Internal dynamics of protein during amyloid fibril formation observed by neutron scattering

Fujiwara, Satoru; Yamada, Takeshi*; Matsuo, Tatsuhito; Takahashi, Nobuaki; Kamazawa, Kazuya*; Kawakita, Yukinobu  ; Shibata, Kaoru*

Amyloid fibrils, filamentous protein aggregates that are found as deposits in patients with various diseases, are related to pathogenesis of these diseases. Elucidation of the mechanism of the amyloid fibril formation is thus important for elucidation of the mechanism of pathogenesis. Since partial unfolding of a normal protein is likely to trigger the formation of the fibrils, characterization of "dynamics" of the protein should be important. Here we employ elastic incoherent neutron scattering (EINS) to characterize the dynamics of the protein during the amyloid fibril formation. We select hen egg-white lysozyme (HEWL) as a model system of the amyloid fibril formation. The EINS measurements on the solution samples of HEWL under the normal state and the amyloid-fibril states were performed with a high energy resolution near-backscattering spectrometer, DNA, installed at the materials and life science experimental facility at J-PARC, Tokai, Ibaraki, Japan. Differences in the dynamics were observed between HEWL under the normal states and the fibril state. The results of the detailed analysis is presented.