RAPID PREPARATION OF RELEASED N-GLYCANS FOR HILIC ANALYSIS USING A NOVEL FLUORESCENCE AND MS-ACTIVE LABELING REAGENT

Significance of the topic

Rapid and sensitive analysis of released N-glycans is essential across biopharmaceutical development, quality control and fundamental glycomics research. Conventional preparation techniques often require lengthy incubations, multiple manual steps and compromise between fluorescent and MS detection. A streamlined workflow that delivers high throughput, reproducible glycan release, rapid labeling and enhanced detection would substantially improve analytical efficiency and data quality in laboratories performing HILIC-FLR-MS profiling.

Objectives and study overview

The study aimed to develop and validate a novel sample preparation strategy for released N-glycans that combines:

• Rapid enzymatic deglycosylation of glycoproteins.
• A new fluorescence- and MS-active labeling reagent with fast kinetics.
• An efficient HILIC µElution SPE cleanup to streamline workflow.
• Compatibility with high-resolution HILIC-FLR-MS analysis.

The goal was to achieve complete glycoprotein deglycosylation, quantitative glycan recovery, and markedly improved fluorescence and MS response factors in under 30 minutes.

Methodology and instrumentation used

The GlycoWorks RapiFluor-MS N-Glycan Kit integrated three key reagents:

• Rapid PNGase F and RapiGest SF surfactant for complete deglycosylation in ~10 minutes.
• RapiFluor-MS labeling reagent—an NHS-carbamate rapid tag with quinoline fluorophore and tertiary amine—to derivatize glycosylamines in 5 minutes.
• HILIC µElution SPE using aminopropyl silica sorbent for cleanup without dry-down.

Instrument platforms and conditions:

• LC: ACQUITY UPLC H-Class Bio System, Glycan BEH Amide 1.7 µm, 2.1×50 mm, 60 °C, 0.4 mL/min; gradient of 50 mM ammonium formate pH 4.4 and ACN.
• Fluorescence detection: Ex/Em 265/425 nm for RapiFluor-MS; comparative settings for Instant ABTM and 2-AB.
• MS: Waters Synapt G2-S HDMS, ESI+, TOF (~20 000 resolution), capillary 3.0 kV, cone 80 V, source 120 °C, desolvation 350 °C, scan 500–2500 m/z.

Main results and discussion

• Labeling kinetics: Complete derivatization of released N-glycans in 5 minutes under ambient aqueous conditions, forming stable urea linkages.
• Detection sensitivity: For the FA2 glycan from a monoclonal antibody, RapiFluor-MS enhanced fluorescence by 2-fold and MS base-peak intensity by ~780-fold versus Instant AB; significant improvements over conventional 2-AB labeling were also demonstrated.
• Deglycosylation performance: Rapid PNGase F with RapiGest SF achieved unbiased, complete glycan release across diverse glycoproteins in ~10 minutes, confirmed by SDS-PAGE gel shift assays.
• SPE cleanup: Aminopropyl HILIC µElution plate provided quantitative recovery and reproducible relative glycan abundances (neutral to tetrasialylated) without sample drying; one- and two-pass SPE gave comparable profiles.
• Workflow speed: End-to-end sample preparation (deglycosylation, labeling, cleanup) completed in ~30 minutes, markedly reducing total analysis time compared to multi-hour protocols.

Benefits and practical applications of the method

• High throughput: Ultra-fast glycan release and derivatization streamline batch analysis in QC and process development.
• Enhanced sensitivity: Dramatically improved fluorescence and MS response factors enable low-level glycan detection and quantitation.
• Simplicity: Minimal hands-on time, no solvent evaporations, and a robust SPE cleanup facilitate reproducible workflows.
• Versatility: Applicable to a wide range of glycoprotein sources, including monoclonal antibodies and serum glycoproteins.

Future trends and potential applications

• Automated sample preparation: Integration with liquid-handling platforms for further throughput gains.
• Expanded reagent development: Novel tags targeting specific glycan features (e.g., sialic acid linkages) for deeper structural insights.
• AI-driven data analysis: Machine-learning algorithms to interpret complex glycan profiles and predict biological impacts.
• Clinical biomarker discovery: Sensitive glycomics workflows for disease diagnostics and therapeutic monitoring.

Conclusion

The RapiFluor-MS N-Glycan Kit offers a unified solution for rapid, high-sensitivity HILIC-FLR-MS analysis of released N-glycans. By combining accelerated deglycosylation, ultrafast fluorescent/MS tagging and robust SPE cleanup, this workflow dramatically improves throughput and detection limits while ensuring accurate glycan profiling for biopharmaceutical and glycomics applications.

References

1. Mechref Y, Hu Y, Desantos-Garcia JL, Hussein A, Tang H. Quantitative glycomics strategies. Mol Cell Proteomics. 2013;12(4):874–884.
2. Cook KS, Bullock K, Sullivan T. Development and qualification of an antibody rapid deglycosylation method. Biologicals. 2012;40(2):109–117.
3. Klapoetke S, Zhang J, Becht S, Gu X, Ding X. The evaluation of a novel approach for the profiling and identification of N-linked glycan with a procainamide tag by HPLC with fluorescent and mass spectrometric detection. J Pharm Biomed Anal. 2010;53(3):315–324.