Work

Small-angle X-ray scattering profile calculation for high-resolution models of biomacromolecules

Year: 2025

Type: article

Abstract: We introduce a new approach to calculating small-angle X-ray scattering (SAXS) profiles from high-resolution atomic structures, which is realized in the open-source software AUSAXS. We employ an efficient implementation of the Debye equation, incorporating both accurate excluded volume models and a novel hydration shell model based on explicit dummy atoms. Two new excluded volume models are presented: (i) a simple, heterogeneous equivalent atom model, and (ii) a grid-based model. The two approaches reduce the risk of overfitting by either eliminating fitting parameters or introducing a safer volume scaling method. These models are compared with the traditional Gaussian sphere method, which is widely used in existing software. The comparisons reveal significant shortcomings in previously accepted methods, suggesting they may be more prone to overfitting than previously thought. This underscores the importance of a well tested and openly accessible baseline implementation like AUSAXS. AUSAXS is freely available at https://github.com/AUSAXS/AUSAXS.

Source: Journal of Applied Crystallography

DOI: 10.1107/s160057672500562x

Authors: Kristian Lytje, Jan Skov Pedersen

Institution: Aarhus University

Language: English

Topic: Enzyme Structure and Function

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $5,110

Funder: Danmarks Frie Forskningsfond