Site-Specific Hydrogen Deuterium Exchange Difference Mass Spectrometry Measurements for Ligand Binding

Area of Science:

• Biochemistry
• Analytical Chemistry
• Structural Biology

Background:

• Conventional bottom-up Hydrogen Deuterium Exchange Mass Spectrometry (HDX-MS) offers peptide-level structural resolution, valuable for drug development.
• Current methods for site-specific (amino acid-resolved) HDX-MS, such as Electron Capture Dissociation (ECD) and Electron Transfer Dissociation (ETD), suffer from low efficiency and sensitivity losses due to deuterium scrambling prevention.

Purpose of the Study:

• To apply a novel, high-efficiency ECD method with zero scrambling to differential HDX-MS experiments in the context of ligand binding.
• To demonstrate the acquisition of significantly more detailed structural information at the amino acid level compared to traditional peptide-level analyses.

Main Methods:

• Utilized a recently developed method for high-efficiency Electron Capture Dissociation (ECD) with zero deuterium scrambling.
• Performed differential HDX-MS experiments focusing on ligand binding interactions.
• Analyzed structural dynamics at single amino acid resolution.

Main Results:

• Successfully applied high-efficiency, zero-scrambling ECD to ligand binding differential HDX-MS experiments.
• Demonstrated the practical feasibility of amino acid-level HDX-MS for studying ligand interactions.
• Revealed substantial additional structural information obtainable through site-specific measurements.

Conclusions:

• The developed ECD method overcomes the sensitivity limitations of previous site-specific HDX-MS techniques.
• Amino acid-level HDX-MS analysis provides a wealth of information crucial for understanding drug-target interactions in drug development.
• This advancement significantly enhances the utility of HDX-MS in pharmaceutical research.