A View of the regulatory mechanism of muscle contraction from protein dynamics; A Neutron scattering study of muscle thin filaments

蛋白質ダイナミクスから観た筋収縮調節機構; 筋肉の細いフィラメントの中性子散乱による研究

藤原 悟; 松尾 龍人; 山田 武*; 柴田 薫  

Fujiwara, Satoru; Matsuo, Tatsuhito; Yamada, Takeshi*; Shibata, Kaoru

In order to investigate the regulatory mechanism of muscle contraction in terms of protein dynamics, we carried out neutron scattering experiments on the native thin filaments (NTF) in the presence and absence of Ca and F-actin using the dynamics analysis spectrometer at J-PARC. The elastic incoherent and quasielastic neutron scattering experiments showed that NTF in the -Ca state is more flexible than in the +Ca state, and that this difference in flexibility arises from the different distributions of the local atomic motions. Comparison with F-actin suggests that the differences arise from the regulatory proteins. These results imply that regulation of the protein dynamics plays an important role in the regulatory mechanism of muscle contraction.