title: Polarity Sensitive Bioorthogonally Applicable Far-Red Emitting Labels for Postsynthetic Nucleic Acid Labeling by Copper-Catalyzed and Copper-Free Cycloaddition.
abstract: Two series of new, water-soluble, membrane-permeable, far-red/NIR emitting benzothiazolium-based fluorescent labels with large Stokes' shifts were synthesized that can be conjugated to alkyne-modified biomolecules through their azide moiety via azide-alkyne cycloaddition. We have used these azide bearing labels to make fluorescent DNA constructs using copper-catalyzed "click" reaction. All dyes showed good or remarkable fluorescence intensity enhancement upon conjugation to DNA. We also investigated the possibility to incorporate the benzocyclooctyne motif through rigid (ethnynyl) or flexible (ethyl) linkers into the DNA, thus enabling copper-free labeling schemes. We observed that there is a marked difference between the two linkers applied in terms of optical properties of the labeled oligonucleotides. We have also tested the in vivo labeling potential of these newly synthesized dyes on HeLa cells previously transfected with cyclooctynylated DNA. Confocal fluorescent images showed that the dyes are all able to cross the membrane and suitable for background-fluorescence free fluorescent tagging of nucleic acids. Moreover, we have observed different accumulation of the two dye series in the endosomal particles, or in the nuclei, respectively.
authors.affiliation: Chemical Biology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences . Magyar tudósok krt. 2, H-1117, Budapest, Hungary.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Eördögh
authors.affiliation: Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
authors.forename: Jeannine
authors.initials: J
authors.lastname: Steinmeyer
authors.affiliation: Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
authors.forename: Krisana
authors.initials: K
authors.lastname: Peewasan
authors.affiliation: Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT) , H.-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Schepers
authors.affiliation: Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
authors.forename: Hans-Achim
authors.initials: HA
authors.lastname: Wagenknecht
authors.affiliation: Chemical Biology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences . Magyar tudósok krt. 2, H-1117, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Kele
mesh_terms: D000480:Alkynes / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D052160:Benzothiazoles / Q000737:chemistry; D002384:Catalysis; D057930:Click Chemistry; D003300:Copper / Q000737:chemistry*; D061565:Cycloaddition Reaction; D004247:DNA / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D061848:Optical Imaging
chemical_list: D000480:Alkynes; D001386:Azides; D052160:Benzothiazoles; D005456:Fluorescent Dyes; D003300:Copper; D004247:DNA