title: Synthesis and spectroscopic properties of 4-ethoxymethylene-2-(1)-naphthyl-5(4H)-oxazolone-labeled fluorescent peptides.
abstract: Strategies for the preparation of new fluorescent oligopeptide conjugates labeled with 4-ethoxymethylene-2-[1]-naphthyl-5(4H)-oxazolone (naOx-OEt) at the N-terminal on solid support or in solution have been devised. These procedures are simple and easy to carry out by reacting naOx-OEt or N(alpha)-naOx-amino acid with side chain protected peptide chains attached to resins. The integrity of the N-alkyl bond was maintained even after the trifluoracetic acid or HF based cleavages procedures. Our data show that the naOx fluorophore is compatible with both Fmoc/tBu and Boc/Bzl methods and also suggest that naOx-amino acid could be utilized as building blocks for solid phase peptide synthesis. Comparative analysis of fluorescence properties of naOx-conjugates indicated that the spectral properties of the fluorophore do not change after incorporating into peptides. The compact size, the definite chemical reaction for its introduction in combination with the appropriate spectral features (e.g., intense emission, pH independent fluorescent characteristics, and beneficial photobleaching dose constant and rates) and with chemical and spectral stability, naOx-based labeling could be attractive for novel cellular fluorescent techniques (e.g., in laser scanning confocal FRET) to study peptide-protein and protein-protein interactions even in biological matrices.
authors.affiliation: Research Group of Peptide Chemistry, Eötvös Loránd University, Budapest 112,POB 32, Hungary, H-1518.
authors.forename: Szilvia
authors.initials: S
authors.lastname: Bosze
authors.forename: Gabriella
authors.initials: G
authors.lastname: Csík
authors.forename: György
authors.initials: G
authors.lastname: Kóczán
authors.forename: Ferenc
authors.initials: F
authors.lastname: Hudecz
mesh_terms: D000478:Alkylation; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D009284:Naphthols / Q000737:chemistry*; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D010080:Oxazoles / Q000138:chemical synthesis* / Q000737:chemistry; D010081:Oxazolone / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C510761:4-ethoxymethylene-2-(1)-naphthyl-5(4H)-oxazolone; D005456:Fluorescent Dyes; D009281:Naphthalenes; D009284:Naphthols; D009842:Oligopeptides; D010080:Oxazoles; D010081:Oxazolone