Characterization of intact mAb/SARS-CoV-2-S2 protein complexes by OmegaToF MS

Importance of the Topic

Protein complex analysis is critical for the development of therapeutic antibodies and vaccine design, especially for emerging pathogens such as SARS Cov 2

Study Objectives and Overview

The aim is to evaluate the capabilities of an extended mass range MALDI TOF mass spectrometer for direct detection of intact non covalent complexes formed by a monoclonal antibody targeting SARS Cov 2 S2 subunit and its antigen

Methodology and Instrumentation

Sample preparation involved mixing SARS Cov 2 S2 protein and anti SARS Cov 2 S2 monoclonal antibody at defined picomole concentrations, followed by MALDI matrix application and laser desorption ionisation with accumulation of multiple laser shots per spectrum

Used Instrumentation

• Extended range OmegaToF MALDI TOF mass spectrometer for high mass detection up to 1500 kDa

Main Results and Discussion

The intact antibody with a singly charged ion at approximately 148 kDa and the antigen at 87 kDa were detected with high signal to noise ratio. After cross linking, a complex ion at 343 kDa corresponding to a 2 to 1 stoichiometry of antigen to antibody was observed along with a modified antigen ion at 93 kDa. Overlay of control and cross linked spectra confirmed the high affinity interaction and excess of antigen prevented detection of a 1 to 1 complex

Benefits and Practical Applications

This approach enables rapid and direct analysis of large non covalent protein assemblies, supporting vaccine antigen screening, epitope mapping, and quality control in biopharmaceutical development

Future Trends and Opportunities

• Integration with separation techniques for complex mixture analysis
• Automation and higher throughput workflows
• Extension to larger assemblies such as virus like particles
• Advanced data processing using machine learning for deconvolution of high mass spectra

Conclusion

The OmegaToF MALDI TOF instrument extends the analytical mass range to enable reliable detection of intact antibody antigen complexes, offering a valuable tool for biopharma research and development