Abstract
Hydrogen Deuterium Exchange Mass Spectrometry (HDX-MS) is a powerful technique to monitor the intrinsic and conformational dynamics of proteins. Most HDX-MS experiments compare protein states (e.g. apoprotein vs liganded) and provide detailed information on differential dynamics between them obtained from multiple overlapping peptides. However, differential dynamics are difficult to compare across protein derivatives, oligomeric assemblies, homologues and samples treated under different buffer and protease conditions. A main reason is that peptide-based D-uptake differences do not inform on absolute intrinsic dynamics at the level of single aminoacyl residues. Such information is offered by protection factors, i.e. the position of the local equilibrium between the D-exchange-competent ‘open’ state and the non-exchanging ‘closed’ state. We present PyHDX, a software tool to calculate protection factors and Gibbs free energies typically within minutes from HDX-MS-derived peptide lists. PyHDX provides intrinsic information on the thermodynamics of protein dynamics at single-residue level. An interactive web interface further streamlines the process of transforming peptide lists to either coloured linear sequence maps or 3D structures of Gibbs free energies/protection factors.
Availability PyHDX source code is released under the MIT license and can be accessed at the project’s GitHub page.
Competing Interest Statement
The authors have declared no competing interest.
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