9-Azide-9-deoxy-sialic acid: a precision chemical probe for glycobiological research 160555-88-4

9-Azide-9-deoxy-sialic acid, whose chemical name is N-acetyl-9-azido-9-deoxy-α-Neuraminic acid, is a carefully engineered derivative of the sialic acid family. As a key metabolic probe reagent, it provides researchers with a powerful and specific tool for visualizing, capturing, and analyzing dynamic glycosylation processes through efficient incorporation into the sialic acid sugar chain metabolic pathway to deeply explore the complex biological functions of the cell surface glycocalyx.

Chemical Information

Chemical name: N-acetyl-9-azido-9-deoxy-α-Neuraminic acid

Common name: 9-azido-9-deoxy-sialic acid

Chemical formula: C11H18N4O8

Molecular weight: 334.29 g/mol

CAS number: 160555-88-4

Category: Metabolic Probe Reagents

Structural characteristics and chemical properties

This molecule is precisely modified based on the structure of natural sialic acid (N-acetylneuraminic acid):

• Site-specific modification: On the 9th carbon atom of the sialic acid ring, the hydroxyl group is replaced by an azide group. This modification achieves minimal structural interference, ensuring that it can be recognized and utilized by the intracellular sialic acid metabolic pathway, while introducing a unique chemical biology handle.

• Highly reactive azide group: The introduced azide group remains inert under physiological conditions but allows efficient and specific cycloaddition reactions with alkyne labels via copper-catalyzed click chemistry. In addition, it can also be connected under copper-free conditions via strain-promoted click chemistry, making it suitable for live cell research.

• Metabolic compatibility: The modified molecule retains the ability to enter cells through cell membrane transporters and be activated by sialic acid synthetase into CMP-sialic acid derivatives, which are ultimately recognized by cell surface or secreted sialyltransferases and incorporated into the termini of newly synthesized glycoproteins and glycolipids.

Main applications and advantages

Dynamic labeling and imaging of cell surface glycocalyx

As a core tool for metabolic glycoengineering, 9-azido-9-deoxy-sialic acid can be taken up by cells and metabolically incorporated into cell surface glycan termini. Subsequently, click chemistry was used to covalently link it to a fluorescent dye containing an alkynyl group to achieve highly specific and high spatial and temporal resolution fluorescence imaging of sialylation modifications on the surface of living or fixed cells. This technology avoids possible cross-reactions with traditional antibody markers and provides an intuitive means for studying dynamic changes in the glycocalyx during cell differentiation, immune recognition, pathogen infection, etc.

Enrichment and identification of sialylated glycoconjugates

Combined with click chemistry-based bioorthogonal ligation, this probe can be used to isolate and enrich newly synthesized sialylated proteins or glycolipids. For example, by performing a click reaction between azide-labeled glycoconjugates and solid-supported alkynes, molecules containing the probe can be specifically captured from complex cell lysates or body fluid samples, followed by mass spectrometry analysis to systematically draw sialylation modification maps and discover disease-related glycosylation markers.

Virus-host interaction studies

Many viruses use sialic acid on the surface of host cells as receptors for adsorption and invasion. By introducing 9-azido-9-deoxy-sialic acid into the glycocalyx of host cells through metabolic labeling technology, not only can the binding sites of viral particles be visualized, but blockers or cross-linking agents can also be introduced through click chemistry to study or intervene in the virus attachment process, providing new strategies for the development of antiviral drugs.

Research on tumor immunity and immune checkpoint regulation

Abnormal sialylation modifications (such as overexpression) on the surface of tumor cells are closely related to immune evasion. This probe can be used to accurately label tumor-associated sialic acid antigens and study their interactions with immune checkpoint receptors such as the Siglec family, which will help elucidate the immune suppression mechanism and develop corresponding glycoimmunotherapy.

Conclusion

9-Azide-9-deoxy-sialic acid transcends its role as a simple chemical and serves as a bridge between chemical synthesis and complex glycobiological functions in living systems. Its high efficiency and specificity in metabolic glycoengineering make it possible to analyze the spatiotemporal dynamics of sialylation, a key post-translational modification, at the in vivo level without interference. From basic cell biology to the study of disease mechanisms to the discovery of novel therapeutic targets, this sophisticated tool continues to advance the frontiers of glycoscience and provides indispensable insights for researchers in the life sciences.

The above information is provided by the editor of KASONS and is for scientific research only.