UV Photodissociation Mass Spectrometry Accurately Localize Sites of Backbone Deuteration in Peptides

摘要

Hydrogen/deuterium exchange mass spectrometry (HDX-MS) is now a routinely used technique to inform on protein structure, dynamics, and interactions. Localizing the incorporated deuterium content on a single residue basis increases the spatial resolution of this :technique enabling detailed structural analysis. Here, we investigate the use of ultraviolet photodissociation (UVPD) at 213 nm to measure deuterium levels at single residue resolution in HDX-MS experiments. Using a selectively labeled peptide, we show that UVPD occurs without H/D scrambling as the peptide probe accurately retains its solution-phase deuterium labeling pattern. Our results indicate that UVPD provides an attractive alternative. to electron mediated dissociation for increasing the spatial resolution of the HDX-MS experiment, capable of yielding high fragmentation efficiency, high fragment ion diversity, and low precursor ion charge-state dependency.