New Horizons for biomolecular solution small- and wide-angle X-ray scattering

U-Ser Jeng^1,2*

¹Scientific Research Divsison, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
²Department of Chemical Engineering, , National Tsing Hua University, Hsinchu, Taiwan

* Presenter:U-Ser Jeng, email:usjeng@nsrrc.org.tw

Recent fast and rich developments in the instrumentation and data analysis of synchrotron small-angle X-ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular tool in structural biology. In this presentation in the annual meeting of Taiwan Physics Society, I will report an advanced endstation recently developed at the beamline 13A of the Taiwan Photon Source for biological small- and wide-angle X-ray scattering (SAXS-WAXS or SWAXS). The new instrument features with an in-vacuum SWAXS detecting system comprising two mobile Eiger detectors X 9M/1M and an online size-exclusion chromatography system incorporated with several optical probes, including UV-vis absorption, refractive index spectrometer, multi-angle laser light scattering, and dynamic light scattering. The performance of the endstation is illustrated with the impressive SWAXS data collected for several model proteins in solution, covering a scattering vector range wider than 0.01- 2.0 Å-1. The amazing matching of the crystal-model fittings to the data indicate high fidelity of the solution structures of the proteins to their crystalline forms, and reveal further subtle hydration-dependent local details of the protein in different hydration environments. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.

Keywords: small-angle X-ray scattering, biomolecular solution scattering, UV-Vis absorption and refractive index, online size-exclusion-chromatography, protein solution structure