BioSAXS

BioSAXS refers to the use of small-angle x-ray scattering (SAXS) to probe biologically-relevant systems, such as proteins (or protein aggregates) in solution.

Unlike crystallography or diffraction experiments, BioSAXS experiments typically do not generate distinct Bragg peaks or rings. Instead, a smooth decay of scattering intensity is observed at small scattering angles (which may look like diffuse scattering). However, with appropriate modeling, the specific form of this intensity decay can be fit in order to extract parameters of physical interest, including:

• Radius of gyration, or molecular weight, of macromolecules (including proteins)
• Particle shape (at low resolution)
• Inter-particle distances
• Aggregation or conformational state of macromolecules (degree of folding, denaturation, disorder)

References

• Nielsen, S. S., Moller, M. & Gillilan, R. E. High-throughput biological small-angle X-ray scattering with a robotically loaded capillary cell J. Appl. Cryst. 2012, 45, 213-223. doi: 10.1107/S0021889812000957
• D. A. Jacques, J. M. Guss, D. I. Svergun and J. Trewhella Publication guidelines for structural modelling of small-angle scattering data from biomolecules in solution Acta Cryst. 2012 D68, 620-626 doi: 10.1107/S0907444912012073
• Kevin N. Dyer, Michal Hammel, Robert P. Rambo, Susan E. Tsutakawa, Ivan Rodic, Scott Classen, John A. Tainer, Greg L. Hura High-Throughput SAXS for the Characterization of Biomolecules in Solution: A Practical Approach Methods in Molecular Biology 2014, 1091, 245-258 10.1007/978-1-62703-691-7_18
• Soren Skou, Richard E Gillilan & Nozomi Ando Synchrotron-based small-angle X-ray scattering of proteins in solution Nature Protocols 2014, 9, 1727-1739 doi: 10.1038/nprot.2014.116
• Lachlan W. Casey, Alan E. Mark and Bostjan Kobe Small-Angle X-Ray Scattering for the Discerning Macromolecular Crystallographer Australian Journal of Chemistry 2014, 67 (12) 1786-1792 doi: 10.1071/CH14396
• Bente Vestergaarda and Zehra Sayersb Investigating increasingly complex macromolecular systems with small-angle X-ray scattering IUCrJ 2014, 1 (6), 523-529 doi: 10.1107/S2052252514020843

See Also

• CHESS guide to BioSAXS