Ac4ManNAl—Precision probe for glycobiology research 935658-93-8

N-(4'-pentynoyl)-1,2,3,6-O-tetraacetyl-D-mannosamine is a carefully designed metabolic sugar probe and an indispensable tool molecule in modern chemical glycobiology research. It cleverly combines bioorthogonal chemistry with cellular metabolic engineering, providing researchers with a powerful means to specifically label, track and study the sialylation process in a living system.

Chemical Information

Chemical name: N-(4'-pentynoyl)-1,2,3,6-O-tetraacetyl-D-mannosamine

Common name: Ac4ManNAl

Chemical formula: C19H25NO10

Molecular weight: 427.4 g/mol

CAS number: 935658-93-8

Category: Metabolic Probe Reagents

Structural features

The structure of this molecule has been dually functionalized to possess both metabolic activity and reaction specificity:

• Acetylation protecting group: The 1, 2, 3, and 6 hydroxyl groups on the mannosamine skeleton are protected by acetyl groups (Ac). This design significantly enhances the hydrophobicity of the molecule, allowing it to efficiently penetrate the cell membrane and enter the cell. Once inside the cell, it is hydrolyzed by non-specific esterases, releasing active N-pentynoylmannosamine, thereby entering the sialic acid biosynthetic pathway.

• Pentynoyl tag: The 4-pentynoyl group introduced on the amino group is the core functional unit of the molecule. The terminal alkynyl group (-C≡CH) is a compact and stable bioorthogonal reaction handle that will not interfere with the normal metabolic process of cells. Sialic acids containing this alkynyl tag are ultimately incorporated into cell surface glycoproteins and glycolipids.

Main applications and advantages

Specific labeling and imaging of cell surface sialic acid

The most classic application of this molecule is as a metabolic precursor to fluorescently label sialic acid on the cell surface. After cellular uptake and metabolism to the corresponding sialic acid analog (SiaNAl), the analog is displayed at the end of the cell membrane glycoconjugate via a biosynthetic pathway. Subsequently, a fluorescent dye containing an azide group (such as Alexa Fluor 488-azide) is specifically linked to the alkynyl tag using a copper-catalyzed or strain-promoted azide-alkyne cycloaddition reaction, thereby achieving high-contrast and highly specific fluorescence imaging of sialic acid on the cell surface. This method avoids the possible non-specific binding of traditional antibody labels and can dynamically reflect the distribution of newly synthesized sialic acid.

Enrichment and identification of sialylated glycoproteome

At the proteomics level, this probe provides a key technology for the systematic discovery and identification of sialylated proteins. After metabolic labeling, click chemistry is also used to link the alkynyl tag to the azide group on a solid support (such as magnetic beads) to selectively enrich all newly synthesized sialylated glycoproteins. The enriched proteins can be analyzed by mass spectrometry to discover disease-related sialylation biomarkers, or to deeply study the dynamic changes of sialic acid modifications during specific physiological and pathological processes.

A powerful tool for studying sialic acid function and biosynthetic pathways

As a tool molecule, it makes it possible to intervene and study sialic acid function at the living cell level. By controlling its addition time and concentration, newly synthesized sialic acid within a certain period of time can be "marked" specifically in space and time for studying its turnover dynamics. In addition, by combining with technologies such as gene knockdown and inhibitor treatment, the functions of specific enzymes in the sialic acid biosynthetic pathway can be deeply explored, or the specific mechanisms of sialylation in key biological processes such as cell recognition, signal transduction, pathogen infection, and tumor immunity can be revealed.

Conclusion

N-(4'-pentynoyl)-1,2,3,6-O-tetraacetyl-D-mannosamine perfectly embodies the design concept of chemical biology tools: minimizing and functionally modifying natural molecules to achieve visualization, capture and analysis of complex life processes. It has greatly promoted the transition of glycoscience, especially sialic acid biology, from static description to dynamic functional research, laying a methodological foundation for basic biological discovery and the development of disease-related glycomarkers.

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