title: Labeling live cells by copper-catalyzed alkyne--azide click chemistry.
abstract: The copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, optimized for biological molecules in aqueous buffers, has been shown to rapidly label mammalian cells in culture with no loss in cell viability. Metabolic uptake and display of the azide derivative of N-acetylmannosamine developed by Bertozzi, followed by CuAAC ligation using sodium ascorbate and the ligand tris(hydroxypropyltriazolyl)methylamine (THPTA), gave rise to abundant covalent attachment of dye-alkyne reactants. THPTA serves both to accelerate the CuAAC reaction and to protect the cells from damage by oxidative agents produced by the Cu-catalyzed reduction of oxygen by ascorbate, which is required to maintain the metal in the active +1 oxidation state. This procedure extends the application of this fastest of azide-based bioorthogonal reactions to the exterior of living cells.
authors.affiliation: Department of Cell Biology, The Scripps Research Institute, La Jolla, California, USA.
authors.forename: Vu
authors.initials: V
authors.lastname: Hong
authors.forename: Nicole F
authors.initials: NF
authors.lastname: Steinmetz
authors.forename: Marianne
authors.initials: M
authors.lastname: Manchester
authors.forename: M G
authors.initials: MG
authors.lastname: Finn
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D000818:Animals; D001205:Ascorbic Acid / Q000737:chemistry / Q000494:pharmacology; D001386:Azides / Q000737:chemistry*; D016466:CHO Cells; D002384:Catalysis; D002470:Cell Survival / Q000187:drug effects; D057930:Click Chemistry; D003300:Copper / Q000737:chemistry*; D006224:Cricetinae; D003412:Cricetulus; D006367:HeLa Cells; D006801:Humans; D019169:Jurkat Cells; D011134:Polysaccharides / Q000737:chemistry; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D000480:Alkynes; D001386:Azides; D011134:Polysaccharides; D003300:Copper; D001205:Ascorbic Acid