Protein eXplosion Imaging (PXI): Protein Structures from Laser-Driven Explosions
Year: 2026
Type: preprint
Abstract: We investigate the structural information retained in the distribution of explosion ion trajectories from proteins subjected to strong ionization. Using molecular-dynamics simulations and machine-learning analysis benchmarked against an analytical approach, we show that low-resolution structural information can be retrieved from the explosion distributions alone. An ensemble of convolutional neural networks trained on simulated spherical ion maps recovers the radius of gyration and the three semi-axes of an ellipsoidal molecular envelope with prediction errors of 1.2 Å and 1.5 Å, respectively, while an analytical ellipsoid charge model returns similar estimates and performs best for globular structures. We further investigate how higher-level structural information and symmetries can be extrapolated from ion measurements. This study supports the viability for structural determination of single proteins without large-scale X-ray facilities.
Source: PubMed
DOI: 10.11577/3695380
Authors: Bellisario, Alfredo, André, Tomas, Caleman, Carl, Tîmneanu, Nicuşor
Institutions: Uppsala University, Center for Free-Electron Laser Science
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Funders: Bundesministerium für Bildung und Forschung, Vetenskapsrådet, Uppsala Universitet, Röntgen-Ångström Cluster, National Institutes of Health, University of California, San Francisco, Deutsches Elektronen-Synchrotron, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases
Awards: ReFIXED: Resonant and Fluorescent Incoherent X-ray Emission and Diffraction, G5404260858, G5853244934, Solving the orientation problem in Single Particle Imaging using XFEL, G712881263, G7569742080, G7694170058, SAXFELS, G869003648, G8760597890, NAISS, ChimeraX -- Next Generation Visualization and Analysis Software for Multiscale Modeling, FIXED: Fluorescent Incoherent X-ray Emission and Diffraction to determine protein structures
OpenAlex ID: W7212133461