Dependence of thick filament structure in relaxed mammalian skeletal muscle on temperature and interfilament spacing.

ABSTRACT: Contraction of skeletal muscle is regulated by structural changes in both actin-containing thin filaments and myosin-containing thick filaments, but myosin-based regulation is unlikely to be preserved after thick filament isolation, and its structural basis remains poorly characterized. Here, we describe the periodic features of the thick filament structure in situ by high-resolution small-angle x-ray diffraction and interference. We used both relaxed demembranated fibers and resting intact muscle preparations to assess whether thick filament regulation is preserved in demembranated fibers, which have been widely used for previous studies. We show that the thick filaments in both preparations exhibit two closely spaced axial periodicities, 43.1 nm and 45.5 nm, at near-physiological tempera

SUBMITTER: Caremani M 

PROVIDER: S-EPMC7802359 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature