Carbohydrate molecular weight profiling, sequence, linkage, and branching data: ES-MS and CID

Area of Science:

• Analytical Chemistry
• Glycobiology
• Mass Spectrometry

Background:

• Understanding the complex structures of carbohydrates like glycolipids and glycoprotein glycans is crucial in various biological processes.
• Existing analytical methods often face challenges in achieving high specificity and sensitivity for detailed glycan analysis.

Purpose of the Study:

• To present and evaluate a suite of mass spectrometry-based strategies for comprehensive carbohydrate structure elucidation.
• To improve the characterization of isomeric glycans, including sequence, linkage, and branching patterns.

Main Methods:

• Utilizing periodate oxidation for enhanced glycan specificity.
• Employing methylation to increase sensitivity and information content in collision-induced dissociation (CID) spectra.
• Leveraging electrospray ionization (ESI) for soft ionization and CID for structural detail.
• Combining derivatization, solvent extraction, and ESI-CID-MS for sensitive analysis.

Main Results:

• The integrated approach provides detailed sequence, linkage, and branching information for glycans.
• Derivatization enhances product cleanup and sensitivity during electrospray ionization.
• Contrasting profiles from oxidation/reduction followed by methylation aid in corroborating glycan structure and identifying isobaric elements.
• ESI-CID-MS enables structural elucidation at the low-picomole level.

Conclusions:

• The presented mass spectrometry strategies offer a powerful toolkit for detailed carbohydrate structural analysis.
• Further advancements in ionization techniques and mass analyzers are expected to enhance versatility in glycan structural determination.
• This methodology is particularly valuable for the structural elucidation of complex glycolipids and glycoprotein glycans.