Myosin-based regulation of twitch and tetanic contractions in mammalian skeletal muscle.

ABSTRACT: Time-resolved X-ray diffraction of isolated fast-twitch muscles of mice was used to show how structural changes in the myosin-containing thick filaments contribute to the regulation of muscle contraction, extending the previous focus on regulation by the actin-containing thin filaments. This study shows that muscle activation involves the following sequence of structural changes: thin filament activation, disruption of the helical array of myosin motors characteristic of resting muscle, release of myosin motor domains from the folded conformation on the filament backbone, and actin attachment. Physiological force generation in the 'twitch' response of skeletal muscle to single action potential stimulation is limited by incomplete activation of the thick filament and the rapid inactivation

SUBMITTER: Hill C 

PROVIDER: S-EPMC8275128 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature