title: Diffracted X-ray tracking for monitoring intramolecular motion in individual protein molecules using broad band X-ray.
abstract: Diffracted X-ray tracking (DXT) enables the tilting and twisting motions of single protein molecules to be monitored with micro- to milliradian resolution using a highly brilliant X-ray source with a wide energy bandwidth. We have developed a technique to monitor single molecules using gold nanocrystals attached to individual protein molecules using the BL28B2 beamline at SPring-8. In this paper we present the installation of a single toroidal X-ray mirror at BL28B2 to focus X-rays in an energy range of 10-20 keV (ΔE/E = 82% for an X-ray with a wide energy bandwidth). With this beamline we tracked diffraction spots from gold nanocrystals over a wide angle range than that using quasi-monochromatic X-rays. Application of the wide angle DXT technique to biological systems enabled us to observe the on-site motions of single protein molecules that have been functionalized in vivo. We further extend the capability of DXT by observing the fractional tilting and twisting motions of inner proteins under various conditions. As a proof of this methodology and to determine instrumental performance the intramolecular motions of a human serum albumin complex with 2-anthracenecarboxylic acid was investigated using the BL28B2 beamline. The random tilting and twisting intramolecular motions are shown to be directly linked to the movement of individual protein molecules in the buffer solution.
authors.affiliation: Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561, Japan.
authors.forename: Kouhei
authors.initials: K
authors.lastname: Ichiyanagi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sekiguchi
authors.forename: Masato
authors.initials: M
authors.lastname: Hoshino
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kajiwara
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hoshisashi
authors.forename: Jae-won
authors.initials: JW
authors.lastname: Chang
authors.forename: Maki
authors.initials: M
authors.lastname: Tokue
authors.forename: Yufuku
authors.initials: Y
authors.lastname: Matsushita
authors.forename: Masaki
authors.initials: M
authors.lastname: Nishijima
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Inoue
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Senba
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Ohashi
authors.forename: Noboru
authors.initials: N
authors.lastname: Ohta
authors.forename: Naoto
authors.initials: N
authors.lastname: Yagi
authors.forename: Yuji C
authors.initials: YC
authors.lastname: Sasaki
mesh_terms: D000873:Anthracenes / Q000378:metabolism; D002264:Carboxylic Acids / Q000378:metabolism; D006801:Humans; D009068:Movement; D012709:Serum Albumin / Q000378:metabolism*; D014961:X-Ray Diffraction / Q000295:instrumentation / Q000379:methods*
chemical_list: C476641:2-anthracenecarboxylate; D000873:Anthracenes; D002264:Carboxylic Acids; D012709:Serum Albumin