Title
Versatile cyanine-click-amino acid conjugates showing one-atom-influenced recognition of DNA/RNA secondary structure and mitochondrial localization in living cells
Author
Tamara Smidlehner, Atanas Kurutos, Jakov Slade, Robert Belužić, Dale L. Ang, Alison Rodger, Ivo Piantanida
Year
2018
Journal
European Journal of Organic Chemistry
Abstract
By a simple click-CuAAC procedure several cyanine dye analogues were attached to the amino acid side chain, yielding chromophore-amino acid conjugates, with potential of fluorescence upon binding to target. Due to the amino acid C- and N-termini available for peptide coupling, these conjugates are suitable for easy incorporation into a peptide backbone. Moreover, "click" procedures also allow post-peptide synthesis attachment of the dye. Novel amino acid dyes, although intrinsically non-fluorescent, give rise to strong fluorimetric response upon binding to double-stranded (ds)-DNAs or ds-RNA, whereby selectivity in emission response to various polynucleotide secondary structures is controlled either by linker length or halogen atom located on the cyanine part of the molecule. Molecular modeling confirmed the mode of binding to different polynucleotides, which was responsible for recognition. Interestingly, cell localisation experiments show that the dyes were specifically localised in mitochondria at variance with the localisation of parent dyes, which accumulate in cell nuclei, pointing out that the amino acid tail (containing triazole ring) might function as a novel mitochondria-directing appendage
Instrument
J-815
Keywords
Circular dichroism, Induced circular dichroism, Linear dichroism, DNA structure, Ligand binding, Organic chemistry, Biochemistry