pyrene monomer emission to an excimer emission. For HS 2, a fluorescence resonance energy transfer (FRET) process is enabled between a naphthalene donor and a dansyl acceptor. This method is highly selective for heparin relative to other similar biological analytes such as hyaluronic acid or chondroitin sulfate. HS 1 and HS 2 could also detect heparin ratiometrically in diluted bovine serum. The strong ratiometric emission color change can also be observed by the naked eye. Addition of the polycationic protein protamine releases both HS 1 and HS 2 from their heparin complex, which simultaneously restores pyrene monomer emission for the first case and decreases the FRET process for the latter case, respectively. Dynamic light scattering (DLS) and AFM studies confirm aggregate formation of heparin with HS 1 and HS 2.
authors.affiliation: Institute for Organic Chemistry, University of Duisburg-Essen, 45117, Essen, Germany.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Maity
authors.affiliation: Institute for Organic Chemistry, University of Duisburg-Essen, 45117, Essen, Germany. carsten.schmuck@uni-due.de.
authors.forename: Carsten
authors.initials: C
authors.lastname: Schmuck
mesh_terms: D000818:Animals; D002417:Cattle; D002809:Chondroitin Sulfates / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D006493:Heparin / Q000097:blood / Q000737:chemistry*; D006820:Hyaluronic Acid / Q000737:chemistry; D057230:Limit of Detection; D009281:Naphthalenes / Q000737:chemistry; D009842:Oligopeptides / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry; D000071228:Polyelectrolytes; D011485:Protein Binding; D011487:Protein Conformation; D011721:Pyrenes / Q000737:chemistry
chemical_list: D002809:Chondroitin Sulfates; D005456:Fluorescent Dyes; D006493:Heparin; D006820:Hyaluronic Acid; D009281:Naphthalenes; D009842:Oligopeptides; D011073:Polyamines; D000071228:Polyelectrolytes; D011721:Pyrenes; C030984:pyrene
keywords: fluorescence resonance energy transfer; heparin; peptide beacon; ratiometric sensing; supramolecular chemistry