Azide-based bioorthogonal chemistry: Reactions and its advances in cellular and biomolecular imaging

Abstract

Since the term “bioorthogonal” was first demonstrated in 2003, new tools for bioorthogonal chemistry have been rapidly developed. Bioorthogonal chemistry has now been widely utilized for applications in imaging various biomolecules, such as proteins, glycoconjugates, nucleic acids, and lipids. Contrasting the chemical reactions or synthesis that are typically executed in vitro with organic solvents, bioorthogonal reactions can occur inside cells under physiological conditions. Functional groups or chemical reporters for bioorthogonal chemistry are highly selective and will not perturb the native functions of biological systems. Advances in azide-based bioorthogonal chemical reporters make it possible to perform chemical reactions in living systems for wide-ranging applications. This review discusses the milestones of azide-based bioorthogonal reactions, from Staudinger ligation and copper(I)-catalyzed azide-alkyne cycloaddition to strain-promoted azide-alkyne cycloaddition. The development of bioorthogonal reporters and their capability of being built into biomolecules in vivo have been extensively applied in cellular imaging. We focus on strategies used for metabolic incorporation of chemically tagged molecular building blocks (e.g., amino acids, carbohydrates, nucleotides, and lipids) into cells via cellular machinery systems. With the aid of exogenous bioorthogonally compatible small fluorescent probes, we can selectively visualize intracellular architectures, such as protein, glycans, nucleic acids, and lipids, with high specificity to help in answering complex biological problems.

Lanthanide Complex for Single-Molecule Fluorescent in Situ Hybridization and Background-Free Imaging

“…Specifically, we coupled BHHBCB•Eu 3+ to an aminodibenzocyclooctyne (DBCO) linker, enabling the indirect luminescent FISH method via specific bioorthogonal chemistry. 37 Under the excitation of 342 nm, the emission spectrum of Eu 3+ prominently features a peak at 621 nm, stemming from the 5 D 0 → 7 F 2 transition. The minor emission peak at around 580 nm is associated with the 5 D 0 → 7 F 0 transition.…”

“…The probes were prepared by incorporating azide-dUTP at a 100% rate, followed by coupling high-density lanthanide complexes. Specifically, we coupled BHHBCB·Eu 3+ to an amino-dibenzocyclooctyne (DBCO) linker, enabling the indirect luminescent FISH method via specific bioorthogonal chemistry . Under the excitation of 342 nm, the emission spectrum of Eu 3+ prominently features a peak at 621 nm, stemming from the 5 D 0 → 7 F 2 transition.…”

The Synthesis of Molecular Probes Based on Cystic Fibrosis Drugs for Biological Research

“…173 However, the reaction requires high temperatures to overcome the activation barrier of deforming the alkyne bond angle to promote cycloaddition and triazole formation (a mixture of isomeric products is often observed, Figure 5.3a), which are not compatible with biological systems. 172,173 A modification of the Huisgen reaction was reported by two independent groups (Sharpless et al and Meldal et al) demonstrating that the use of copper (I) as a catalyst significantly increases the rate of the cycloaddition at physiological temperature and over a broad pH range (Figure 5.3b). [174][175][176][177][178][179] However, the use of copper is known to form reactive oxygen species that may be toxic to the living system.…”

“…Bioorthogonal reaction can be either a strain-promoted alkyne-azide cycloaddition (SPAAC) or inverse electron-demand Diels-Alder cycloaddition (IEDDA). [170][171][172] In this work, BCNK is incorporated via genetic code expansion into mini-Turbo BirA and will undergo a reaction with either an azide or tetrazine derivative which is explained in subsequent sections.…”

3-Aryl-2-azidopropanoic acids in cycloaddition reactions

“…Такі речовини мають перспективи застосування у медичній та фармацевтичній хімії. Крім того, біоортогональні хімічні репортери на основі азидів дають можливість проводити хімічні реакції у живих системах для широкого застосування [5]. Зважаючи на це, дослідження реакційної здатності нових органічних азидів залишається актуальним завданням.…”