NEW FEATURES IN BIOINFORMATICS SOFTWARE FOR AUTOMATED PROCESSING OF HDX MS DATA

Importance of the Topic

Hydrogen/deuterium exchange mass spectrometry (HDX-MS) offers detailed insight into protein dynamics, conformational changes and interactions under different conditions. This method is widely used in structural biology, biopharmaceutical development, and quality control, as it reveals solvent accessibility and stability of protein domains.

Objectives and Study Overview

This work introduces DynamX 3.0, a bioinformatics software for automated processing of HDX-MS data at intact protein, peptide and fragment levels. The study applies the software to analyze structural stability of human IgG2 under denaturing conditions, demonstrating new visualization features and streamlined workflows.

Methodology and Instrumentation Used

• Sample Preparation: Human IgG2 (Denosumab) at 1 mg/ml in 200 mM phosphate buffer, pH 6.8, with 1.0 M guanidine HCl, incubated at 25 °C for 18 h.
• HDX Labeling: Reaction with D2O buffer at 25 °C for time points from 0.5 to 120 min, followed by quenching at 0 °C, pH 2.5.
• Data Acquisition: HDX-MS data collected with support for ion mobility separation and electron transfer dissociation (ETD).
• Data Analysis: Automated selection and processing of spectra, peptide identification and deuterium uptake calculation handled by DynamX 3.0 software.

Main Results and Discussion

• Intact Protein Analysis: Deuterium uptake curves compare native and denatured IgG2, revealing increased exchange rates under denaturing conditions.
• Peptide-Level Mapping: Over 95% sequence coverage achieved for heavy and light chains, with 145 and 68 peptides identified respectively.
• Visualizations: Heat maps transferred to PyMOL highlight regional deuteration differences; coverage maps and butterfly plots illustrate uptake kinetics and structural perturbations.
• Domain Stability Ranking: CH2, CH1 and CL domains show varying degrees of unfolding, while CH3 remains the most stable region.

Benefits and Practical Applications

DynamX 3.0 accelerates HDX-MS workflows by automating data processing across multiple levels, enhancing reproducibility and reducing manual analysis time. Advanced visualization tools enable rapid identification of structural differences, supporting biotherapeutic development, protein engineering and conformational studies.

Future Trends and Potential Applications

• Integration of machine learning for automated region selection and pattern recognition.
• Cloud-based HDX-MS data pipelines for collaborative analysis and data storage.
• Coupling HDX-MS with complementary structural methods such as cryo-EM and NMR for comprehensive modeling.
• Expansion of ETD and ion mobility workflows to probe larger proteins and complex assemblies.

Conclusion

DynamX 3.0 delivers a robust platform for automated HDX-MS data analysis, offering comprehensive workflows from intact protein to fragment level. The case study on IgG2 denaturation illustrates its capability to rank domain stability and visualize structural changes, empowering researchers in structural biology and biopharma.

References

• Fang J, Yu YQ, Fadgen K, Eggerton M, Lawler R, Chakraborty A. New Features in Bioinformatics Software for Automated Processing of HDX MS Data. Waters Corporation; 2015.