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Fujiwara, Satoru*; Matsuo, Tatsuhito*; Sugimoto, Yasunobu*; Shibata, Kaoru
Journal of Physical Chemistry Letters (Internet), 10(23), p.7505 - 7509, 2019/12
Times Cited Count：4 Percentile：21.85(Chemistry, Physical)Characterization of the dynamics of disordered polypeptide chains is required to elucidate the behavior of intrinsically disordered proteins and proteins under non-native states related to the folding process. Here we develop a method using quasielastic neutron scattering, combined with small-angle X-ray scattering and dynamic light scattering, to evaluate segmental motions of proteins as well as diffusion of the entire molecules and local side-chain motions. We apply this method to RNase A under the unfolded and molten-globule (MG) states. The diffusion coefficients arising from the segmental motions are evaluated and found to be different between the unfolded and MG states. The values obtained here are consistent with those obtained using the fluorescence-based techniques. These results demonstrate not only feasibility of this method but also usefulness to characterize the behavior of proteins under various disordered states.
-synuclein related to propensity to amyloid fibril formationFujiwara, Satoru*; Kono, Fumiaki*; Matsuo, Tatsuhito*; Sugimoto, Yasunobu*; Matsumoto, Tomoharu*; Narita, Tetsuhiro*; Shibata, Kaoru
Journal of Molecular Biology, 431(17), p.3229 - 3245, 2019/08
Times Cited Count：12 Percentile：49.22(Biochemistry & Molecular Biology)-synuclein (Syn) is an intrinsically disordered protein (IDP) with unknown function. Syn is known to form amyloid fibrils, which are implicated with the pathogenesis of Parkinson's disease and other synucleinopathies. Elucidating the mechanism of fibril formation of Syn is therefore important for understanding the mechanism of the pathogenesis of these diseases. Here, using the quasielastic neutron scattering (QENS) and small-angle X-ray scattering (SAXS) techniques, we investigated the dynamic and structural properties of Syn. These results imply that fibril formation of Syn requires not only the enhanced local motions but also the segmental motions such that the proper inter-molecular interactions are possible.
Fujiwara, Satoru; Takezawa, Yasunori*; Sugimoto, Yasunobu*; Wakabayashi, Katsuzo*
Journal of Structural Biology, 167(1), p.25 - 35, 2009/07
Times Cited Count：2 Percentile：4.97(Biochemistry & Molecular Biology)In neutron scattering and diffraction, information on variations of scattering length density of molecules of interest can be extracted by the contrast variation technique. In order to explore the possibilities of this contrast variation technique in neutron fiber diffraction, neutron diffraction measurements of skeletal muscles were performed. The neutron fiber diffraction patterns of frog sartorius muscles were measured in the relaxed state and the rigor state, in various D
O concentrations. It was shown that there were variations in the scattering length density of the protein regions in the unit cell of the muscle structure. Analysis of the equatorial reflections showed that the phase information of these reflections is obtained, that the scattering length density is different between the thick filament region and the thin filament region, and that the density of the thick filament changes as the state of muscle changes from the relaxed state to the rigor state.
Fujiwara, Satoru; Takezawa, Yasunori*; Sugimoto, Yasunobu*; Wakabayashi, Katsuzo*
Journal of the Physical Society of Japan, Vol.70, Supplement A, p.408 - 410, 2001/05
no abstracts in English
Fujiwara, Satoru; Takezawa, Yasunori*; Sugimoto, Yasunobu*; Wakabayashi, Katsuzo*
no journal, ,
In neutron scattering and diffraction, information on internal fluctuations or a variation of scattering length density of molecules of interest can be extracted by the contrast variation technique. This contrast variation technique was applied to measurements of neutron fiber diffraction of muscles. The neutron fiber diffraction patterns of frog sartorius muscles were measured in the relaxed state and the rigor state, in various D2O concentrations. It was shown that there were variations in the scattering length density distribution in the unit cell of the muscle structure. Analysis of the equatorial reflections showed that the phase information of these reflections is obtained, that the density projected onto a plane perpendicular to the fiber axis of muscle is different between the thick filament region and the thin filament region, and that the projected density of the thick filament changes as the state of muscle changes from the relaxed state to the rigor state.
