Traceless Protein-Selective Glycan Labeling and Chemical Modification.

Area of Science:

• Glycoscience
• Chemical Biology
• Molecular Engineering

Background:

• Glycan editing is crucial for understanding biological processes and developing disease therapies.
• Precise control over glycoprotein modification (glyco-editing) remains a significant challenge.
• Maintaining the intact cellular glycan landscape post-editing is essential.

Purpose of the Study:

• To develop a versatile and traceless methodology for customizing glycoforms of targeted proteins.
• To achieve precise temporal and spatial control over glycan modification events.
• To minimize off-target glycan editing perturbations.

Main Methods:

• Development of a three-module, ligand-photocleavable linker-glycoenzyme (L-P-G) conjugate system.
• Utilizing chemical regulation via ligand-receptor interactions to initiate enzyme activity.
• Employing photoregulation through photoillumination to release the glycoenzyme for editing.

Main Results:

• Demonstrated ligand-dependent activation of glycoenzyme activity (RPG and SPG conjugates).
• Achieved precise temporal control of glycan editing via photolytic cleavage of the L-P-G conjugate.
• Observed altered target protein turnover and dimerization, highlighting the importance of native protein environments.

Conclusions:

• The developed methodology offers precise, traceless glycan modification of targeted glycoproteins.
• The combination of chemical and photoregulation ensures selective and controlled glyco-editing.
• Preserving the native physiological niche of proteins is critical during precise carbohydrate epitope modification.