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Published on: September 1, 2020
Characterization of Oxidative Modifications to Short Peptides Using Low Dose Rate X-Rays
Savannah Kidd1, Thomas McCarthy1, Simruthi Subramanian1
1Lawrence Berkeley National Laboratory, Molecular Foundry Division, Berkeley, CA 94720, USA.
Applied Sciences (Basel, Switzerland)
|July 8, 2026
Summary
This study demonstrates X-ray footprinting and mass spectrometry (XFMS) using low dose rate X-rays. The method characterizes oxidative peptide modifications and hydrogen peroxide production, offering insights into hydroxyl radical damage.
Area of Science:
- Structural Biology
- Biophysical Chemistry
- Mass Spectrometry
Background:
- X-ray footprinting and mass spectrometry (XFMS) is an established technique in structural biology.
- It relies on hydroxyl radicals produced by X-ray radiolysis to modify protein sidechains.
- High flux synchrotron sources minimize scavenging and secondary reactions.
Purpose of the Study:
- To demonstrate the feasibility of XFMS using low dose rate X-rays from a commercial instrument.
- To characterize oxidative modifications on short peptides.
- To quantify hydrogen peroxide production under low dose rate X-ray exposure.
Main Methods:
- Application of X-ray footprinting and mass spectrometry (XFMS).
- Utilized low dose rate X-rays from a commercial instrument.
- Analyzed short peptides under aerobic and low oxygen conditions.
Main Results:
- Successfully characterized oxidative modifications of +14, +16, and +32 Da on peptides.
- Quantified hydrogen peroxide production at various doses.
- Demonstrated feasibility of XFMS with a low dose rate X-ray source.
Conclusions:
- XFMS is feasible using low dose rate X-rays for peptide analysis.
- Provides fundamental data on hydroxyl radical-induced oxidative damage to peptides.
- Opens possibilities for XFMS applications with accessible X-ray sources.
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