Work

Partial orientation retrieval of proteins from X-ray free-electron-laser induced explosions for single particle imaging

Year: 2025

Type: article

Abstract: Single Particle Imaging techniques at X-ray lasers have made significant strides, yet the challenge of determining the orientation of freely rotating molecules during delivery remains. In this study, we propose a novel approach to partially retrieve the relative orientation of proteins exposed to ultrafast X-ray pulses by analyzing the fragmentation patterns resulting from Coulomb explosions. We simulate these explosions for 85 proteins in the size range 100 - 4000 atoms using a hybrid Monte Carlo/Molecular Dynamics approach and capture the resulting ion ejection patterns on two virtual detectors. We exploit information from the explosion to infer orientations of proteins at the time of X-ray exposure. Our results demonstrate that partial orientation information can be extracted, particularly for larger proteins. We conclude that knowledge on ion data from X-ray laser induced explosions can directly provide the sample's relative orientation, complementary to traditional orientation-retrieval algorithms based on diffraction patterns.

Source: Scientific Reports

DOI: 10.1038/s41598-025-23827-w

Authors: Tomas André, Alfredo Bellisario, Emilano De Santis, Nicuşor Tîmneanu, Carl Caleman

Institutions: Uppsala University, University of Rome Tor Vergata, Center for Free-Electron Laser Science

Language: English

Topic: Advanced X-ray Imaging Techniques

Subfield: Radiation

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,690