Comprehensive Internal Standards for Hydrogen-Deuterium Exchange Mass Spectrometry

Area of Science:

• Biochemistry
• Analytical Chemistry
• Structural Biology

Background:

• Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) is crucial for protein structure and dynamics analysis.
• Current HDX-MS methods face challenges in data comparability across different experimental setups and laboratories.

Purpose of the Study:

• To develop and validate novel internal exchange reporters (IERs) for direct measurement of HDX-MS reaction conditions.
• To enhance the accuracy and reproducibility of HDX-MS studies.

Main Methods:

• Design and synthesis of eight imidazolium-based IERs with a single discrete exchangeable site.
• Integration of IERs into HDX-MS workflows.
• Validation using comparative studies with offset reaction conditions (pH, deuterium content) on well-studied proteins.

Main Results:

• The novel IERs effectively sample exchange conditions over broad timescales (milliseconds to days).
• IERs exhibit favorable chromatographic properties for seamless integration.
• Demonstrated utility in comparative HDX-MS studies, enabling unambiguous referencing of conditions.

Conclusions:

• The developed IERs provide a robust internal standard for HDX-MS.
• This approach significantly improves cross-experiment comparability and data rigor.
• Enhanced HDX-MS models of protein dynamics are achievable with these new standards.