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

• Published in: Bioconjugate chemistry Vol. 29; no. 4; pp. 1312 - 1318
• Main Authors: Knorr, Gergely, Kozma, Eszter, Schaart, Judith M, Németh, Krisztina, Török, György, Kele, Péter
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 18.04.2018; Amer Chemical Soc
• Subjects: Actin; Actin Cytoskeleton - ultrastructure; Animals; Biochemical Research Methods; Biochemistry & Molecular Biology; Carbocyanines - chemistry; Cercopithecus aethiops; Chemical elements; Chemical reactions; Chemistry; Chemistry, Multidisciplinary; Chemistry, Organic; COS Cells; Cytoskeleton; Fluorescence; Fluorescent Dyes - chemistry; Heterocyclic Compounds, 1-Ring - chemistry; Image resolution; Infrared imaging systems; Labeling; Life Sciences & Biomedicine; Microscopy; Microscopy, Confocal - methods; Optical Imaging - methods; Physical Sciences; Probes; Proteins; Quenching; Science & Technology; Spectrometry, Fluorescence - methods; FLUOROPHORES; DIELS-ALDER REACTIONS; AMINO-ACIDS; PERFORMANCE; MICROSCOPY; TAGS; LIVING CELLS; PROBES
• ISSN: 1043-1802; 1520-4812
• DOI: 10.1021/acs.bioconjchem.8b00061

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.