Spontaneous transitions of actin-bound tropomyosin toward blocked and closed states.

ABSTRACT: After muscle contraction, myosin cross-bridge heads detach from thin actin filaments during relaxation. Structural and kinetic data of cross-bridge-thin filament interactions have shown that tropomyosin's position on F-actin is biased toward the blocked or closed states when myosin detaches. It is not clear if structural linkages between tropomyosin and myosin cross-bridge heads, or tropomyosin and Ca²⁺-free troponin, drive the process or whether tropomyosin movement is energetically independent of myosin and troponin influence. Here we provide in silico data about tropomyosin dynamics on troponin/myosin-free F-actin indicating that tropomyosin moves from the open state toward blocked- or closed-state positions on actin. To follow transitions inherent to tropomyosin itself on F-

SUBMITTER: Kiani FA 

PROVIDER: S-EPMC6314389 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature