Internal dynamics of F-actin and myosin subfragment-1 studied by quasielastic neutron scattering.
Various biological functions related to cell motility are driven by the interaction between the partner proteins, actin and myosin. To obtain insights into how this interaction occurs, the internal dynamics of F-actin and myosin subfragment-1 (S1) were characterized by the quasielastic neutron scattering measurements on the solution samples of F-actin and S1. Contributions of the internal motions of the proteins to the scattering spectra were separated from those of the global macromolecular diffusion. Analysis of the spectra arising from the internal dynamics showed that the correlation times of the atomic motions were about two times shorter for F-actin than for S1, suggesting that F-actin fluctuates more rapidly than S1. It was also shown that the fraction of the immobile atoms is larger for S1 than for F-actin. These results suggest that F-actin actively facilitates the binding of myosin by utilizing the more frequent conformational fluctuations than those of S1.
Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan.
Tatsuhito
T
Matsuo
Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
Toshiaki
T
Arata
Graduate School of Science, University of Hyogo, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan.
Toshiro
T
Oda
Neutron Science Section, J-PARC Center, Tokai, Ibaraki 319-1195, Japan.
Kenji
K
Nakajima
Neutron Science Section, J-PARC Center, Tokai, Ibaraki 319-1195, Japan.
Seiko
S
Ohira-Kawamura
Neutron Science Section, J-PARC Center, Tokai, Ibaraki 319-1195, Japan.
Tatsuya
T
Kikuchi
Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan. Electronic address: fujiwara.satoru@jaea.go.jp.
Satoru
S
Fujiwara
D000199:Actins / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement / Q000502:physiology; D002645:Chickens; D004548:Elasticity; D056004:Molecular Dynamics Simulation; D015879:Myosin Subfragments / Q000737:chemistry* / Q000378:metabolism*; D033363:Neutron Diffraction; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D011817:Rabbits
D000199:Actins; D015879:Myosin Subfragments
Actin; Myosin; Protein dynamics; Quasielastic neutron scattering