title: An azide-modified nucleoside for metabolic labeling of DNA.
abstract: Metabolic incorporation of azido nucleoside analogues into living cells can enable sensitive detection of DNA replication through copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and strain-promoted azide-alkyne cycloaddition (SPAAC) "click" reactions. One major limitation to this approach is the poor chemical stability of nucleoside derivatives containing an aryl azide group. For example, 5-azido-2'-deoxyuridine (AdU) exhibits a 4 h half-life in water, and it gives little or no detectable labeling of cellular DNA. In contrast, the benzylic azide 5-(azidomethyl)-2'-deoxyuridine (AmdU) is stable in solution at 37 °C, and it gives robust labeling of cellular DNA upon addition of fluorescent alkyne derivatives. In addition to providing the first examples of metabolic incorporation into and imaging of azide groups in cellular DNA, these results highlight the general importance of assessing azide group stability in bioorthogonal chemical reporter strategies.
authors.affiliation: Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland) http://www.bioorganic-chemistry.com.
authors.forename: Anne B
authors.initials: AB
authors.lastname: Neef
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Luedtke
mesh_terms: D000480:Alkynes / Q000737:chemistry; D001386:Azides / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D061565:Cycloaddition Reaction; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004261:DNA Replication; D003856:Deoxyuracil Nucleotides / Q000378:metabolism; D003857:Deoxyuridine / Q000737:chemistry* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans
chemical_list: D000480:Alkynes; D001386:Azides; D003856:Deoxyuracil Nucleotides; D005456:Fluorescent Dyes; C048865:5-azido-2'-deoxyuridine 5'-triphosphate; D003300:Copper; D004247:DNA; D003857:Deoxyuridine
keywords: DNA replication; azides; bioorthogonal functional groups; click chemistry; fluorescent probes; metabolic labeling