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Peptide‐Based Probes with an Artificial Anion‐Binding Motif for Direct Fluorescence “Switch‐On” Detection of Nucleic Acid in Cells
Author(s) -
Maity Debabrata,
Matković Marija,
Li Shang,
Ehlers Martin,
Wu Junchen,
Piantanida Ivo,
Schmuck Carsten
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201703813
Subject(s) - polynucleotide , circular dichroism , fluorescence , dna , fluorophore , chemistry , nucleic acid , peptide , intercalation (chemistry) , rna , peptide nucleic acid , fluorescence anisotropy , biochemistry , biophysics , biology , membrane , gene , physics , inorganic chemistry , quantum mechanics
This work reports two new peptide‐based fluorescence probes ( 1 and 2 ) for the detection of ds‐DNA at physiological pH. Probes 1 and 2 contain a fluorophore, either amino‐naphthalimide or diethyl‐aminocoumarin, respectively, and two identical peptide arms each equipped with a guanidiniocarbonylpyrrole (GCP) anion‐binding motif. These probes show “switch‐on” fluorescence response upon binding to ds‐DNA, whereby they can differentiate between various types of polynucleotides. For instance, they exhibit more pronounced fluorescence response for AT‐rich polynucleotides than GC‐rich polynucleotides, and both give only negligible response to ds‐RNA. The fluorimetric response of 1 is proportional to the AT‐basepair content in DNA, whereas the fluorescence of 2 is sensitive to the secondary structure of the polynucleotide. Fluorescence experiments, thermal melting experiments and circular dichroism studies suggest that 1 interacts with ds‐DNA in a combined intercalation and minor groove binding, whereas 2 interacts mainly with the outer surface of DNA/RNA. As 1 and 2 have a very low cytotoxicity, 1 can be applied for the imaging of nuclear DNA in cells.