Difference in dynamics between F-actin and myosin S1 measured by neutron scattering

中性子非弾性散乱によるF-アクチン及びミオシンS1のダイナミクス解析

松尾 龍人; 荒田 敏昭*; 小田 俊郎*; 藤原 悟

Matsuo, Tatsuhito; Arata, Toshiaki*; Oda, Toshiro*; Fujiwara, Satoru

中性子準弾性散乱を用いて、F-アクチン及びミオシンS1タンパク質のダイナミクスを調べた。J-PARCのAMATERASにおいて、F-アクチン及びミオシンS1の溶液試料を用いて実験を行った。ミオシンS1構成原子の運動の相関時間は、ヘモグロビン等他のタンパク質と同程度であったが、F-アクチンの相関時間はS1よりも小さいことが分かった。また、F-アクチン構成原子はS1よりも大きな空間を揺らぐことが分かった。これらの結果は、F-アクチンがミオシンS1よりも柔軟であることを示唆している。

The dynamics of F-actin and myosin S1 were studied by quasi-elastic neutron scattering (QENS). QENS measurements were conducted on DO solution samples of F-actin and S1 at 300 K using AMATERAS in J-PARC. The QENS spectra of proteins were obtained by subtracting those of DO buffer from those of DO samples. In the current analysis, it was found that while the correlation time of atomic motions of S1 was similar to that of other proteins studied so far, the correlation time of F-actin was shorter than S1. Furthermore, F-actin had a population of the atoms undergoing diffusive motions with larger amplitudes than S1. These results suggest that F-actin is more flexible than other proteins including S1.