Surreal illustration of glycan chains with glowing sialic acid molecules, symbolizing precision in glycan analysis.

Unlock Glycan Analysis: Acing Sialic Acid Linkage with Advanced Techniques

Author's portrait.
Soraya Malik in Science & Nature June 2025 • 4 min read.

"New research optimizes LC-MS and MS/MS methods for enhanced accuracy in glycan structure determination, paving the way for breakthroughs in disease research and personalized medicine."


Glycans, complex sugar molecules, are vital players in a host of biological processes, from cell communication to immune responses. Sialic acids (Sias), often found at the outer ends of glycan chains, act as key identifiers, influencing how cells interact and respond to their environment. The arrangement, or linkage, of these sialic acids is critical, dictating their function. Understanding these linkages is paramount for decoding the language of cells and developing targeted therapies.

Traditional methods for analyzing glycan structures often fall short when it comes to accurately determining sialic acid linkages. These methods can be cumbersome, time-consuming, and may not provide the detailed information needed to fully characterize complex glycans. This is where advanced analytical techniques, such as liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (MS/MS), come into play.

Recent research has focused on refining LC-MS and MS/MS methods to provide a more robust and reliable approach for analyzing sialic acid linkages. These optimized techniques promise to unlock new insights into glycan function, with broad implications for disease research, diagnostics, and personalized medicine.

What's the Big Deal About Sialic Acid Linkages?

Surreal illustration of glycan chains with glowing sialic acid molecules, symbolizing precision in glycan analysis.

Sialic acids (Sias) are involved in various biological and pathological processes, and are often found attached to non-reducing ends of glycans through either α2,3- or α2,6-linkages. Quantitative analysis of glycan structures with these linkage isoforms by liquid chromatography-mass spectrometry (LC-MS) requires more advanced processes. This study establishes a linkage-specific two-step alkylamidation method for N-glycans.

Carboxyl groups of α2,3- and α2,6-linked Sia are derivatized with two kinds of alkylamines with different mass values in a linkage-specific manner, allowing products to be easily distinguished. The reaction efficiencies for di-, tri-, and tetra-sialyl PA-N-glycans were >94%, with few by-products. Mixtures of 2-aminopyridine (PA)-tagged N-glycans from human α1-acid glycoprotein were subjected to the method, and products were analyzed by LC-MS and MS/MS, and simultaneously monitored with a fluorescence detector.

  • High-Throughput Analysis: Optimizing methods for quick and efficient processing of samples.
  • Maximized Glycan Analysis: Ensuring a broad range of glycans, including complex and heterogeneous types, can be analyzed.
  • Linkage-Specific Alkylamidation: A precise method to modify sialylated glycans, enhancing the accuracy of linkage identification.
The relative content of Siaα2-3Gal and Siaα2-6Gal was estimated from the integrated fluorescence intensity of each peak. Moreover, MS/MS data clearly indicated characteristic B-ion fragments of N-glycan branches, such as the sialyl Lex sequence, with Sia linkage-specific alkylamidation, suggesting that this method also provides useful information of branch sequences. The method can enable high-throughput analysis and maximizing the analysis of glycans from various types of samples, including highly heterogeneous glycans.

The Future of Glycan Analysis

As analytical techniques continue to advance, our ability to decipher the complexities of glycan structures will only improve. These refined methods hold immense potential for advancing our understanding of biological processes, diagnosing diseases, and developing targeted therapies. From personalized medicine to novel diagnostic tools, the future of glycan analysis is bright, promising new insights into the intricate world of cellular interactions.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

1

What are glycans and why are they important?

Glycans are complex sugar molecules that play vital roles in numerous biological processes. They are involved in cell communication and immune responses. The arrangement, or linkage, of these sialic acids is critical, dictating their function. Understanding these linkages is paramount for decoding the language of cells and developing targeted therapies.

2

How are sialic acids relevant to glycan analysis, and what is their function?

Sialic acids (Sias) are often found at the outer ends of glycan chains and act as key identifiers, influencing how cells interact and respond to their environment. The arrangement, or linkage, of these sialic acids is critical, dictating their function. Specifically, the α2,3- and α2,6-linkages are the focus of advanced analytical techniques. Understanding these linkages is essential for decoding the language of cells and developing targeted therapies.

3

What are the limitations of traditional methods in analyzing glycan structures, particularly regarding sialic acid linkages?

Traditional methods often struggle to accurately determine sialic acid linkages. These methods can be cumbersome and time-consuming. They may not provide the detailed information needed to fully characterize complex glycans. Advanced methods, such as liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (MS/MS), offer more robust and reliable approaches.

4

How do LC-MS and MS/MS techniques improve glycan analysis, and what is the role of linkage-specific alkylamidation?

LC-MS and MS/MS techniques provide a more robust and reliable approach for analyzing sialic acid linkages. The linkage-specific alkylamidation method is a precise method to modify sialylated glycans, enhancing the accuracy of linkage identification. This method allows for the differentiation of α2,3- and α2,6-linked Sias, critical for accurate glycan structure determination and understanding their biological roles. This approach enables high-throughput analysis and maximizes the analysis of glycans from various types of samples, including highly heterogeneous glycans.

5

What is the potential impact of advanced glycan analysis on disease research and personalized medicine?

Advanced glycan analysis, particularly through the use of optimized LC-MS and MS/MS methods, holds immense potential for disease research and personalized medicine. By improving our understanding of glycan structures and their linkages, we can gain new insights into biological processes, diagnose diseases more effectively, and develop targeted therapies. This leads to the potential for novel diagnostic tools and personalized medicine approaches that are tailored to individual patient needs.

Newsletter Subscribe

Subscribe to get the latest articles and insights directly in your inbox.