Resonant Soft X-Ray Scattering Provides Protein Structure with Chemical Specificity

Dan Ye; Thinh P Le; Brooke Kuei; Chenhui Zhu; Peter H Zwart; Cheng Wang; Enrique D Gomez; Esther W Gomez

doi:10.1016/j.str.2018.07.018

Resonant Soft X-Ray Scattering Provides Protein Structure with Chemical Specificity

Structure. 2018 Nov 6;26(11):1513-1521.e3. doi: 10.1016/j.str.2018.07.018. Epub 2018 Sep 13.

Authors

Dan Ye¹, Thinh P Le¹, Brooke Kuei², Chenhui Zhu³, Peter H Zwart⁴, Cheng Wang⁵, Enrique D Gomez⁶, Esther W Gomez⁷

Affiliations

¹ Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
² Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
³ Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
⁴ Berkeley Center for Structural Biology, Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA; The Center for Advanced Mathematics for Energy Research Applications, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
⁵ Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. Electronic address: cwang2@lbl.gov.
⁶ Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA; Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: edg12@psu.edu.
⁷ Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: ewg10@psu.edu.

Abstract

We introduce resonant soft X-ray scattering (RSoXS) as an approach to study the structure of proteins and other biological molecules in solution. Scattering contrast calculations suggest that RSoXS has comparable or even higher sensitivity than hard X-ray scattering because of contrast generated at the absorption edges of constituent elements, such as carbon and oxygen. Here, we demonstrate that working near the carbon edge reveals the envelope function of bovine serum albumin, using scattering volumes of 10^-5 μL that are multiple orders of magnitude lower than traditional scattering experiments. Furthermore, tuning the X-ray energy within the carbon absorption edge provides different signatures of the size and shape of the protein by revealing the density of different types of bonding motifs within the protein. The combination of chemical specificity, smaller sample size, and enhanced X-ray contrast will propel RSoXS as a complementary tool to existing techniques for the study of biomolecular structure.

Keywords: NEXAFS; RSoXS; SAXS; envelope function; protein structure; small-angle scattering; soft X-rays.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Cattle
Models, Molecular
Protein Conformation
Serum Albumin, Bovine / chemistry*
X-Ray Diffraction / methods*

Substances

Serum Albumin, Bovine

Abstract

Publication types

MeSH terms

Substances

Grants and funding