The Conformation of Myosin Heads in Relaxed Skeletal Muscle: Implications for Myosin-Based Regulation.

ABSTRACT: In isolated thick filaments from many types of muscle, the two head domains of each myosin molecule are folded back against the filament backbone in a conformation called the interacting heads motif (IHM) in which actin interaction is inhibited. This conformation is present in resting skeletal muscle, but it is not known how exit from the IHM state is achieved during muscle activation. Here, we investigated this by measuring the in situ conformation of the light chain domain of the myosin heads in relaxed demembranated fibers from rabbit psoas muscle using fluorescence polarization from bifunctional rhodamine probes at four sites on the C-terminal lobe of the myosin regulatory light chain (RLC). The order parameter 〈P2〉 describing probe orientation with respect to the filament axis had a r

SUBMITTER: Fusi L 

PROVIDER: S-EPMC4547144 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature