Bioorthogonally Applicable Fluorogenic Cyanine-Tetrazines for No-Wash Super-Resolution Imaging

Bioconjug Chem. 2018 Apr 18;29(4):1312-1318. doi: 10.1021/acs.bioconjchem.8b00061. Epub 2018 Feb 20.

Abstract

The synthesis, fluorogenic characterization, and labeling application of four tetrazine-quenched cyanine probes with emission maxima in the red-far red range is reported. Fluorescence of the cyanine-cores is quenched via through-bond-energy-transfer (TBET) exerted by a bioorthogonal tetrazine unit. Upon bioorthogonal labeling reaction with cyclooctyne tagged proteins, the quenching effect ceases, and thus the fluorescence reinstates, resulting in an increase in fluorescence intensity. As a rare example among indocyanines, one of our new probes was found suitable in STED-based super-resolution imaging. The applicability of this fluorogenic Tet-Cy3 probe was therefore further demonstrated in the bioorthogonal labeling of cytoskeletal protein, actin, with subsequent super-resolution microscopy (STED) imaging even under no-wash conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / ultrastructure
  • Animals
  • COS Cells
  • Carbocyanines / chemistry*
  • Chlorocebus aethiops
  • Fluorescent Dyes / chemistry*
  • Heterocyclic Compounds, 1-Ring / chemistry*
  • Microscopy, Confocal / methods
  • Optical Imaging / methods*
  • Spectrometry, Fluorescence / methods

Substances

  • Carbocyanines
  • Fluorescent Dyes
  • Heterocyclic Compounds, 1-Ring