The development of abiotic chemical reactions that can be performed in an organelle-specific manner can provide new opportunities in drug delivery and cell and chemical biology. However, due to the complexity of the cellular environment, this remains a significant challenge. Here, we introduce structurally redesigned bioorthogonal tetrazine reagents that spontaneously accumulate in mitochondria of live mammalian cells. The attributes leading to their efficient accumulation in the organelle were optimized to include the right combination of lipophilicity and positive delocalized charge. The best performing mitochondriotropic tetrazines enable subcellular chemical release of TCO-caged compounds as we show using fluorogenic substrates and mitochondrial uncoupler niclosamide. Our work demonstrates that a shrewd redesign of common bioorthogonal reagents can lead to their transformation into organelle-specific probes, opening the possibility to activate prodrugs and manipulate biological processes at the subcellular level by using purely chemical tools.

• Publikační typ
• časopisecké články MeSH

Fluorescent probes that light-up upon reaction with complementary bioorthogonal reagents are superior tools for no-wash fluorogenic bioimaging applications. In this work, a thorough study is presented on a set of seventeen structurally diverse coumarin-tetrazine probes that produce fluorescent dyes with exceptional turn-on ratios when reacted with trans-cyclooctene (TCO) and bicyclononyne (BCN) dienophiles. In general, formation of the fully aromatic pyridazine-containing dyes resulting from the reaction with BCN was found superior in terms of fluorogenicity. However, evaluation of the probes in cellular imaging experiments revealed that other factors, such as reaction kinetics and good cell permeability, prevail over the fluorescence turn-on properties. The best compound identified in this study showed excellent performance in live cell-labeling experiments and enabled no-wash fluorogenic imaging on a timescale of seconds.

• Klíčová slova
• click chemistry, coumarins, fluorescence, live cell bioimaging, tetrazines,
• MeSH
• fluorescenční barviva analýza   MeSH
• heterocyklické sloučeniny analýza   MeSH
• konfokální mikroskopie MeSH
• kumariny analýza   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• optické zobrazování * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fluorescenční barviva MeSH
• heterocyklické sloučeniny MeSH
• kumariny MeSH

Fluorogenic bioorthogonal reactions enable visualization of biomolecules with excellent signal-to-noise ratio. A bicyclononyne-tetrazine ligation that produces fluorescent pyridazine products has been developed. In stark contrast to previous approaches, the formation of the dye is an inherent result of the chemical reaction and no additional fluorophores are needed in the reagents. The crucial structural elements that determine dye formation are electron-donating groups present in the starting tetrazine unit. The newly formed pyridazine fluorophores show interesting photophysical properties the fluorescence intensity increase in the reaction can reach an excellent 900-fold. Model imaging experiments demonstrate the application potential of this new fluorogenic bioorthogonal reaction.

• Klíčová slova
• Diels-Alder reactions, cyclic alkynes, cycloaddition reactions, fluorogenic probes, tetrazines,
• MeSH
• cykloadiční reakce MeSH
• fluorescenční barviva chemie   MeSH
• heterocyklické sloučeniny monocyklické chemie   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• můstkové bicyklické sloučeniny chemie   MeSH
• nádorové buněčné linie MeSH
• pyridaziny chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fluorescenční barviva MeSH
• heterocyklické sloučeniny monocyklické MeSH
• můstkové bicyklické sloučeniny MeSH
• pyridaziny MeSH