Related Experiment Video
Updated: Jun 27, 2026
08:16
Visualizing Intracellular Sialylation with Click Chemistry and Expansion Microscopy
Published on: February 7, 2025
Organelle-directed metabolic glycan labeling
Shixiong Wen1, Yilong Shi2, Enkang Zhang3
1Academician Workstation of Immune Cell Signal Transduction, School of Basic Medicine, Chongqing Medical University, Chongqing, P.R. China.
Methods in Enzymology
|June 25, 2026
Summary
Organelle-specific metabolic glycan labeling (OMGL) allows researchers to target and label the inner lysosomal membrane. This technique enables optical tracking of stressed lysosomes during exocytosis and cell death.
Area of Science:
- Biochemistry
- Cell Biology
- Chemical Biology
Background:
- Metabolic glycan labeling (MGL) modifies cell surfaces by bioorthogonal labeling of abiotic sugars on the glycocalyx.
- Lysosomal membranes, like plasma membranes, are densely covered with glycans.
- Current MGL methods primarily focus on cell surface modifications.
Purpose of the Study:
- To develop organelle-specific MGL (OMGL) for selective labeling of the lysosomal inner membrane.
- To enable optical tracking of stressed lysosomes using OMGL.
- To overcome limitations of conventional probes in stressed lysosomes.
Main Methods:
- Metabolic incorporation of 9-azidosialic acid (AzSia) into the cellular glycome.
- Staining cells with dibenzocyclooctyne (DBCO)-bearing lyso-probes that accumulate in lysosomes via acidotropic effect.
- Bioorthogonal ligation of lyso-probes with AzSia on the lysosomal inner membrane.
Main Results:
- OMGL successfully achieved selective labeling of the lysosomal inner membrane, sparing the cell surface.
- The developed OMGL method enabled optical tracking of stressed lysosomes.
- OMGL overcomes probe dissipation issues in stressed lysosomes.
Conclusions:
- OMGL is a novel technique for organelle-specific glycan labeling within lysosomes.
- This method facilitates the study of lysosomal dynamics in cellular processes like exocytosis and cell death.
- OMGL provides a robust tool for investigating lysosome function and dysfunction.
Related Concept Videos
01:24Oligosaccharide Assembly
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
01:25Protein Glycosylation
Glycosylation, the most common post-translational modification for proteins, serves diverse functions. Adding sugars to proteins makes the proteins more resistant to proteolytic digestion. Glycosylated proteins can act as markers and receptors to promote cell-cell adhesion. Additionally, they have many essential quality control functions in the cell, such as correct protein folding and facilitating transport of misfolded proteins to the cytosol, which can be degraded.
Glycosylation occurs in...
Glycosylation occurs in...