Bioorthogonal Reactions in Bioimaging

Abstract

Visualization of biomolecules in their native environment or imaging-aided understanding of more complex biomolecular processes are one of the focus areas of chemical biology research, which requires selective, often site-specific labeling of targets. This challenging task is effectively addressed by bioorthogonal chemistry tools in combination with advanced synthetic biology methods. Today, the smart combination of the elements of the bioorthogonal toolbox allows selective installation of multiple markers to selected targets, enabling multicolor or multimodal imaging of biomolecules. Furthermore, recent developments in bioorthogonally applicable probe design that meet the growing demands of superresolution microscopy enable more complex questions to be addressed. These novel, advanced probes enable highly sensitive, low-background, single- or multiphoton imaging of biological species and events in live organisms at resolutions comparable to the size of the biomolecule of interest. Herein, the latest developments in bioorthogonal fluorescent probe design and labeling schemes will be discussed in the context of in cellulo/in vivo (multicolor and/or superresolved) imaging schemes. The second part focuses on the importance of genetically engineered minimal bioorthogonal tags, with a particular interest in site-specific protein tagging applications to answer biological questions.

Recognizing the Beauty of Myelination through Identifying Sites of Phospholipid, Protein, and RNA Syntheses and Characterizing Their Movements in Myelin Internodes

“…Where Proteins of Interest Are Synthesized and to Follow Movements from These Sites to Sites of Residence In addition to using bio-orthogonal precursors for amino acids that incorporate into all proteins, current approaches have gone a step further in using genetic code expansion to target bio-orthogonal amino acids to specific sites of proteins of interest [110,[129][130][131][132][133]. Because this approach is mostly carried out under in vitro conditions, it would seem reasonable to study trafficking of proteins of interest in the in vitro conditions examine in the previous (3.…”

Photoinduced Charge Centralization Quenches the Fluorescence of Conjugation-Fused Tetrazine Labels with Red-to-Near-Infrared Emissions

“…Tetrazine-based fluorogenic labels attract significant attention across various research communities in life sciences, − due to their exceptional combinations of several favorable properties: outstanding chemoselectivity, excellent biocompatibility, tunable optical properties, and distinctive fluorescence enhancement (FE) effects. − Typically, these labels exhibit minimal fluorescence in the presence of tetrazine moiety. However, a significant increment in fluorescence is observed upon tetrazine disintegrations via click reactions. − This unique fluorogenic effect significantly improves signal-to-noise ratios, leading to widespread utilization in bioimaging, − drug delivery, − as well as pathophysiological diagnostics and therapy. − However, a key challenge lies in the fact that most labels with high FE ratios primarily emit in the visible region, with a diminishing FE as the emission wavelengths shift into the deep-red and near-infrared (NIR) regions. − Therefore, developing new strategies to enhance FE ratios, particularly for NIR-emitting labels, is crucial for optimizing their fluorogenicity.…”