Time-resolved scattering methods for biological samples at the CoSAXS beamline, MAX IV Laboratory

Summary, in English

CoSAXS is a state-of-the-art SAXS/WAXS beamline exploiting the high brilliance of the MAX IV 3 GeV synchrotron. By coupling advances in sample environment control with fast X-ray detectors, millisecond time-resolved scattering methods can follow structural dynamics of proteins in solution. In the present work, four sample environments are discussed. A sample environment for combined SAXS with UV–vis and fluorescence spectroscopy (SUrF) enables a comprehensive understanding of the time evolution of conformation in a model protein upon acid-driven denaturation. The use of microfluidic chips with SAXS allows the mapping of concentration with very small sample volumes. For highly reproducible sequences of mixing of components, it is possible using stopped-flow and SAXS to access the initial effects of mixing at 2 millisecond timescales with good signal to noise to allow structural interpretation. The intermediate structures in a protein are explored under light and temperature perturbations by using lasers to “pump” the protein and SAXS as the “probe”. The methods described demonstrate that features at low q, corresponding to cooperative motions of the atoms in a protein, could be extracted at millisecond timescales, which results from CoSAXS being a highly-stable, low background, dedicated SAXS beamline.

• Author: Fátima Herranz-Trillo; Henrik Vinther Sørensen; Cedric Dicko; Javier Pérez; Samuel Lenton; Vito Foderà; Anna Fornell; Marie Skepö; Tomás S. Plivelic; Oskar Berntsson; Magnus Andersson; Konstantinos Magkakis; Fredrik Orädd; Byungnam Ahn; Roberto Appio; Jackson Da Silva; Vanessa Da Silva; Marco Lerato; Ann E. Terry
• Department/s: MAX IV, CoSAXS; NanoLund: Centre for Nanoscience; LU Profile Area: Light and Materials; Computational Chemistry; MAX IV Laboratory; MAX IV, Diffraction and scattering; LTH Profile Area: Food and Bio; LTH Profile Area: Engineering Health; Pure and Applied Biochemistry; eSSENCE: The e-Science Collaboration; LINXS - Institute of advanced Neutron and X-ray Science; LTH Profile Area: Nanoscience and Semiconductor Technology; MAX IV, FemtoMAX; MAX IV, Diffraction and scattering; MAX IV, Imaging
• Publishing year: 2024-01
• Language: English
• Pages: 245-296
• Publication/Series: Methods in Enzymology
• Volume: 709
• Links: http://dx.doi.org/10.1016/bs.mie.2024.10.019
• Document type: Book chapter
• Publisher: Academic Press
• Topic: Subatomic Physics
• Keywords: BioSAXS; CoSAXS; Fluorescence; Microfluidics; SAXS; Stopped-flow; Time-resolved SAXS; Time-resolved X-ray solution scattering; TR-XSS; UV–vis
• Status: Published
• ISBN/ISSN/Other: ISSN: 1557-7988; ISSN: 0076-6879; ISBN: 9780443314568