HX-Express

HX-Express analyzes hydrogen/deuterium exchange (HDX) mass spectrometry data to quantify deuterium uptake and resolve overlapped mass envelopes for studies of protein conformational dynamics.

Key Features:

• Semi-Automated Data Analysis: Accepts peak inputs as x,y lists of m/z versus intensity or imports data from Waters MassLynx to expedite peak-based analysis.
• Visualization and Quality Control: Generates deuterium uptake plots and peak width plots and preserves numeric records for quality assessment.
• Enhanced Data Processing Algorithms: Employs binomial distribution fitting combined with asymmetric linear squares regression to calculate deuterium content in noisy or overlapping mass envelopes.
• Improved Sequence Coverage and Precision: Demonstrated an 11% increase in sequence coverage in a test data set of HIV Env gp140, enabling exchange data acquisition for an additional 42 peptides and improving precision of deuterium uptake measurements across examined peptides.
• Efficient Deconvolution: Deconvolutes bimodal mass envelopes and resolves EX1 kinetic signatures in complex spectra.

Scientific Applications:

• Protein Dynamics and Folding: Quantifies site-resolved deuterium uptake for studies of protein conformational changes and folding pathways using HDX-MS.
• Protein–Protein and Protein–Ligand Interactions: Maps differential deuterium incorporation to identify interaction interfaces and binding-induced conformational changes.
• Complex Biological Samples: Resolves overlapped and bimodal mass envelopes to enable HDX analysis in complex proteomic contexts such as viral envelope proteins (e.g., HIV Env gp140).

Methodology:

Accepts m/z versus intensity inputs as x,y lists or MassLynx imports; performs binomial distribution fitting with asymmetric linear squares regression to calculate deuterium content; generates deuterium uptake and peak width plots; deconvolutes bimodal mass envelopes and EX1 kinetic signatures.